THE YEAR IN SCIENCE

SCIENCE FOR THE CURIOUS

® January/February 2017 TOP STORIES OF 2016 Detecting Alzheimer's Earlier Scary-Smart Artificial Intelligence Climate Change in Overdrive Next-Gen Spaceflight More Hobbitses, Precious!

The collision of two black . . . AND MORE! holes generates gravitational waves.

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Adélie penguins march to the nutrient- rich waters of Antarctica’s Ross Sea. A new international agreement will make the sea off limits to commercial fishing. See story on page 75. JOHN WELLER ON THE COVER Illustration by Lynette Cook. Insets from left: Lambert/Keystone/Getty Images; Tsafrir Abayov/Leon Levy Expedition; Zephyr/Science Source; Todd Marshall

4 DISCOVERMAGAZINE.COM SCIENCE FOR THE CURIOUS Website access code: DSD1702 Enter this code at: Discover Contents ® www.DiscoverMagazine.com/code January/February 2017 to gain access to exclusive subscriber content. BECKY LANG Editor In Chief DAN BISHOP Design Director EDITORIAL Einstein’s Ripples Can America Avoid KATHI KUBE Managing Editor 1 in Space-Time p.7 7 Another Flint? p.18 GEMMA TARLACH Senior Editor Finally found! Gravitational waves The city’s lead crisis points to a BILL ANDREWS Senior Associate Editor MARK BARNA Associate Editor offer a new way to study the universe. bigger water infrastructure problem. ERIC BETZ Associate Editor BY ERIC BETZ BY NATHANIEL SCHARPING LACY SCHLEY Assistant Editor DAVE LEE Copy Editor ELISA R. NECKAR Copy Editor The (Potentially) Habitable Looking for Planet Nine p.19 AMY KLINKHAMMER Editorial Assistant 2 Planet Next Door p.10 8 Yeah, Pluto got the planetary Contributing Editors Our closest star, Proxima Centauri, boot, but now a new “Ninth Planet” TIM FOLGER, JONATHON KEATS, could have an Earth of its own. contender emerges. BY KOREY HAYNES LINDA MARSA, KENNETH MILLER, BY ERIC BETZ STEVE NADIS, ADAM PIORE, COREY S. POWELL, JULIE REHMEYER, New Particle Flop Leaves STEVE VOLK, PAMELA WEINTRAUB, A New Enemy Emerges p.12 p.20 JEFF WHEELWRIGHT, 9 Physicists Unsure SPECIAL PROJECTS DARLENE CAVALIER ( ) 3 The first large outbreak of Zika Failure to find a new particle ART reveals its true impacts. BY LINDA MARSA prompts some hard questions. ERNIE MASTROIANNI Photo Editor BY NATHANIEL SCHARPING ALISON MACKEY Associate Art Director Oldest Human DNA Revises DISCOVERMAGAZINE.COM 4 Our Family Tree p.14 Did Lucy Fall CARL ENGELKING Web Editor NATHANIEL SCHARPING Web Staff Writer Ancient genes uncover a turning point 10 and Not Get Up? p.21 Bloggers in human evolution. BY BRIDGET ALEX A new theory of how the famous MEREDITH CARPENTER, LILLIAN FRITZ-LAYLIN, hominin died reignites debates of JEREMY HSU, REBECCA KRESTON, Biologists Create Organism how she lived. BY GEMMA TARLACH JEFFREY MARLOW, NEUROSKEPTIC, ELIZABETH PRESTON, SCISTARTER, 5 With Smallest Genome p.15 CHRISTIE WILCOX, TOM YULSMAN An artificial cell reveals the genes vital ADVERTISING Image of the Year p.96 for life. BY JONATHON KEATS STEVE MENI Advertising Sales Manager 888 558 1544 [email protected]

The Pace — and Problems — Index p.98 Rummel Media Connections 6 of Climate Change p.16 KRISTI RUMMEL Consulting and Media Sales 608 435 6220 Earth reached new and troubling [email protected] milestones in 2016. BY ERIC BETZ . . . PLUS 90 more stories MELANIE DECARLI Marketing Architect BOB RATTNER Research that made 2016 a DARYL PAGEL Advertising Services thrilling year in science. KALMBACH PUBLISHING CO. DANIEL R. LANCE Senior V.P., Sales & Marketing STEPHEN C. GEORGE Vice President, Content JAMES R. MCCANN Vice President, Finance NICOLE MCGUIRE V.P., Consumer Marketing JAMES SCHWEDER Vice President, Technology ANN E. SMITH Corporate Advertising Director MAUREEN M. SCHIMMEL Corporate Art Director Editor's Note KIM REDMOND Single Copy Specialist MIKE SOLIDAY Art and Production Manager A century-old prediction. A year of SUBSCRIPTIONS records. A millisecond of measurable In the U.S., $29.95 for one year; in Canada, $39.95 ON THE COVER for one year (U.S. funds only), includes GST, BN half-life. From the observation of 12271 3209RT; other foreign countries, $44.95 for Detecting Alzheimer’s Earlier p. 23 gravitational waves to the steady upward one year (U.S. funds only). Scary-Smart march of global temperatures to the CUSTOMER SALES & SERVICE Artificial Intelligence p. 37 800 829 9132 expansion of the periodic table, 2016 Outside the U.S. and Canada: 813 910 3616 Climate Change in Overdrive p. 16 delivered stunning finds. Dig in and Customer Service: [email protected] Digital: [email protected] Next-Gen Spaceflight p. 27 linger over this issue, which is jam- Back Issues: [email protected] More Hobbitses, Precious! p. 25 packed with the top 100 science stories EDITORIAL INQUIRIES He’s Right Again! p. 7 of the year. [email protected] 21027 Crossroads Circle, Waukesha, WI 53186 Archaeology in Action p. 36 Genetic Research p. 38 Dino Discoveries p. 42 Becky Lang, EDITOR IN CHIEF

January/February 2017 DISCOVER 5 Changing the future

Combine a passion for scientific exploration with a commitment to student learning, and the results can be astounding. Dean Andrew Lyon’s energy and dedication foster that kind of growth within the sciences at Chapman University. The success of in a word: his faculty and students helped spur creation of the brilliant new $130M Center forscheduled Science and to openTechnology, in 2018.

Andrew Lyon, Ph.D. Dean, Schmid College of Science and Technology, Chapman University National Fresenius Award of chapman Phi Lambda Upsilon, 2005 in a word: Camille Dreyfus Teacher-Scholar Award, 2003 Alfred P. Sloan Research Fellow, 2002 Beckman Young Investigator, 2000

chapman.edu TOP

FOUND: No. Einstein’s Ripples in

Black holes collide throughout the cosmos, Space-Time LIGO/A. SIMONNET LIGO/A. and now scientists can detect the resulting 1 gravitational waves.

January/February 2017 DISCOVER 7 2016 8 YEAR IN SCIENCE DISCOVERMAGAZINE.COM cosmos untilitreached Earth. and time, which swept across the as agravitational rippleinspace mass. That energy radiated away three timesoursun’sequivalent of energy,tremendous amount of the merged, theyalsosheda a second.Asthebehemoths they orbitedeachother100times times heavier thanthesun,and collided. Eachwas of dozens light-years away, two black holes LONG AGO toward eachother. Two blackholesspiral BILLIONS OFYEARSAGO in a galaxy 1.3 billion in agalaxy1.3billion space-time. a ripplein energy as releasing They merge, exactly acenturyago(left). the fabricofcosmos,almost massive objectsdistortspace-time, Albert Einsteinfirstsuggested

Letters published in February, when theresearch was David Reitze saidinearly it,” LIGOexecutive director gravitational waves. We did receiving alertsacross theplanet. it. Soon,elated scientistswere a humanhair—but LIGOsaw star systemby justthewidthof 25 trillionmilestothenearest was sosmall,itwould warp the space-time. Thedisturbance tiny of stretches andsqueezes tunnels caughtthewaves’ measurements insidemiles-long extremely sensitive laser less than10millisecondslater. LIGO facilityinLivingston, La., light,ithitthetwin speed of 2015. Then,traveling at the Hanford, Wash., inSeptember wave Observatory (LIGO)in Interferometer Gravitational- theory of relativity —which theory of Albert Einsteinusedhisgeneral almost exactly acenturyafter The historicfindingarrived composed amore perfectscript. 1.3 BILLION LIGHT-YEARS BILLION 1.3 “We have detected At bothobservatories, The wave firsthittheLaser No playwright couldhave . Physical Review smaller extentthanshownhere. pass through —thoughit’s toamuch shrink thenstretch everythingthey These gravitationalwaveseffectively LIGO isn’t boundby sight. in itsgravitational grip. But objectscaught behavior of existence by watching the could only inferablack hole’s Before LIGO, astronomers They emitandreflect nolight. Black holesare aptly named. ON BLACKHOLES SHEDDING LIGHT the cosmos. time, astronomers hadheard Christmas night.For thefirst captured asecondsignal an equipmentupgrade; they hunt inSeptemberfollowing immediately afterstartingto were surprisedtocatch one LIGO candetect.Soscientists black holes—generate waves spinning neutron stars, colliding cosmic events —supernovas, weak, only themostextreme excited rumors. for proof, aswell asmonthsof completed adecades-longhunt engineers, theconfirmation also physicists and generations of predict gravitational waves. For by warping space-time—to states that amasscreates gravity Because gravity isrelatively across thecosmos. The ripplesweeps

BLACK HOLES MERGING BY LIGO/T. PYLE. BOTTOM ROW FROM LEFT: LIOR MIZRAHI/GETTY IMAGES; LAMBERT/KEYSTONE/GETTY IMAGES; NASA ■ ■ ■ ■ ■ ■ ■ ■ ■ Its twin detectors and companion ■ ■ supercomputers can pick apart ■ ■ the strength and frequency of ■ gravitational waves to learn a black ■ ■ hole’s mass, spin and location. ■ ■ That makes LIGO akin to a new ■ ■ kind of telescope, one capable of ■ ■ listening to a previously invisible ■ universe. The first colliding binary ■ ■ black holes that LIGO detected ■ ■ were 36 and 29 solar masses — far ■ ■ bigger than expected. The second ■ pair were more in line with A LIGO technician tests one of the observatory’s mirror systems by shining light on its ■ surface at an angle. The work, which took place before sealing the chamber, is extremely ■ current theories. sensitive, requiring a white “bunny suit” and zero contamination. ■ ■ And as LIGO continues to detect ■ ■ more collisions, the data about die. Stars like our sun will grow as a whole. We’ve only barely ■ black holes will keep piling up. into behemoths called red giants started to do that. ■ ■ “We should have tens of detections before they shed their outer layers “Binary evolution is more ■ ■ over the next few years, and over and become an ethereal planetary complicated than single star ■ ■ a hundred through the end of the nebula. Larger stars — those with evolution,” says LIGO scientist ■ ■ decade,” says LIGO scientist Chad more than about eight solar masses Jolien Creighton of the University ■ Hanna of Pennsylvania State — will explode as supernovas. And, of Wisconsin-Milwaukee. “There’s ■ ■ University. “That’s enough to do theoretically, any star at least 25 a lot more processes that can ■ ■ some pretty significant astronomy. times bigger than the sun will end happen.” By cataloging their stellar ■ ■ That’s a big population.” its life as a black hole. corpses using LIGO, astronomers ■ But most stars in the Milky Way can learn more about how these ■ ■ HOW DO STARS LIVE AND DIE? are actually binaries or multiples, stars lived out their lives. ■ ■ By studying black holes, the part of a set. What happens After its initial findings, LIGO ■ ■ ultimate fate of many stars, LIGO to these stars when they die? took a break for upgrades before ■ also could help rewrite the textbook Understanding stellar pairs, and firing back up again in fall. As more ■ ■ version of stellar evolution. how one’s individual development gravitational wave detections stream ■ ■ Scientists have a pretty good affects the other, is fundamental in, from LIGO and its upcoming ■ ■ idea of how single stars live and to understanding stellar evolution ground- and space-based brethren, ■ ■ astronomers will get a better ■ picture of this invisible cosmos that ■ ■ SEPTEMBER 2015 Einstein saw so clearly.  ERIC BETZ ■ ■ Eventually it ■ reaches the LIGO ■ ■ facility in Hanford, The two facilities compare ■ Wash. . . . data to verify the discovery. ■ ■ ■ ■ ■ ■ ■ Hanford ■ ■ ■ ■ Livingston ■ ■ ■ ■ ■ ■ . . . and its twin ■ ■ in Livingston, ■ La., less than 10 See an exclusive LIGO gallery and more ■ milliseconds later. The Louisiana LIGO facility relied on precise observations at DiscoverMagazine.com/LIGO ■ ■ CLOCKWISE FROM TOP: MATT HEINTZE/CALTECH/MIT/LIGO LAB; LIGO LAB (2); ALISON MACKEY/DISCOVER LIGO LAB (2); LAB; HEINTZE/CALTECH/MIT/LIGO MATT TOP: CLOCKWISE FROM of lengthy laser beams to detect gravitational waves.

January/February 2017 DISCOVER 9 2016 10 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 2 Hints atExoplanet Abundance Earth’s SurpriseNeighbor deduced andfinally confirmed campaign, however, astronomers Thanks toamonthslongobserving obscured theplanetorbitingit. The star’s violentemissionslong neighbor, just4.2light-years away. Centauri, oursun’s nearest stellar perpetual sunset. a it withthesoftorange hueof onto itsworld’s surface, andlit outbursts. Itrained harshradiation dim andcoolprone toviolent The otherstarwas ared dwarf, evolved alongmuch different paths. stars —andlikely theirplanets— neighbor’s nightsky, but thetwo a steady, bright-yellow dotinits a much different star. Oursunwas a slightly larger world coalescedby AROUND THETIME That ruddy starwas Proxima Earth formed, tiny wobbles causedby thepull Proxima Centauri, lookingfor kept anear-constant vigilon from thestarevery 11.2 days. apossible planet coming signal of astronomers noticedtheperiodic Dot —bandedtogether after described EarthasaPale Blue in homage toCarl Sagan, who as thePale Red Dot—named scientistsknowncollaboration of decades. In2014,theinternational signal was hidden inplainsightfor could exist. water —and thuspossibly life— zone, where liquidsurface itsstar’s habitablein themiddle of Dubbed Proxima b, itsitssmack the planet’s existence inAugust. For monthslastyear, theteam Incredibly, theplanet’s ghostly their powerful flares. can create planet-like signalsduring starinthegalaxy,abundant typeof before. Red dwarfs, by farthemost suns have fooled astronomers careful becausethesesmall,violent discovery team.Theteamhadtobe Anglada-Escudé, who ledthe London astronomer Guillem says QueenMaryUniversity of sky high—very, very significant,” thedetectiongoes significance of everything together, andthen the the new data, andyou combine confirmation, published in old observations, ledtotheplanet’s decades- simultaneous analysis of thisnew data, aswell asa of anorbiting planet.Ananalysis of NASA’s Kepler spacetelescope “You take theolddata and Centauri sets. as Proxima from Proxima b possible view imagines a An artist Nature .

ESO/M. KORNMESSER ■ ■ ■ ■ ■ ■ ■ ■ ■ has detected thousands of ■ ■ exoplanets, so experts aren’t too ■ ■ surprised there’s a planet next ■ ■ door — but they are shocked this ■ one has a shot at hosting life. ■ ■ Proxima b hints that many of ■ ■ the Milky Way’s other roughly ■ ■ 75 billion red dwarfs might also ■ ■ have Earth-like planets. It’s ■ also good news for the Search ■ ■ for Extraterrestrial Intelligence ■ ■ Institute, which in 2016 launched ■ ■ a two-year search for alien signals ■ from the closest 20,000 red dwarfs. ■ ■ But despite its potential, ■ ■ Proxima b could still be barren. ■ ■ Because Proxima Centauri is ■ so much cooler than our sun, ■ ■ Proxima b is only potentially ■ ■ habitable because it orbits its star ■ ■ much closer than Mercury does ■ ■ the sun. We also don’t know its ■ makeup or if it actually has any ■ ■ water — or even an atmosphere. ■ ■ Luckily, Proxima b is perfectly ■ ■ LE RED DOT; SKATEBITER VIA WIKIMEDIA VIA SKATEBITER LE RED DOT; placed for follow-up studies. There ■ can be no exoplanet closer. And ■ ■ the next find is already revealing ■ ■ itself. Another periodic signal from ■ ■ the star hints at a second planet ■ — Proxima c. But astronomers Proxima b closely orbits ■ its star, but because it’s ■ still need many more nights at ■ a relatively cool red dwarf, ■ the telescope to know it’s not just that still puts the world ■ in the habitable zone. ■ the machinations of a violent ■  ERIC BETZ ■ star. ■ ■ ■ ■ ■ s The Alpha Centauri ear ■ t-y ■ system may be the sun’s h lig ■ nearest neighbor, but it’s 6 ■ Alpha Centauri A and B still almost unimaginably ■ far. Proxima Centauri lies ■ 4.2 light-years away, or ■ rs ■ about 25 trillion miles. yea ht- ■ lig ■ 4 ■ ■ ■ ■ ars Alpha Centauri A t-ye ■ Proxima Centauri gh ■ li Proxima Centauri 2 ■ CLOUD ■ RT O ■ Alpha Centauri B O ■ ■ ■ Proxima Centauri, the nearest star to Earth, is part of the ■ Alpha Centauri triple star system, seen in this view of the Sun ■ ■ CLOCKWISE FROM TOP: DEPARTMENT OF ASTRONOMY/UNIVERSIDAD DE CHILE/MAX PLANCK INSTITUTE FOR ASTRONOMY; ALISON MACKEY AFTER ESO/PA ALISON MACKEY ASTRONOMY; DE CHILE/MAX PLANCK INSTITUTE FOR ASTRONOMY/UNIVERSIDAD OF DEPARTMENT TOP: CLOCKWISE FROM southern hemisphere’s night sky.

January/February 2017 DISCOVER 11 2016 12 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM IN FEBRUARY, 3 syndrome, anervous system abnormalities orGuillain-Barre the birthdefect,othersevere fetal Brazil giving birthtobabies with women in thousandsof reports of U.S. —but suddenly there were 10,000live birthsinthe of rare —occurringin6out disabled. Microcephaly is leaving themseverely not develop normally, microcephaly may neurological deficits. skulls andsevere abnormally small in babies bornwith unprecedented spike physicians hadseenan country. Since2015, in theSouthAmerican borne Zikavirushadexploded pected for months:Themosquito- what doctorsinBrazil hadsus- global healthemergency confirmed Organization’s a declaration of of babieswiththebirthdefect. physicians haveseenaspikeincases in Recife,Brazil.Since2015,Brazilian withmicrocephalyon aninfantborn Stella Guerraperformsphysicaltherapy Babies bornwith A New Enemy Emerges the World Health the Zikavirus. known tocarry mosquito species is oneoftwo Aedes albopictus Rico, mostregions intheU.S. lack the U.S. Virgin Islands. Puerto Rico, AmericanSamoaand tions notonly inFloridabut alsoin than 30,000locally acquired infec- travel-associated casesandmore writing, theU.S. reported 3,989 Southern states. this Atthetimeof tion are alive andwell inmany mosquitoes that spread theinfec- Aedes aegypti are vulnerable tooutbreaks: The theU.S.2016. Andsomepartsof continental UnitedStates early in to 73countries. Itarrived inthe thesamebirthdefects. incidence of outbreak, theyfound anincreased at data from theFrench Polynesian When epidemiologists looked back founding variables.” Caseinpoint: when there are somany othercon- patterns inless-developed countries “But it’s difficult topickupthese Infectious DiseasesinMaryland. Allergy and National Instituteof Uganda in1947,andthere were The viruswas first reported in serious deficitslater. appeared tobehealthy developed disorder. Andeven babies who However, asidefrom Puerto Since then,thevirushasspread Zika hasbeenaround for decades.

a couple of outbreaks inthe a coupleof Fauci, director of the Fauci, director of all along,” says Anthony was happening at low levels patterns begantoemerge. Pacific islands, including “It’s conceivable that this outbreak inwhich clear French Polynesia in until theyhadasizable 2013, but itwas seen caused birth defects caused birthdefects as relatively harmless. didn’t Zika realize Public healthofficials and Aedes albopictus targeted therapy.” pathway, thisisabigsteptoward a Medicine. “Now that we know the biologist at USC’s Keck Schoolof the study’s leadauthorandamicro- brain development,” says Jae Jung, culprits “that fetal block normal the Zikavirusthat seemtobethe have isolated thetwo proteins in Southern California, researchers Zika’s effects. AttheUniversity of searching for ways toprevent says Fauci. theywork,researchers know if and anotheroutbreak —before will take at leastanotheryear — trials beganinJuly. However, it against Zikainfection,andhuman been shown toprotect monkeys effective vaccines.” infectionhighlighttheneedfor of treatment andtheloomingthreat any in Atlanta.“Still,thelackof Disease Control andPrevention theCentersfor Fertility Branch of theWomen’s of chief Healthand contained, says DeniseJamieson, outbreaks are likely tobesmalland will bepockets intheU.S.,” and accelerate transmission. “There packed urbanareas helpto and Brazil’s densely mosquito populations, conditions incubate in Brazil. Those fueled theepidemic weather that has the steamy tropical In themeantime, scientistsare Three vaccine approaches have Los Angeles  LINDA MARSA Mexico City

TOP: CDC/JAMES GATHANY. BOTTOM: MARIO TAMA/GETTY IMAGES ■ ■ ■ ■ ■ ■ ■ ■ ■ ZIKA ON THE April 2016: The CDC ■ confirms Zika can cause ■ ADVANCE ■ microcephaly and issues a ■ 1947: Scientists identify a public health alert. ■ ■ new virus in rhesus monkeys ■ in Uganda; first human cases May 2016: Puerto Rico ■ detected in Uganda and reports its first microcephaly ■ Risk of Local ■ New York Tanzania five years later. case linked to Zika. ■ Zika Transmission ■ None ■ 2007: First large Zika July 2016: Two human ■ Seasonal outbreak in humans, on vaccine trials begin, one led ■ Year round ■ the Pacific island of Yap in by the U.S. National Institutes ■ Micronesia. An estimated of Health and a second ■ Number of Travelers ■ 73 percent of residents by U.S. company Inovio ■ Orlando From Brazil become infected. Pharmaceuticals and South ■ 1,001–10,000 ■ Miami Korean firm GeneOne. ■ 10,001–50,000 May 2015: Brazil confirms ■ July 29, 2016: ■ Cancun 50,001–150,000 locally acquired Zika cases, Four cases ■ the first time the disease has of locally acquired Zika ■ Punta Cana been found in South America. infection are reported in ■ 150,001–300,000 ■ Miami-Dade and Broward ■ October-November 2015: counties in South Florida. ■ >300,000 ■ The virus spreads to the Since then, there have been ■ Caracas African island of Cabo Verde a total of 139 cases of local ■ ■ and at least six Central and transmission in the state. ■ South American countries. ■ ■ Aug. 1, 2016: The CDC ■ Bogotá November 2015: Brazilian issues a travel warning ■ ■ officials declare a public that pregnant women ■ health emergency after should avoid a specific ■ ■ seeing an extreme uptick neighborhood in Miami, one ■ in microcephaly cases in of the first times the agency ■ newborns. Amniotic fluid has done this because of ■ ■ from two pregnant women in a disease outbreak in the ■ Brazil tests positive for Zika, continental U.S. ■ ■ indicating the virus can be ■ Lima passed from the mother to Aug. 12, 2016: U.S. ■ ■ the developing fetus. government declares a ■ public health emergency in ■ ■ Santa Cruz Dec. 31, 2015: U.S. reports its Puerto Rico as a result of ■ de la Sierra first locally acquired Zika case the Zika epidemic. ■ ■ in Puerto Rico. At press time, ■ the island had 29,462 cases, Sept. 6, 2016: WHO ■ recommends practicing ■ Asunción according to the CDC. ■ safe sex for six months to ■ January 2016: The CDC avoid transmission, based ■ ■ detects Zika in the brain on findings that Zika can ■ tissue of babies born with be detected in semen for ■ ■ Santiago microcephaly. Brazil reports several months. ■ Montevideo 3,893 suspected cases of ■ ■ Buenos Aires microcephaly, including 49 Nov. 1, 2016: Stanford ■ deaths. More than a half- researchers report that Zika ■ ■ dozen more countries report infection impairs male fertility ■ cases. in mice models. ■ Researchers ■ identified airports ■ that were the final February 2016: The World As of November, there ■ Health Organization declares had been 30,000 cases of ■ destinations of ■ travelers leaving Zika a global public health Zika virus infection, 3,268 ■ areas of Brazil emergency. President Barack pregnant women with ■ ■ infected with Zika. Obama requests $1.9 billion evidence of Zika infection and They used those ■ in emergency funding to fight 25 babies born with Zika- ■ patterns to assess ■ global pathways Zika. Congress refuses to related birth defects in the ■ ■ KAMRAN KHAN, ST. MICHAEL’S HOSPITAL, TORONTO HOSPITAL, MICHAEL’S ST. KAMRAN KHAN, for the virus. approve the request. U.S. and its territories.  L.M.

January/February 2017 DISCOVER 13 2016 14 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 4 Revises OurFamily Tree Oldest HumanDNA A TECHNOLOGICALFEAT physical similaritiesandthe Europe andDenisovans inAsia. later splittingintoNeanderthalsin A secondbranch spread north, into modernhumansinAfrica. branch of early branch of chapter inhumanevolution, one years ago. Duringthismurky Pleistocene, 130,000to780,000 fossil collectionfrom theMiddle has yieldedthelargest hominin Sima delosHuesos our species. old —hasrevised thetimelinefor amillionyears fossils nearly half humanDNA from extraction of and legbone,thensequencethe individuals’genomestodeterminetheirlineage. Researchers were abletoextract DNAfrom a430,000-year-old hominintooth (above) Based ontheSimahominins’ The samplescamefrom Spain’s Homo cave, which evolved — After developing new technology, bacteria andothercontaminants. because theyare riddled with samples are oftenunreadable human DNA; even younger managed thefeat onsuchancient analyze. Researchers hadnever far more difficult toobtainand acell—something nucleus of required DNA from withinthe closely related toDenisovans. Sima samplefound itwas more mitochondrial DNA from one 2014, researchers analyzing rise toNeanderthals. Butin were thebranch that gave researchers assumedthey site’s European location, some Settling thisdisputedancestry Simadelos Huesos AFRICA NEANDERTHALS birthplace Hominin populations. different Eurasia into spread across Africa and evolved in Our genus EURASIA Matthias Meyer. human evolution,” says lead author pointinthetimelineof a “firm belong inourfamily tree establishes 430,000-year-old Simahominins in March. Knowing where the previous estimates. 550,000 years ago —double some modern humanssplittomore than revise thedate Neanderthalsand point”“firm allows researchers to differences between them.Sima’s genetic based onthenumber of can estimate when speciesdiverged and atooth. Sima genomefrom onefemur bone the Institute salvaged 0.1percent of a teamfrom Germany’s MaxPlanck to a Neanderthal ancestors, according definitive: Simahominins were here byanartist,were proto-Neanderthals. Spain’s revealed thattheindividuals foundat The oldesthomininDNAeveranalyzed With enoughdata, geneticists It was enoughDNA tobe Nature Sima delosHuesos study published OCEANIA BRIDGET ALEX BRIDGET site,re-created DENISOVANS

CLOCKWISE FROM TOP: ALISON MACKEY/DISCOVER; KENNIS & KENNIS/MSF/SCIENCE SOURCE; JAVIER TRUEBA/MSF/SCIENCE SOURCE ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Biologists Create Organism ■ 5 ■ ■ With Smallest Genome ■ ■ ■ THE PATHOGENIC BACTERIUM ■ Mycoplasma The organism’s creation comes at a time when ■ ■ genitalium has only 525 genes, the fewest of any living CRISPR gene editing, which allows scientists to ■ organism. The concise creation was a favorite with edit DNA in cells, is revolutionizing biology. Some ■ ■ geneticists, and it was one of the first organisms to be geneticists say that gene editing of existing genomes ■ ■ fully sequenced, a feat achieved in 1995 by biologist is a better path to manipulating organisms than ■ ■ J. Craig Venter and his team. creating a new genome design outright. ■ But Venter was not content with M. genitalium’s But both techniques have their place in biology, ■ ■ simplicity; he decided to create his own organism Venter says. Creating genomes offers a fresh platform ■ ■ with even fewer genes. He envisioned one so simple, on which to design life, while CRISPR works well ■ ■ it would reveal which genes are necessary for life and for altering existing genes. “We have used CRISPR ■ provide the ultimate chassis for genetic engineering. tools to make point mutations and to correct errors,” ■ ■ In March, the J. Craig Venter Institute in Venter says. “They are good tools, but to create ■ ■ California unveiled Mycoplasma mycoides JCVI- you need to make something that can be edited.” ■ ■  JONATHON KEATS syn3.0, the first artificial species ever created. It has ■ ■ 473 genes — a ■ staggering 149 ■ ■ of which are of ■ ■ unknown function. ■ ■ The “large number ■ of unknown genes ■ ■ argues that our ■ ■ standard tools of ■ ■ biological study ■ are very limiting,” ■ ■ Venter asserts. ■ ■ Syn3.0’s creation A variety of structures have been observed in the cultures of JCVI-syn3.0, the first minimal bacterial cell. ■ ■ was in part trial ■ and error, in which ■ COMPARING GENE NUMBERS ■ scientists added ■ Tomato 31,760 ■ and removed genes ■ Human 20,000–25,000 ■ until it sustained ■ ■ life and allowed E. coli (bacteria) 4,500 18% ■ for reproduction. 41% Cell membrane ■ Mycoplasma genitalium 525 Genome structure ■ Venter is now expression and function ■ Syn3.0 473 information ■ paring down the ■ ■ genomes of other Syn3.0 ■ organisms to “get ■ contains just ■ a better understanding of how much biological ■ 473 genes ■ knowledge we are missing.” ■ 17% ■ In addition to its genetic mysteries, syn3.0 is Cytosolic ■ smaller and grows faster than M. genitalium, metabolism ■ ■ making it more practical for lab work. Thanks to ■ ■ the organism’s creation, synthetic biologists are 17% 7% ■ Unassigned Preservation ■ learning more about customizing cells, such as for ■ function of genome information ■ development of highly effective drugs and energy ■ ■ CELL IMAGES: THOMAS DEERINCK AND MARK ELLISMAN/NCMIR THOMAS DEERINCK CELL IMAGES: alternatives to fossil fuels.

January/February 2017 DISCOVER 15 2016 16 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 6 CO hasn’t seenthat much remote Antarctica, which per million,including 400parts concentration of atmospheric carbondioxide passed agrimmilestone:an year onrecord. Theplanetalso flooding in2016,thehottest unprecedented drought and patterns inmemorybrought ONE OFTHE — andglobal this timeit’s permanent cycle, but scientistssay 400 ppmonaseasonal previously hadtopped rise. Somelocations catastrophic sealevel dire consequences, like threshold before we see 350 ppmastheuppermost Climatologists target

OF 2016’STOPCLIMATE STORIES. SEE DISCOVER’S COMPLETECOVERAGE 1960 2 for 4millionyears. 1970 PASS 400PPM PERMANENTLY

1980 CO GLOBAL 2 mightiest ElNiño

LEVELS .

1990 BETZ  ERIC of Climate Change Accelerate Accelerate Change Climate of Problems— —and The Pace 2000

2010

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few winters of heavy snow. a with even 2019, until recover winter helped forest-eating won’t it show models New

southern pine beetles settle normal. of half was — lifeblood Sierra Nevada snowpack — L.A.’s L.A.’s — snowpack Nevada Sierra

New England. And in California, reach the West. By summer, the the summer, By West. the reach

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##

66 million trees. A small silver when crumbled reservoirs

lining: A study in April found fill would Niño El that Hopes

13 that under certain conditions, DROUGHT WESTERN dead trees killed by bugs are

less likely to burn. shattering a decades-old record. decades-old a shattering 9 degrees F above average, average, above F degrees 9

unprecedented coralreefdie-offs. Record heatcauses SOUTHERN EXPOSURE and spring temperatures climbed climbed temperatures spring and

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landed in Louisiana in mid- via race dog sled the for snow

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killed dozens. A new study

SLUSH DOGS SLUSH

from the National Academy of STILL . . . Sciences shows climate change

moistens the atmosphere, first the For increasing flood risk. 14 ozone holeisfinallyhealing. Landmark studyshows ■ ■ ■ CLIMATE ■ ■ CRUISE ■ 16* Arctic sea ice ■ ■ vanished from the 14 ■ ■ Northwest Passage this On April 22, ■ summer, letting the cruise ship 12 ■ Crystal Serenity take about ■ ■ 1,000 tourists from Alaska 10 ■ to New York for the ■ ■ first time. 8 PARIS ACCORD ■ ■ Earth Day, 175 nations agreed 6 to keep global warming below ■ 2 degrees C. But scientists say the ■ non-binding Paris pact likely can’t 4 ■ hit its goal. And a study in March ■ found that even a 1.5 degree C ■ 2 ■ increase will severely degrade ■ coral reefs and hurt crop ■

productivity in the tropics.Summer MAR APR MAY JUN JUL AUG SEP OCT ■ ■ 2012 ■ ■ EPIC HEAT 2014 ■ temperatures brought record 2016 ■ ■ heat to the Middle East. A site 1981-2010 ■ in Kuwait hit 129.2 degrees F in Average ■ ■ July; the World Meteorological *Millions of square kilometers ■ Organization is investigating ■ if that was the hottest ■ ARCTIC SEA ICE ■ temperature ever recorded in ■ In September, Arctic ■ the Eastern Hemisphere. sea ice reached ■ ■ its second-lowest ■ extent ever ■ FARMS AND FAMINE ■ recorded; 2012 ■ Southern Africa entered the holds first place. ■ ■ second year of extreme drought, ■ which left cropland barren and ■

SPIRALING OUT ED HAWKINS/UNIVERSITY OF READING CENTER; AND ICE DATA SNOW NATIONAL DERPLAN13/SHUTTERSTOCK; ■ helped increase food prices. ■ Climatologist Ed ■ Hawkins has a new VATORY; ■ ■ COAL COLLAPSE way to look at rising ■ temps. By laying ■ has peaked in China, Coalthe world’s use ■ out months like a ■ largest polluter, and is falling clock, his plot shows ■ off earlier than expected, ■ the spiral toward ■ according to a a 2 degree C heat ■ analysis. That’s welcome news increase since 1880. ■ Nature Geoscience ■ as another fresh study showed ■ coal pollution prematurely killed ■ DEC ■

366,000 Chinese in 2013. ■ ■

■

■

■ ZOMBIE SPORES

■

blamed an anthrax outbreak ■

among Siberian reindeer on ■

■ A composite image shows an animal that died from the

■ how the extent of Arctic disease decades ago. Record heat M

Scientists P ■ A

sea ice in September 2016 melted permafrost and exposed E

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the infected carcass, killing a

compared with a 30-year ■

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U N ■ ■ ■ ■ ##Iceland’s ambitious experiment Human-caused warming # Humanity kick-starts a new ■ 74 75 96 ■ turns carbon dioxide into stone. claims its first mammal. geologic age: the Anthropocene. ■ CENTER: NASA'S SCIENTIFIC VISUALIZATION STUDIO. CLOCKWISE FROM BOTTOM LEFT: SCRIPPS INSTITUTE OF OCEANOGRAPHY, MAUNA LOA OBSER LOA MAUNA SCRIPPS INSTITUTE OF OCEANOGRAPHY, LEFT: CLOCKWISE FROM BOTTOM STUDIO. VISUALIZATION NASA'S SCIENTIFIC CENTER:

January/February 2017 DISCOVER 17 2016 18 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 7 cost billions. cost billions. plumbing would America’s lead Mich. Replacing pipes nearFlint, new water Workers place Health published inthe professor MonaHanna-Attisha. Herresearch, pediatrician andMichiganState University child’s entirelife-course trajectory,” saysFlint hurricane, thisissomethingthat . . . impactsa mistakes, canwelearnthistime? more children.Ifwefailedtolearnfromprior by Edwards,andwhichlikelyaffected even problems inWashington, D.C.,alsoexposed Flint bearsunsettlingparallelstothe2004lead were blatantlydisregarded.” Flint’s dangerouslyhighleadlevels.“Thoselaws Tech engineerlargelyresponsibleforexposing vulnerable,” saysMarcEdwards,theVirginia while theEPA admittednowrongdoing. reports warningofanimpendingleadcrisis, indicted onchargesofcoveringuporfalsifying classified ashazardouswaste. the waterwassotoxicitcouldbe into residents’homes.Insomecases, treat thewater, allowingleadtoflow when regulatorsfailedtoproperly chemicals tothearea’s agingpipes water sourceintroducedcorrosive A switchtotheFlintRiverascity’s drinking lead-lacedwaterforayearandhalf. after itwasdiscoveredthatresidentshadbeen FLINT, MICH.,MADEHEADLINES ANOTHER FLINT? FLINT? ANOTHER AVOID AMERICA CAN ESSAY “Unlike anyotherdisasterlikeafloodor But thisisn’t thefirstlead-in-the-watercrisis. “We havelawstoprotectourmost Nine cityandstateemployeeswere , assessedleadlevelsinnearly1,500 of American JournalofPublic this year this problem." children from to protect agencies paid fight thevery "We hadto get thetruthout.” “We hadtofightthemeverystepoftheway protect childrenfromthisproblem,”hesays. very lowlevelscancauselearningdeficits. especially forchildren,andstudiesshoweven essentially arbitrary. There’s nosafeleveloflead, its actionlimit—15microgramsperliteris certainly untenable.Somecitieshavereplaced as $50billion,makingtheclearsolutionalmost households. lead plumbingthatsnakesundersome6million Americans aredebatingwhattodoaboutthe a lifetimeoftreatmentforleadexposure.And enough resourcestoreplacepipesandprovide mental healthandelevatedincarcerationrates. issues rangingfromlearningdisabilities,poor a child’s brainarepermanentandlinkedto programs andhealthcare.Butlead’s effects on $400 millioninaidforinfrastructure,wellness Flint Riverwater. for elevatedlevelsofleadaftertheswitchto found thattwiceasmanychildrentestedpositive before andhalfafterthecontamination.She the city’s 10,000childrenundertheageof5,half before aGOPpresidential debateinMarch 2016. Demonstrators demandactiononFlint’s watercrisis “We hadtofighttheveryagenciespaid Replacing thementirelycouldcostasmuch Advocates arenowstrugglingtogather In contrasttoD.C.,Flinthasreceivedsome concentration leveltheEPA setsas And hepointsoutthatthelead nation’s agingwaterinfrastructure. institutional failuretomonitorthe remove lead. inexpensive waterfiltersthatcan encouraged residentstopurchase all theirpipes,whileothershave Edwards blamestheEPA foran  NATHANIELSCHARPING

THIS PAGE FROM TOP: DAVID GURALNICK/DETROIT NEWS/ASSOCIATED PRESS; CHIP SOMODEVILLA/GETTY IMAGES. OPPOSITE FROM TOP: NASA/JPL-CALTECH AND KHENG GUAN TOH/SHUTTERSTOCK; CALTECH/R. HURT(IPAC)/WORLDWIDE TELESCOPE ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 8 Looking for Planet Nine ■ ■ ■ A DECADE AFTER Pluto’s planetary demotion, the suddenly seemed not cute, but incontrovertible. So ■ ■ solar system may be back to nine planets. Like an where’s our new planet? ■ ■ unseen spider visibly tugging on a web of gravitational After their first announcement in The Astronomical ■ ■ strings, a hidden celestial body is luring distant space Journal, Brown and Batygin released a paper in March ■ rocks into clusters of orbits too conspicuous to ignore. ■ telling other astronomers where to look for the world. ■ At first, Caltech astronomers Mike Brown and They have a good idea of how the planet orbits, ■ ■ Konstantin Batygin thought their theory, published but not where on that path it may be right now. Its ■ ■ in January, was little more than a cute math trick: gravitational influence hints at a size around 10 times ■ ■ They calculated that a planet, a “mini-Neptune” Earth’s mass, Brown says, putting it firmly within reach ■ with an elongated orbit, could explain why some of earthly telescopes.  KOREY HAYNES ■ ■ objects beyond Neptune seem oddly grouped in space. ■ ■ But Brown is well aware of the historical context ■ ■ surrounding his tall claim and the skepticism that ■ should accompany it. Even though mathematicians ■ ■ announced evidence for Neptune before its 1846 ■ ■ discovery, many more assertions of hidden planets ■ ■ have fallen short. “Since 1845, every time anybody ■ looks up in the sky and sees something they don’t ■ ■ understand, they say it’s a planet,” Brown says. “And ■ ■ they’re always wrong.” ■ ■ Yet Brown and Batygin’s planet model kept making ■ ■ strange predictions that were borne out by the evidence An unusual set of orbits in the distant solar system suggested the ■ and difficult to explain by any other cause. Planet Nine gravitational influence of an unseen major planet. ■

January/February 2017 DISCOVER 19 2016 20 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 9 signal wasjustnoise. particle, butthe of amassivenew Collider sawsigns the LargeHadron Scientists using TO SOUL SEARCH SEARCH SOUL TO LEAVING PHYSICISTS NEW PARTICLE FIZZLES, how tofixit,”saysChrisMeyer, apostdoctoral Model] beingincomplete,andwe don’t know between matterandantimatter. explain gravity, forexample,orthe skewedratio a bigproblemforphysics.Themodel can’t Model’s lastmissingpuzzlepiece.Andthat’s mass —wasatriumphthataddedtheStandard — theparticlewhosefieldgivesmatterits The LHC’s 2012discoveryoftheHiggsboson model hasresistedallattemptsatrefutation. and allknownsubatomicparticles.Sofar, the three oftheuniverse’s fourfundamentalforces Model, adecades-oldframeworkencompassing have revolutionizedtheStandard ghost. Thesignalwasjustnoise. was nothingmorethanastatistical much-discussed “bump”intheirdata matter toquantumgravity. mysteries aboutanythingfromdark this potentialparticlemightsolve hundreds ofpapersabouthow of amassivenewparticle.Scientistswrote Collider inSwitzerlandshowedpuzzlinghints when twoexperimentsattheLargeHadron THE HYPESTARTED INDECEMBER2015 ESSAY “There arethingsthatpointat [the Standard Discovering anewparticlecould But furthertestsshowedthatthe how tofixit." we don'tknow incomplete, and Model) being at (theStandard things thatpoint "There are find.” promised usthatnewphysicswouldbeeasyto at RutgersUniversity. “Theuniversenever Matthew Buckley, atheoreticalphysicist for newdiscoveriesisfarfromexhausted. operating foryearstocome.So,thepotential of datafromtheLHC,whichwillcontinue other typesofexperiments.” find thatisnew, weneedtostartexploring Meyer says.“Andifthereisnothingelsethey know arethere,especiallytheHiggsboson,” disturbingly intact. other newphysics.TheStandardModelremains limits, hasn’t yetcapturedanysigns ofSUSYor machine’s powerandhasitrunningnearlyatits upgrade totheLHC,whichnearlydoubled complete theStandardModel.” it rightnow, themoretheoristscanworkonto we haveofthingsthatdon’t necessarilyfallinto researcher attheLHC.“Somoreevidence new particlemadeinproton collisions,illustratedhere. Hundreds ofscientificpaperstriedtoexplainapossible “What we’redoingisverydifficult,” says But scientistsarestillcombingthroughreams “We measurethethingsverywellthatwe  NATHANIELSCHARPING third oftheuniverse.Butlatest substance thatmakesupalmosta matter —themysteriousandinert a potentialexplanationfordark with ourworldonlyweakly, providing should eachhaveatwinthatinteracts posits thatparticlesinouruniverse supersymmetry, orSUSY. Thetheory to theStandardModeliscalled One oftheleadingupdates

TOP: CHRISTOPH BALLE/CERN. BOTTOM: THOMAS MC CAULEY/CERN ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 10 ■ Did Lucy Fall and Not Get Up? ■ ■ A PROJECT TO UNDERSTAND ■ ■ how Lucy lived might also show ■ ■ how she died. ■ ■ In 2008, anthropologist John ■ Kappelman and colleagues at ■ ■ the University of Texas at Austin ■ ■ scanned the partial skeleton of ■ ■ Lucy, the famous 3.18 million- ■ year-old Australopithecus afarensis ■ ■ discovered in 1974. ■ ■ Using super high-resolution ■ ■ CT scans, Kappelman originally ■ planned to learn more about ■ ■ Lucy’s movement and lifestyle ■ ■ — researchers have long debated ■ ■ how much time, if any, A. afarensis ■ ■ spent in trees. ■ In the images, Kappelman saw ■ ■ signs of a catastrophic fracture in ■ ■ Lucy’s upper arm, and multiple at bones,” says Kappelman. “We ■ ■ other fractures occurring shortly know what broken bones look like. ■ before her death. Kappelman We’re not clinicians, but this subset ■ ■

038/NATURE19332/2016 consulted clinicians who agreed it of fractures cannot be explained by ■ ■ was the type of severe break you’d geological processes. We looked at ■ ■ see in a car accident, or a rock- being trampled by, say, an elephant. ■ climber’s fall. But nothing we looked at ■ ■ Without cars or cliffs in her explained these injuries.” ■ ■ environment — Lucy was found John Kappelman (top) studied Harvard University ■ Lucy’s bones in new high-resolution ■ near a stream on a relatively flat CT scans (above and right) evolutionary biologist ■ landscape — the only way she and found injuries consistent Daniel Lieberman, who ■ with a great fall, suggesting ■ could have incurred those fatal was not involved in the ■ that Lucy’s species was a ■ injuries, concluded Kappelman’s tree-dwelling one. study, called it a “creative ■ ■ team, was by falling out of a tree. analysis” and saw the ■ ■ Published in Nature in August, “The suggestion that she team’s conclusions as ■ the study fanned the flames of the fell out of a tree is . . . neither reasonable. ■ ■ old ground- versus tree-dwelling verifiable or falsifiable, and “The fact is that ■ ■ debate. Critics also complained therefore unprovable,” he says. Lucy has all kinds of ■ ■ the team did not provide enough “Australopithecus afarensis was adaptations both for ■ evidence to support their essentially a terrestrial animal.” walking upright and for ■ ■ conclusions. Kappelman shrugs off the being arboreal,” says ■ ■ Donald Johanson, the controversy, noting he is a Lieberman. “The findings ■ ■ paleoanthropologist who found trained geologist, and that tell us one thing: She spent ■ Lucy more than 40 years ago, study co-author Lawrence ■ time in trees. In eastern Africa, ■ noted that other fossils discovered Todd has worked extensively if you want to sleep somewhere ■ ■ nearby also appear damaged, on the bones of bison driven at night, and you don’t have fire ■ ■ possibly from a stampede, or from off cliffs by prehistoric hunters. and you don’t have weapons, you’d ■ ■ the weight of sediment and other “Between Larry and me, we have probably want to climb a tree to ■ ■ FROM TOP: MARSHA MILLER/UT AUSTIN (2); REPRINTED BY PERMISSION FROM MACMILLAN PUBLISHERS LTD: JOHN KAPPELMAN ET AL./NATURE/10.1 JOHN KAPPELMAN ET PUBLISHERS LTD: REPRINTED BY PERMISSION FROM MACMILLAN (2); AUSTIN MARSHA MILLER/UT TOP: FROM material collecting over millennia. 80 years of experience of looking stay safe.”  GEMMA TARLACH

January/February 2017 DISCOVER 21 2016 22 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 11 a cyclone(bottom). due torainsfrom city nearlyhalted commerce inthe to flooding.InMay, is already prone to atemblor. Dhaka them vulnerable codes, making have laxbuilding city ofDhaka(top), including thecapital Bangladeshi cities, “DON’T PANIC,” Geoscience on theRichterscale. Japan’s 2011 Tohoku quake, amagnitude 9.0 earthquakes are along thesezones, including meet. Themostpowerful anddevastating zones occurunderwater where oceaniccrusts beneath land;allotherknown subduction time thistectonicprocess hasbeendiscovered shoving anotherunderneath it.It’s thefirst is actually asubductionzone:Oneplate is faultbeneath Indo-Burman Bangladesh continents’ slow danceacross Earth’s surface. moving horizontally pasteachotherinthe variety —tectonicplates oneithersidewere thestrike-slip long believed thefaultwas of toeasternIndia.ResearchersBurma) had stretching from Myanmar (alsoknown as ments positionedalongaknown faultline colleagues have collecteddata from instru- populated countries. the world’sone of poorest andmostdensely catastrophic earthquake risk for Bangladesh, startling discovery: auniqueandpotentially Steckler when asked about histeam’s The new research, published in But inJuly, theteamannouncedthat the For more thanadecade, Steckler and Potential MajorQuake Zone Bangladesh SitsAtop , shows that pressure isbuilding says geophysicist Michael Nature register a magnitude of 8.2orhigher.register amagnitude of the quake mightoccur, it’s possible itcould Although thestudy didnotaddress when along thezonebeneath Bangladesh. safety codes. in thecrowded countrymeeteven minimal significant seismic events, andfew buildings 12 milesthick.Sedimentcanliquefyduring which sedimentabout sitsatop alayer of that coulddotoBangladesh, size quake of construction andupdated disasterplanning. region prepare for theBig Onewithsafer Earth Observatory, recommends that the Columbia University’s Lamont-Doherty is occurring.Meanwhile, Steckler, basedat below thesediment,where thesubduction information about what’s goingondeep they don’t doanything.” don’t doanything andbeing socomplacent people inbetween beingsopanicked they Steckler says. “We should betryingtoget thepossibilities,”unblinking assessmentof Plate Indian The bigquestionishow much damage a Researchers are preparing togather more “More effort needstobeputintoan BANGLADESH Eurasian Plate 1,000+ 250 100 25 1 Active faults km per square People GEMMA TARLACH GEMMA INDIA CHINA Plate Sunda

FROM TOP: MUNIR UZ ZAMAN/AFP/GETTY IMAGES; MAMUNUR RASHID/NURPHOTO/GETTY IMAGES; JAY SMITH ■ ■ ■ ■ ■ ■ ■ Max. ■ Metabolic dysfunction ■ 1 ■ 0.9 ■ Big Data May Lead to Earlier ■ 0.8 ■ 12 0.7 ■ Alzheimer’s Diagnosis Vascular dysregulation ■ 0.6 ■ 0.5 ■ DIAGNOSING ALZHEIMER’S stages of Alzheimer’s progression, ■ 0.4 ■ disease before irreversible damage is according to the study published in Brain Regions 0.3 ■ done is one of medicine’s major goals. Nature Communications in June. They Functional impairment ■ 0.2 Abnormality Index ■ Now, a Canadian team has uncovered analyzed blood and cerebrospinal fluid ■ 0.1 ■ a technique that may detect the mind- samples, plus study participants’ cognitive 0 ■ robbing disorder at its earliest stages. skills. In 78 brain regions, they factored Min. ■ HC EMCI LMCI LOAD ■ Researchers at McGill University in in the pattern of amyloid concentration, Brain State Over Time ■ Montreal examined more than 7,700 glucose metabolism, cerebral blood flow, ■ ■ brain images from 1,171 people in various functional activity and brain atrophy. Thirty-year trajectories show Alzheimer’s ■ stages in patient brains: healthy state (HC), ■ Then, the team devised an algorithm to early/late mild cognitive impairment (E/ ■ re-create a 30-year trajectory for each of LMCI) and late-onset Alzheimer’s disease ■ ■ these biological factors. (LOAD). Each block shows a biological factor ■ (white label), with colored bands depicting ■ Scientists have long considered clumps brain regions. Cooler colors indicate fewer ■ of amyloid plaques — sticky, barnacle- abnormalities, warmer colors indicate more. ■ ■ like protein bundles — to be the first ■ sign of Alzheimer’s. But the Canadian important role . . . but the vascular ■ ■ team’s analysis, which harnessed the deterioration occurred first,” says Yasser ■ ■ power of big data to reveal previously Iturria Medina, the study’s lead author ■ Healthy brain undetected patterns, found that a marked and a neuroscientist at McGill. “These ■ ■ decline of the brain’s blood flow is the findings could lead to better diagnostics ■ earliest symptom. and therapies that target each one of ■ Alzheimer’s ■ brain “All the factors we looked at play an these factors.”  LINDA MARSA ■ ■ ■ ■ ■ SURVEY ■ ■ ■ ■ 13 Persistent Heat Decimates Coral Reefs ■ ■ ■ SCIENTISTS WATCHED A SLOW-MOTION PLAGUE ■ slowly recover, but they’ll be more vulnerable to disease and ■ unfold across Australia’s Great Barrier Reef in early 2016. less likely to spawn. And long-term warming trends will make ■ ■ Vast underwater forests containing staghorn and table corals, bleaching events more common and more severe in the coming ■ ■ normally golden brown, faded to ghostly white. Record decades. Says Eakin, “Things have changed. The ocean has ■ warming drove this phenomenon to an unprecedented scale: changed.”  DOUGLAS FOX ■ ■ Australian scientists announced in April that 93 percent of the ■ Great Barrier Reef had experienced bleaching. ■ ■ Some of the bone-white marine invertebrates were still alive ■ ■ at that point. Heat merely caused them to expel the colored, ■ microscopic algae that live inside them and provide food. ■ ■ But as the heat wave stretched from days to weeks, Coral Sea ■ ■ temperatures spiked more than 3 degrees Fahrenheit above ■ normal, and many corals succumbed to starvation or disease. ■ ■ By May, 35 percent of the northern and central reefs’ corals ■ were already dead or dying. ■ ■ The scale of death “was just absolutely phenomenal,” says ■ ■ Mark Eakin, who coordinates reef monitoring for the National ■ Oceanic and Atmospheric Administration. “This is the longest ■ ■ global bleaching event we’ve ever recorded.” ■ The bleaching began in mid-2014 and eventually affected ■ ■ 67 percent of coral reefs worldwide. Scientists expect it to wind ■ ■ down by early 2017, as global temperatures recede after three A diver examines coral near Heron Island in the Great Barrier Reef ■ ■ FROM TOP: Y. ITURRIA-MEDINA ET AL./NATURE COMMUNICATIONS/NCOMMS11934/JUNE 21, 2016; ALZHEIMER'S ASSOCIATION; XL CATLIN SEAVIEW SEAVIEW XL CATLIN ASSOCIATION; ALZHEIMER'S 2016; 21, COMMUNICATIONS/NCOMMS11934/JUNE AL./NATURE ITURRIA-MEDINA ET Y. TOP: FROM successive years of record heat. The surviving corals should in February. The site was one of the first to bleach.

January/February 2017 DISCOVER 23 2016 24 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 14 OF TECHNOLOGY MASSACHUSETTS INSTITUTE scientist Climate Solomon Susan Q & A FINALLY HEALING IS HOLE OZONE THE since 2000—andnotjustdue tonaturalvariations. height andareaareshrinking, reducingitsextentby1.5millionsquaremiles latest workshowsconclusively thattheprotocolisworking.Theozonehole’s chemicals, suchaschlorofluorocarbons. way forthe1989MontrealProtocol,whichbannedworst ozone-depleting discovered whyitwasthereinthefirstplaceback1986. Herfindingspavedthe published researchin penetrate ouratmosphere,isfinallystartingtoheal. in theozonelayeroverAntarctica,whichallowsharmfulultraviolet radiationto THIS YEARSAW Almost threedecadeslater, theozoneholestillhasn’t recovered,butSolomon’s Discover spoke with MIT climate scientist Susan Solomon, who not only spokewithMITclimatescientistSusanSolomon,whonot only the arrival of rare good news for the environment. The hole the arrivalofraregoodnewsforenvironment.Thehole Science in July showing that the hole is fading, but also in Julyshowingthattheholeisfading,butalso NATHANIEL SCHARPING NATHANIEL

DOMINICK REUTER ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 15 ■ ■ ■ ■ ■ ■ ■ More Hobbitses, ■ ■ ■ ■ Precious! ■ ■ ■ A NEW CHAPTER in the ■ ■ tale of Indonesia’s “hobbit” ■ fills in details of its backstory ■ ■ and provides a bittersweet ■ ■ legacy for the little hominin’s ■ September A partial hominin 2000 greatest champion. ■ jawbone ■ First described in 2004 from ■ ■ fossils discovered at Liang Bua, a ■ cave on the island of Flores, the meter-tall ■ ■ Homo floresiensis was instantly nicknamed after J.R.R. ■ Tolkien’s diminutive characters. However, researchers ■ ■ have argued about whether it was a distinct species or ■ ■ an isolated population of deformed or diseased modern ■ humans. (Dating analysis has established the fossils are ■ ■ more than 50,000 years old.) September ■ For two years, Indonesian authorities had denied ■ 2014 ■ researchers access to Liang Bua. That forced the hobbit’s ■ ■ discoverer, Australian archaeologist Michael Morwood, ■ and team members, including paleontologist Gert van den ■ ■ What have you seen that shows Bergh, to continue their research elsewhere on the island. ■ the ozone hole is closing? In Nature in June, van den Bergh and his team ■ Q ■ announced finding hominin fossils of at least three ■ ■ What’s happening now is we’re actually able individuals at a second site on Flores. The partial ■ A to show some evidence for it getting better jaw, skull fragment and six teeth unearthed at Mata ■ ■ finally, due to the changes made globally under the Menge are about 700,000 years old. The jawbone is at ■ Montreal Protocol to stop making these molecules. ■ least 20 percent smaller than those from Liang Bua, ■ So to me, it’s pretty amazing that we can see that. suggesting H. floresiensis may have evolved from an ■ ■ even smaller hominin. ■ “My co-authors and I are convinced the fossils ■ How much of the healing does ■ represent the direct ancestor of ■ Q the Montreal Protocol account for? ■ H. floresiensis,” says van den Bergh, ■ now with Australia’s University ■ I think it’s about half. The Science paper shows ■ of Wollongong. ■ A that you can pretty consistently explain about ■ For now, the Mata Menge half the decrease in the depth of the ozone hole. ■ fossils seem to expand the ■ And when it comes to the area, it’s even a little more timeframe of H. floresiensis ■ than half. ■ and confirm it was a distinct ■ ■ species. The vindication comes ■ ■ too late for Morwood, who died of ■ Q Are we out of the woods yet? cancer in 2013. Van den Bergh and ■ ■ his team continue to dig at Mata ■ Menge where, the paleontologist ■ No, it’s not completely healed; it’s a long way to ■ A being back to where it was. It’s not going to heal believes, “there must be many, ■ Homo floresiensis many fossils waiting to be ■ completely until the middle of the century, but it’s stood a meter tall. ■  GEMMA TARLACH ■ CLOCKWISE FROM UPPER LEFT: NASA OZONE WATCH (2); KINEZ RIZA (2) (2); WATCH NASA OZONE CLOCKWISE FROM UPPER LEFT: pretty clear that it’s on the road to healing. excavated.”

January/February 2017 DISCOVER 25 2016 26 YEAR IN SCIENCE

ZOBRIST DISCOVERMAGAZINE.COM 20,000 Puzzles inaBox! 33 POLYCUBE PIECES 52 PAGE CODE BOOK www.ZobristCube.com 16 CUBE 1 (855)962-7478 EVERY PERSON this data, we’ve known for three decadesthat thatAsians, story. thesamplesrepeat thesamedetailsof From studied, but becausethey’re mostly urbanWesterners andEast Arctic andAmazonBasin. the planet,colonizingenvironments asvaried astheHimalayas, how ourancestors—lanky, tool-usingapes —spread across published concurrently in 787 peoplefrom over 270populations. Theirfindings were people. from awiderpoolof Africa,researchers neededDNAhow humansmigrated outof evolved inAfricasome200,000years ago. To answer when and tell usahugeamountabout humanevolutionary history,” says Australia andPapuaindigenous peopleof New Guinea. linguisticandcultural diversity.maximize Thethird focused on studies drew samplesfrom isolated groups across theglobeto Millions of peoplehave theirDNA hadatMillions of leastpartof Three research groups sequenced high-quality genomes of Three research groups sequencedhigh-qualitygenomesof “Genomes from thesemore remote populations really can Ages 6-Adult & ’S DNA Africans We AreAll TM Nature contains part of thehumanstory: contains partof inSeptember. Two the of • Princeton International School of MathematicsandScience Princeton InternationalSchoolof • Ourstudentsare currently attending thefollowing collegesanduniversities: STEM 3.0 education including two years of originalresearch STEM3.0education requirement. including two years of • Brown, Caltech,Cornell, Duke, MIT, Notre Dame, Oberlin, Rensselaer A STEMfocused, International Boarding andDay HighSchool Small class size taughtby Smallclasssize bestinfieldfaculty with research experience. Polytechnic Design, UCBerkeley, Institute, RhodeIsland Schoolof Homo sapiens For more information or toscheduleavisit,please or see thePRISMS website at contact the Admissions Office at (609)454-5589 PRISMS

University of Michiganand many others.University of extremely rich.” computational biologist andastudy co-author. “Thisdata is things tobelearned,says NickPatterson, aBroad Institute specific diseasesandadaptations. There are stillmany earlier migrants. Papuans are probably thegenomesof frompercent of these theirexistence: About2 three studiesdetectedatrace of populations must have the mostly diedout.Only oneof ago. years 60,000 roughly Africa left that population small a from descend non-Africans all that indicate Americas the and Oceania Eurasia, of peoples between similarities Genetic conclusion: general same the to came they independently, thestudies. oneof Ph.D. studentandco-authorof Evelyn Jagoda, aHarvard University evolutionary genetics Researchers hopetousethenew data tofindpopulation- Older genomes analyzed and collected team each Although Homo sapiens  ALEX BRIDGET made it out of Africa,but these made itoutof www.prismsus.org on themove. depicts humans Africa southern pictograph from A 3,000-year-old

PETER CHADWICK/SCIENCE SOURCE ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The Falcon Has Landed. ■ ■ 17 ■ Now SpaceX Is Eyeing Mars ■ ■ ■ SINCE THE DAWN of the Space September, he said he’d send more ■ ■ Age, science fiction enthusiasts have spacecraft every 26 months for the ■ ■ fantasized about reusable rockets. foreseeable future. “We want to establish ■ Over the past year, Elon Musk and his a steady cadence so that there’s always ■ A Falcon 9 booster rocket successfully ■ company, SpaceX, made those visions a flight leaving, like a train leaving the touches down after a launch in April. ■ a reality. Now, the tech mogul has his station,” he told the IAC. ■ ■ sights set on a bigger, redder prize. Before departing for the Red Planet, that’s already been postponed twice. ■ ■ SpaceX has tried four times in though, SpaceX must show that the As if the vision of colonizing Mars ■ the past two years to land one of its monster next-gen rocket it needs to get wasn’t bold enough, Musk also revealed ■ ■ Falcon 9 rockets at sea; each exploded. there, the Falcon Heavy — essentially the Interplanetary Transport System ■ But in April, a Falcon 9 successfully three Falcon 9s strapped together — can at the September IAC, featuring a ■ ■ touched down on a drone ship in the also launch, land and relaunch. At dramatically scaled-up Falcon 9 that ■ ■ Atlantic — a first — after ferrying press time, the company, which would dwarfs any rocket ever built. Musk says ■ cargo to the International Space Station not comment on the subject, listed on the rocket’s companion passenger ship ■ ■ (ISS). Months earlier, in December its website an initial Falcon Heavy test could travel the entire solar system and ■ ■ 2015, SpaceX pulled off its first land launch at the end of 2016. Media reports enable a fully self-sustaining civilization ■ touchdown, at Cape Canaveral. The suggested it might take longer. (roughly 1 million people) on Mars ■ ■ company was planning to relaunch And September brought a reality possibly by 2060. Now, he’ll just have to ■ one of those successfully landed check. After eight successful 2016 flights, solve the numerous other engineering ■ ■ Falcon 9s for the first time in late 2016 a Falcon 9 exploded during routine and social challenges of such an ■ ■ or early 2017. fueling at Cape Canaveral. On Twitter, endeavor — and find a way to pay for it. ■ Musk hopes reusable rockets will make Musk called it “the most difficult and “It would be an incredible adventure,” ■ ■ colonizing Mars an affordable reality. complex failure we have ever had.” The Musk told the audience at the IAC ■ In April, the space entrepreneur said explosion could delay SpaceX’s 2017 meeting. “And life needs to be more ■ ■ he’ll send an unmanned spacecraft to plans to ferry NASA astronauts to the than just solving problems every day. ■ ■ Mars by 2018. And at the International ISS, which the space agency now expects You need to wake up and be excited ■ Astronautical Congress (IAC) in won’t happen until 2018 — a deadline about the future.”  ERIC BETZ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 18 ■ Electrons ‘Split’ in New Form of Matter ■ ■ ■ PHYSICISTS HAVE FOUND a new state of matter. That’s both over- and ■ understating it: The solid-liquid-gas trifecta still holds strong. What’s important ■ ■ about this new type of matter happens at the quantum scale — magnetically, ■ ■ the electrons behave as though they are split in two. ■ Researchers detected the behavior in a crystal of ruthenium trichloride ■ ■ at the Oak Ridge National Laboratory in Tennessee. They used a huge particle ■ ■ accelerator to shoot neutrons at the sample and observed the patterns that ■ formed when those neutrons bounced off and splattered on a detector. ■ ■ Electrons in the crystal acted together to produce so-called quasiparticles ■ — the electrons act like they’ve broken apart, though they haven’t literally. ■ ■ The quasiparticles produced here, called Majorana fermions, are their own ■ ■ antimatter. They suggest the presence of an unusual state of matter known ■ as a quantum spin liquid, which was predicted in this form a decade ago but ■ ■ has never before been observed. ■ Like many discoveries in the quantum world, this one, published online in ■ A Majorana fermion (bright white, center) creates ■ April in Nature Materials, could open new avenues in quantum computing and ■ rippled signatures in a quantum spin liquid ■ materials science. That’s a long way off, though. For now, the researchers say as neutrons are fired at a ruthenium trichloride ■ ■ TOP: SPACEX. BOTTOM: GENEVIEVE MARTIN/OAK RIDGE NATIONAL LABORATORY RIDGE NATIONAL GENEVIEVE MARTIN/OAK BOTTOM: SPACEX. TOP: they’re happy to have observed a new, weird behavior of nature.  SHANNON PALUS crystal (atomic structure shown to the left).

January/February 2017 DISCOVER 27 2016 28 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 19 Galsworthy, aBritishresearcher the U.K.wasleadingit,”saysMike world’s scientificsuperpower, and U.K. “Collectively, Europeisthe rethinking academiccareersinthe and graduatestudentsare out ofjointfundingapplications, have reportedpressuretoback Since thevote,Britishresearchers Agency logisticallypossible. CERN andtheEuropeanSpace participation inmajorprojectslike And EUmembershipmade scientists fromotherEUcountries. now hometomorethan18,000 scientists torelocatetheU.K., open bordersmadeiteasyfor research andinnovation.TheEU’s than itcontributedinfundingfor (currently about$3.8billion)more Britain received3.4billioneuros union: Between2007and2013, 28-country politicalandeconomic beneficiary ofmembershipinthe sector hadlongbeenabig much since.TheU.K.’s science “Brexit” referendum. European Unioninanationwide to kissoff, electingtoleavethe neighbors acrosstheChannel effectively hadtoldtheir voters intheUnitedKingdom the daytheywokeuptofindout gobsmacked onJune24.That’s could beforgivenforfeeling BRITISH SCIENTISTS That allmaychange,andsoon. Their moodhasn’t improved BREXIT WORLD BREXIT INAPOST-SCIENCE ESSAY post-EU nation. fears thatresearch wouldsuffer ina the dayofreferendum, sumsup in theUnitedKingdomonJune23, A banneratananti-Brexit protest funding cuts. could beabiggerblowthan competitive sciencescene,that exodus oftoptalent.Intoday’s worst-case resultcouldbean conflict can’t beresolved,the immigration. Ifthatfundamental motivated byunhappinesswith since many“Leave”voterswere tough sellforBritishpoliticians, core Europeandemandbuta its bordersopen,though.It’s a depends onBritainkeeping Brexit arrangement. “grandfathered in”toanypost- working intheU.K.couldstay, that foreignresearchersalready EU collaborations.It’s alsopossible  ANDREW CURRY  ANDREW Access toEUprogramslikely preserve theU.K.’s accessto home andnewtreatiesthat mix ofincreasedfundingat British sciencemaybea the best-casescenariofor reverses coursecompletely, a politicalupheavalthat will becritical.Barring seat.” hauled outofthedriver’s vote. “Nowwe’vebeen in therun-upto group ScientistsforEU who co-foundedthe The comingmonths 20 Marc Rayman. says Dawn’s engineer, chief rock,”world, notjustachunkof is ageologically complex alien Ceres sinceMarch 2015.“This a NASA spacecraft orbiting ocean. Ceres oncehostedanancient planet,suggestingthat the dwarf water toform —are spread across called carbonates —which need 2016 study found that minerals or perhaps abillionyears. Another craters millions over hundreds of geological process iserasing the that size. Theythinksome half haven’t measured oneeven to 500milesacross, but scientists be pockmarked withcraters up world. planetshould Thisdwarf a geologically active andwatery Ceres as an emerging picture of Science icy identity, asreported in 3-mile-high icevolcano. flow far, anditslowly built upa the Slurpee-like material couldn’t planet. OnceonCeres’ surface, magma builds volcanoes onour surface alongaduct—justas natural reached antifreeze the internaliceand slushy mixof Ahuna Monsformed when a on Earth,scientistsnow believe Mons. tall andlonely mountain: Ahuna Mars andJupiter, sportsaweirdly found intheasteroid beltbetween DWARF PLANETCERES, an Ice Volcano Ceres Hosts These hintscamefrom Dawn, Discovering AhunaMons’ After comparingitwithdomes inSeptember, adds to  LIZ KRUESI  LIZ

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DISCOVERMAGAZINE.COM 22 21 is targeted. A sequenceofDNAbases CRISPR geneeditingonhumanembryos. fertilization. TheUKhasapproved A humanembryodaysafterinvitro possible duetoadvances instem-cellscienceand for abeastinancient Greek mythology, are animal-human hybrid. These“chimeras,” named an conditions, thegeneticequivalent of scientists tocreate, undercarefully monitored animal embryos. Themove would free U.S. research that useshumanstemcellstocreate (NIH) proposed liftingafundingbanon science fact. science fictionfantasymight return, approaching human hybrids in REMEMBER THEFREAKISH editing gene Works:How It CRISPR-Cas9 DNA In August, the National Institutes of Health In August, theNational Institutesof sequence Target NIH Proposes Lifting 'Chimera' Research Ban Research 'Chimera' Lifting NIH Proposes The Island of Dr.The Islandof Moreau World ofHumanGeneEditing Regulating theBrave New animal- sequence. binds tothetargeted Guide RNAlocatesand the research. the legalandethicalimplications of aglobaldiscussionabout set off and governments by surpriseand unsuccessful, tookmany researchers first time. Theproject, though Cas9 onhumanembryos for the announced theyhadusedCRISPR- unprecedented speedandprecision. scientists cannow tweak DNA with gene-editing toolCRISPR-Cas9, need for regulation. have the beguntotake noticeof moves closertoreality, governments have beengenetically cutandpasted AS THEPROSPECT ? The “[The experiment] was actually In 2015,Chinesescientists Through therecently developed RNA Guide introduced intoothermammals, Wolinetz says. including projects inwhich humancellsare to considerallowing research involving chimeras, diseases, Alzheimer’s, schizophrenia,” shesays. that we weren’t able toseebefore —for brain technology allows ustomake animalmodels official. “Scientistsare excited becausethis methods, says CarrieWolinetz, anNIHpolicy drugsand vaccines than existing efficacy of gene-editing technology. PAUL SMAGLIK The NIHisestablishing asteeringcommittee Chimeras canprovide betterways totestthe of humanswho of strands ofDNA. guide RNAandcutsboth Cas9 enzymebindstothe Cas9 human embryos. restated itsbanongeneeditingof Heath National Institutesof related toinvitro fertilization. only tostudy developmental biology embryos for alimitedperiodand edit genesinnon-viable human a narrow capacity: Researchers can Institute inLondon,but only within human embryos at theFrancis Crick approved usingthemethodon should beregulated.” debates about how thesethings Wellcome Trust. “We needtohave the Britishmedicalresearch charity Katherine Littler, policyadviser at quite fortunate inaway,” says Meanwhile intheU.S., the In February, theUnitedKingdom

chimera ofGreek mythology. fifth centuryB.C.depictsthe A bronze statuefrom the silencing it. . . . orthegeneisleftasis, adds ageneticsequence. . . by ageneeditor, which The cutisrepaired  PAUL SMAGLIK Mutation X

FROM TOP: ZEPHYR/SCIENCE SOURCE; ALISON MACKEY/DISCOVER AFTER GENOME RESEARCH LIMITED; RAPHAEL GAILLARDE/GAMMA-RAPHO/GETTY IMAGES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Finding China’s ■ ■ 23 ■ ■ 24 ■ Great Flood ■ ■ Picky ■ ACCORDING TO ANCIENT Chinese texts that mix historical events with ■ ■ legend, about 4,000 years ago a hero named Yu tamed a flood and went on ■ Primes ■ to become China’s first emperor. The story may be largely myth, but geologic ■ ■ PRIME NUMBERS — evidence reported in Science this August suggests that at least the Great Flood ■ was real — and really Great. ■ those that are divisible ■ only by 1 and themselves “It’s sort of the equivalent of if we found evidence of Noah’s flood from ■ ■ — aren’t quite as random the Bible,” says Taiwan University archaeologist ■ ■ as mathematicians David Cohen, co-author of the study. ■ thought. In particular, ■ About 800 miles west of Beijing, along a ■ they seem to have definite 30-mile stretch of the Yellow River, researchers ■ preferences about the final ■ found a variety of sediments, indicating a ■ digits of the primes that ■ landslide, a lake and a violent flood in the ■ follow them. ■ Primes especially distant past. Based on the extent of these ■ deposits, they were able to reconstruct the ■ dislike following primes ■ with the same final digit catastrophic events: A landslide dammed the ■ ■ as their own. Among river, forming a lake several hundred feet deep. ■ ■ the first billion primes, After several months the dam burst, releasing ■ for example, primes a torrent of nearly 100 million gallons of water ■ ■ ending in 9 follow a per second. ■ prime also ending in 9 ■ Flood sediment settled over collapsed ■ only 60 percent as often A 19th-century Japanese ■ buildings and crushed bodies some 15 miles woodblock print depicts ■ as they follow a prime downstream at the archaeological site of Lajia. Chinese hero Yu’s mythic battle ■ ending in 1. against a monstrous flood. ■ But the waters didn’t flatten the village or kill ■ In a paper submitted ■ in March, Kannan its residents — an earthquake caused the death ■ RUSSIA ■ Soundararajan of and destruction, and probably also triggered ■ ■ Stanford University and the dam collapse that led to the flood. ■ Robert Lemke Oliver of By radiocarbon dating human bones and ■ Lajia excavation ■ Tufts University showed rubble at Lajia, researchers placed the flood at ■ that the pattern holds ■ approximately 1920 B.C., roughly coincident CHINA ■ among the first 400 billion  BRIDGET ALEX ■ with Yu’s legendary dynasty. ■ primes and offered a Yellow River ■ possible explanation for it. ■ ■ The tendency diminishes ■ i ■ as primes get bigger, but ■ only very slowly. Vietnam ■ ■ The discovery ■ ■ shocked mathematicians, ■ because a fundamental ■ ■ understanding about ■ prime numbers is that ■ ■ they behave much like ■ ■ random numbers, without ■ orderly patterns in their ■ ■ distribution. The new ■ information shows that ■ ■ this randomness is more ■ ■ complicated than had been In central China’s Jishi Gorge, gray sediment layers — now well above the Yellow River — ■  JULIE REHMEYER ■ FROM TOP: MUSEUM OF FINE ARTS, BOSTON/WILLIAM STURGIS BIGELOW COLLECTION; ALISON MACKEY/DISCOVER; QINGLONG WU QINGLONG ALISON MACKEY/DISCOVER; STURGIS BIGELOW COLLECTION; BOSTON/WILLIAM ARTS, MUSEUM OF FINE TOP: FROM believed. indicate an ancient lake created in a landslide and then released by a devastating earthquake.

January/February 2017 DISCOVER 31 2016 32 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 25 NATIONAL LABORATORY LAWRENCE LIVERMORE chemist Nuclear Dawn Shaughnessy Q & A PERIODIC TABLE?PERIODIC ENDTHE OF THE credited withthefind. Lawrence LivermoreNational LaboratoryinCalifornia,whowasontheteam that question,amongothers, tonuclearchemistDawnShaughnessyofthe pushes scientiststowonder:Are therestillelementslefttodiscover?We put some arestableformeremilliseconds beforetheydecay. And this difficulty into oneheavy, brand-newelement. together lighterelementsatever-higher energies,hoping they’dfuseperfectly atom usingaparticleacceleratorinDubna,Russia.Foryears, theysmashed tennessine andoganesson.Ittookthescientiststhreemonths tomakeeach scientists addedfournewelementstotheperiodictable:nihonium, moscovium, AND THENTHEREWERE118. But don’t expecttoseethesenewelementsputinto use anytimesoon—  ERIC BETZ InJanuary, aninternationalcollaborationof

PETERCREDIT DASILVA ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 26 ■ ■ ■ ■ ■ ■ Drug Couriers ■ ■ ■ ■ for Brain Injuries ■ ■ ■ A SHORT PROTEIN FRAGMENT, OR PEPTIDE, may lead ■ ■ the way to healing traumatic brain injuries, a primary cause ■ ■ of death and disability among youth. ■ ■ If these elements survive mere Currently, drugs to treat such injuries are injected ■ Q seconds and don’t exist in directly into the brain — an invasive technique — or into ■ ■ nature, what’s the point? the bloodstream, which allows the medication to spread ■ ■ throughout the brain, causing harmful side effects. Attaching ■ We’re getting into fundamental ■ drugs to the new peptide, called CAQK, would avoid these ■ A nuclear forces and the properties problems. The peptide, just four amino acids long, binds ■ of the nucleus. Basically, what is the ■ to a protein complex ■ limit of the existence of matter? What ■ that’s more abundant ■ element do we get to when it just will CAQK peptide Control peptide in injured areas and ■ not be an element anymore and we ■ can therefore carry ■ can honestly say that we’ve hit the ■ the therapy through ■ limit? It’s going to be important for ■ refining nuclear models. the blood straight ■ ■ to the damaged sites. ■ ■ To find the ■ What can the new elements chemical courier, a ■ teach us about our universe? ■ Q team led by Erkki ■ ■ Ruoslahti of Sanford In a mouse brain, the CAQK peptide binds ■ After the Big Bang, these elements to injured sites more effectively than the ■ Burnham Prebys control. (Cooler colors signal lower peptide ■ A all existed for a very short period ■ Medical Discovery levels; warmer colors signal higher levels.) of time. That’s something that we ■ Institute in California ■ really didn’t have a handle on years ■ ago because people said we would tested 1 billion random combinations of amino acids — just ■ ■ never move past element 100. Now we one robustly bound specifically to injured brain tissue of ■ ■ know there are certain configurations mice and humans. The results were published in Nature ■ in the nucleus that make it particularly Communications in June. ■ ■ stable at these higher numbers. And “We get more of the drug to go to the injury and to ■ we’re getting a handle on what the ■ stay there,” Ruoslahti says. Now, older treatments that ■ nucleus really looks like. ■ were abandoned because they didn’t latch to injured areas ■ or had negative side effects could be revived.  TEAL BURRELL ■ ■ ■ Are we close to completing ■ Q the periodic table? CAQK peptide Control peptide ■ ■ ■ ■ I think probably at some point ■ A there will be [element] 119 and ■ ■ likely [element] 120. It’s just that the ■ ■ half-lives now are getting so short ■ — we’re at milliseconds with 118 — ■ ■ and the production rates of these ■ things are extremely small. We make ■ ■ one atom in a three-month period. ■ ■ Something is going to have to change The 1-in-a-billion CAQK peptide (dark blue) also targets injured sites ■ ■ REPRINTED BY PERMISSION FROM MACMILLAN PUBLISHERS LTD: REPRINTED BY PERMISSION FROM MACMILLAN JUNE 2016 (3) COMMUNICATIONS/10.1038/NCOMMS11980/28 AL./NATURE MANN ET AMAN P. to push out heavier elements. in human brain samples, showing its potential for precise drug delivery.

January/February 2017 DISCOVER 33 2016 34 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 27 debate. Open-accessadvocates,likeSci-Hub’s founder, access toresearchinthedigitalageintoapublic copyright law. pirated articlesforfreedownload—aviolationof started in2011thatnowhousesroughly60million journals, filedalawsuitagainstSci-Hub,website ings? In2015,Elsevier, amajor publisherofacademic for-profit publishersbeabletocopyrightthefind- IF GOVERNMENTSFUND within] theirbudget. on howto[publishresearch fronted witharealdebate community wouldbecon- example, theuniversity journal subscriptions,for overheads forpaymentof agencies denieduseoftheir very expensive.Iffunding the subscriptionmodelis on apaper-by-paper basis, “free.” Therealityisthat, in asubscriptionjournalis impression thatpublishing Authors areunderthe institutional overheads. are paidforthrough slow tochange. underlying mentalitiesare information technology, the hugeadvancesin scientific discovery. Despite in thecommunicationof inefficiencies anddelays century. Thissituation causes the middleof20th processes establishedduring seminated accordingto being validatedanddis- Too manyoftheseare still growing exponentially. year, anumberthat’s scientific articlesper Society produces2.5million publishers open-access one of the largest of editor Executive Fenter Fred Today, subscriptions In 2016, the case turned an ongoing debate about In 2016,thecaseturnedanongoingdebateabout

Frontiers , Access for Battle scientific research, should scientificresearch,should term in the1970sand’80s.The repositories werelaunched open-access journalsand to shareresearch.Thefirst was createdinthe1960s internet’s predecessor] In fact,it’s older. [The the internetandweb. literature isasold Open accessforresearch readers for free are that journals to publish inresearchers online Access Project Director of the Suber Peter this beautifulopportunity. money, it’s foolishtopassup for impactandnot marginal cost.Ifyouwrite a globalaudienceatzero internet canshareitwith is borndigital,andthe All newresearchliterature without losingrevenue. to consentopenaccess money, whichfreesthem articles forimpact,not century. Researcherswrite invented inthemid-17th since scholarlyjournalswere authors, andtheyhaven’t buy theirarticlesfrom Sci-Hub isanewcomer. Access Initiativein2002. by theBudapestOpen Scholarly journalsdon’t open access Harvard Open Harvard , which encourages , which encourages was coined scientific journal papers journal scientific and open-access traditional never goaway. are responsibilitiesthat record andpromotingethics maintaining thescientific and preservation.Plus, curation, publication rial boards,peerreview, managing journals,edito- same dutiesrelatedto Elsevier stillperformsthe more importantthanever. publishers] arebecoming to thepublic. more broadly, including to disseminateresearch publishers whoallwant many authors,fundersand driving openaccessare for nearly10years.What’s and that’s beenveryclear scholarly communications, in academicpublishingand Open accessisheretostay at of access andDirector policy Alicia Wise on thefutureofscientificpublishing. sponsible science. like Sci-Hubcouldlowerstandardsandpromoteirre- “gatekeeper” publisherslikeElsevierworrythatsites dreds totensofthousandsdollars.Buttraditional afford journalsubscriptions,whichrangefromhun- exclude scientistswhoworkatinstitutionsthatcan’t research promotesfasterinnovation.Anditdoesn’t Alexandra Elbakyan,contendthatfreelysharing Elsevier [But traditionalacademic , a large publisher of of publisher , alarge Discover asked all sides to weigh in askedallsidestoweighin restricting access profits donotdependon open-access model,where will havetoswitchan unprofitable, andpublishers subscription-based businesses amendment willrender and education.Suchan law, atleastinscience to abandonthecopyright progress ofscience. heavily restrainingthe flow ofinformation,thereby higher profits—tofree with theonlygoaltoextract unnecessary obstacles— publishing modelscreate make arequestandwait. idea, ratherthanhavingto a paperwhenyougetan different whenyoucanread the [paperasa]PDF. Butit's who hasaccesstosendyou or askinganotherresearcher such asemailingtheauthor paywalled papersexisted, alternative optionstoget it. WhenSci-Hubstarted, required paperandread put inthereferencefor access hastobesimple:Just to researchpublications.The easy andunobstructedaccess createdSci-Hub]toprovide [I of and founder student Graduate Alexandra Elbakyan Sci-Hub The best solution I see is The bestsolutionIseeis Current academic

 ERIC BETZ .

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PHILISTINE HISTORY was written Tel Ashkelon. by their rivals, and unfortunately “Seeing the Philistines face to face for them, that text became a best- . . . allows us to proceed for the first seller: the Bible. According to the time from a really solid foundation,” Old Testament, Philistines were a says Daniel Master, Ashkelon constant threat, producing infamous co-director and Wheaton College villains like the temptress Delilah and archaeologist. giant Goliath. Their bad reputation Master and Aja were tipped off persists even today: Their name is about the cemetery in 2013, when a shorthand for anyone averse to retired Israeli surveyor insisted he’d culture and learning. found human bones and pottery just “But the archaeology has shown outside Ashkelon’s gates during a them to be more than that,” says construction project decades ago. Aja Harvard archaeologist probed the grounds with Adam Aja, assistant Over the years a backhoe until he struck director of excavations archaeologists bone, locating the long-lost at Tel Ashkelon, a major have unearthed burial grounds. Philistine port city in Since then, the Ashkelon southern Israel. buildings team has been exhuming Philistines left no and artifacts and analyzing the skeletons written records, but over that show of Philistine men and the years archaeologists Philistines were women, from infancy to have unearthed buildings cosmopolitan. old age. Some individuals and artifacts that were resting alone on show Philistines were their backs or sides; others cosmopolitan. Scholars were jumbled in groups or believe they migrated cremated. The modest grave from the Aegean around goods include tiny jugs, 1200 B.C. to the Levant bracelets and weapons. where, for centuries, their Digging at Ashkelon Remains of a mercantile culture thrived ended in summer, but Philistine laid to rest nearly — until their cities were research continues in the 30 centuries demolished by Babylonians laboratory. At press time, ago at a newly around 600 B.C. the team planned to present discovered cemetery in Tel “Archaeologists have preliminary results in Ashkelon, Israel. done an excellent job Modest grave goods November. Aja hopes ancient unearthed in the constructing a plausible Philistine cemetery DNA and radiocarbon picture of who these Iron included weapons, analyses, currently Age people were just jewelry and this juglet. underway, will resolve the based on the scraps we’ve biggest mysteries of the had available to us,” Aja says. Philistines: Where did they come from But to confirm the origins and fates and where did they go? Were they of Philistines, archaeologists needed wiped out by their enemies or merely more than scraps; they needed absorbed by them? Philistine bones. “Authors are not always kind They finally got them. In July, to their enemies in texts,” he researchers announced that they says. “We want to try to set the had found over 210 skeletons from record straight.”  BRIDGET ALEX, the first Philistine cemetery ever AN ANTHROPOLOGIST WHO HAS BEEN A MEMBER

discovered, just outside the walls of OF THE ASHKELON TEAM FOR SIX SEASONS LEVY EXPEDITION (2) ABAYOV/LEON TSAFRIR

36 DISCOVERMAGAZINE.COM ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 29 ■ Go, Go AlphaGo ■ ■ ■ ARTIFICIAL INTELLIGENCE wickedly difficult to master because ■ ■ experts said it wouldn’t happen of the near-infinite number of legal ■ ■ in 2016 — even 2030 would be moves on the board’s 19-by-19 ■ ■ a stretch. But it did. grid. AI researchers have pushed ■ In March, AlphaGo, a program for years to build an algorithm that ■ ■ from Google’s AI research could handle this complexity and ■ The ancient Chinese board game Go ■ company, DeepMind, defeated topple human Go champions. ■ has a near-infinite number of legal moves, ■ 18-time world champion Go AlphaGo pairs a traditional making it incredibly complex. ■ player Lee Sedol, 4-1, in a historic Monte Carlo tree search ■ ■ showdown in South Korea. (identifying an optimal move by with two kinds of artificial neural ■ ■ Go is an ancient Chinese board playing the remainder of the game networks: one that predicts the next ■ ■ game that’s elegantly simple, yet over and over in its “imagination”) move and another that evaluates the ■ ■ winner of each board position. ■ Before playing a human, ■ ■ AlphaGo used its neural networks ■ ■ to analyze 30 million moves ■ ■ made by human experts, and then ■ discovered new strategies by playing ■ ■ itself thousands of times. ■ ■ During the showdown with ■ ■ Sedol, AlphaGo made a move a ■ professional player would never ■ ■ make. Move 37 was so unorthodox, ■ ■ Sedol left the room to regain his ■ ■ composure. Was it a lucky mistake? ■ ■ Or had AlphaGo advanced beyond ■ human understanding of the game? ■ AlphaGo, a program by Google’s AI company called DeepMind, defeated champion player ■ Lee Sedol (seated right) in March at the notoriously difficult game Go.  CARL ENGELKING ■ ■ ■ ■ ■ ■ ■ ■ 30 ■ Crowdsourced Study Pinpoints Depression Genes ■ ■ ■ DEPRESSION AFFECTS SOME 350 million was crowdsourced: The data came via personal ■ ■ people worldwide, costing billions in health care genomics company 23andMe, from people who ■ expenses and decreased work productivity, yet consented to participate anonymously. ■ ■ the illness is poorly understood on a biological The study involved participants of ■ ■ level. But we’re getting closer. European descent exclusively, but co-author ■ Scientists have pinpointed 15 regions in Roy Perlis, a researcher at Massachusetts ■ ■ DNA associated with depression. The study, General Hospital, notes it’s standard method ■ published in August in Nature Genetics, to focus on one group as a starting point, since ■ ■ analyzed the genetic variations of 75,607 previous research shows genetic markers can ■ ■ individuals who reported having depression, vary by ethnicity. ■ and 231,747 healthy controls. It found that “An important next step is trying to ■ ■ genes associated with depression are involved understand how important these genes are in ■ in brain cell development, and that there was people of different ancestries,” says Perlis, who ■ ■ overlap between these genetic regions and adds that new treatments are still a long way off. ■ ■ those linked to schizophrenia and other mental “The hard work is ahead of us; it’s just that now ■  STEVEN POTTER ■ FROM TOP: ED JONES/AFP/GETTY IMAGES; GOOGLE DEEPMIND; YOUJIN JUNG/SHUTTERSTOCK YOUJIN GOOGLE DEEPMIND; ED JONES/AFP/GETTY IMAGES; TOP: FROM illnesses. The study is also significant because it we know where to look.”

January/February 2017 DISCOVER 37 2016 38 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 3 CASE WESTERN RESERVE UNIVERSITY RESERVE WESTERN CASE philosophy and bioethics of professor Associate Insoo Hyun Q & A 1 OF LIFE IN LAB THE LIMITS THE PUSHING how thesetwopapersarefueling thedebate. Western ReserveUniversityinOhiowho isnotinvolvedintheresearch,explains Insoo Hyun,anassociateprofessor ofbioethicsandphilosophyfromCase repercussions. Theteams’findings, publishedinMay, raiseda slew ofquestions. they weredestroyedjustbefore thetwo-weekmarktoavoidethicalandlegal would haveenabledlabembryostosurpassthat14-dayhurdle —though survive onlyaboutaweek—untilnow. push pastthatmarker, itcouldn’t. Culturingtechnology couldgetembryosto guideline. Butthelimithaslongbeenamootpoint:Evenif ateamwantedto the lab.Insomeplaces,likeEngland,thisisalegallimit. theU.S.,thisisjusta FOURTEEN DAYS. Two teams,oneBritishandAmerican,developedtechniquesthat

That’s how long expertscanstudyhumanembryosgrownin

 LACY SCHLEY  LACY

ROGER MASTROIANNI ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 32 ■ ■ ■ ■ ■ ■ ■ Disrupting ■ ■ ■ ■ Dopamine ■ ■ ■ ■ ■ Dogma ■ ■ ■ NEUROSCIENTISTS MAY WANT to re-examine ■ ■ what they thought they knew about ■ dopamine. The brain uses the chemical to ■ ■ communicate between cells, and dopamine ■ Ethics aside for a moment, what’s so ■ signals different events depending on ■ Q important about these findings? ■ its location. It’s required for both major ■ functions of the striatum, an area of the brain ■ This is the first time we’ve seen you can culture ■ involved in movement and reward. ■ A human embryos to the implantation stage [at ■ For a long time, scientists believed the ■ roughly seven days] and beyond. What’s important ■ about the implantation stage is that it tends to be same dopamine-releasing cells managed ■ ■ a point in human development that we understand both behaviors. But in July, researchers ■ very little about. This is precisely the stage at which at Northwestern University published a study ■ ■ the embryo begins to form specialized cells and in Nature that turned this model on its head. ■ ■ a very basic body plan. It’s also [when] a lot of Northwestern neuroscientist Daniel ■ pregnancies fail. ■ Dombeck and his team observed dopamine- ■ releasing neurons firing when mice received ■ ■ rewards and when they were moving. They ■ What does this mean for the traditional ■ time limit, then? found that neurons typically fired during one ■ Q ■ event or the other, but not both. “For the most ■ part,” Dombeck says, “they were completely ■ It presents a policy challenge for countries that ■ separate populations.” ■ A have the 14-day limit in law and in guidelines to ■ reconsider whether to extend it. But also, in countries The discovery of two cell groups, each with ■ ■ where there isn’t clear guidance, this could push a different job, could impact diseases where ■ them to decide whether they want to come up with ■ dopamine is a key player, like Parkinson’s ■ their own country-specific guidelines or laws that disease or addiction. Because, as Dombeck ■ ■ might enable researchers to go past this 14-day point. points out, “knowing there are separate ■ ■ populations of neurons tells you that you should ■ be applying treatments in a much more targeted ■ How can scientists, and policymakers ■ way than we are right now.”  MALLORY LOCKLEAR ■ Q for that matter, approach such an ethically ■ delicate decision? ■ ■ ■ ■ If scientists come forward with some compelling ■ ■ A plans for what they could study and how that ■ information might help people, it would have to be ■ ■ a constant back-and-forth discussion between the ■ scientific community and the policy regulators of Dopamine ■ molecule ■ what can be practically enforced. . . . The question ■ ■ is, after 14 days, is there another practical boundary ■ ■ LAGUNA DESIGN/SCIENCE SOURCE LAGUNA that resets the line?

January/February 2017 DISCOVER 39 2016 40 YEAR IN SCIENCE

w DISCOVERMAGAZINE.COM bigger thanJupiter. an ultracooldwarfbarely to thesamestar, TRAPPIST-1, blow. Allorbitstartlinglyclose Earth-sized planetsinone astronomers addedthree that. Meanwhile,Belgian these targetscanhelpwith tested, however.” Hehopes “This isatheorythatmustbe study authorStephenKane. water isprevalent,” says planet formationwhere a naturalconsequenceof surface water. “Lifeisprobably planets thatmighthaveliquid find some200ofalltypes telescope’s entire catalogto astronomers analyzedthe likely rocky worlds,andother scientists addedmore than100 confirmed in2016.Kepler new Earth-sizedplanetswere the headlines,butahostof Centauri b—snagged neighbor —Proxima Our nearest NEW: 130 TOTAL: 219 (0.7 to1.2R EARTH (1.2 to1.9R SUPER-EARTH night side. hotter thanthe Fahrenheit 2,000 degrees temperatures along with sun-facing side, permanently lava onits likely hasflowing nearby super-Earth, Cancri e,arelatively in March showed55 Telescope published NASA’s SpitzerSpace Observations from behemoth worlds. like amisnomerforthese “Earth” looksincreasingly NEW: 409 TOTAL: 728

E E ) ) (0.5 to0.7R MARS suggests thatmanymore are lurkingunseen. tiny exoplanets,butdiscoveringeven ahandful Technology isn’t advancedenoughtoreveal many NEW: 9 TOTAL: 17 worlds are emerging,providing newhopeforlifeinthecosmos. behemoths, butmostexcitingisthatmore Earth-sizedandothersmallish confirmed numberto2,591.Thoseplanetsrangefrom thetinytotrue worlds totheexoplanetzooin2016,bringinginstrument’s total A NEWLOOKAT DATA from NASA’s Keplerspacetelescopeadded1,284 PLANETS OF THE MILKY WAY OFTHEMILKY PLANETS (13.7 to22R SUPER-JUPITER NEW: 11 TOTAL: 142

E ) E )

(8.3 to13.7R JUPITER NEW: 39TOTAL: 203 (5.1 to8.3R MINI-JUPITER NEW: 43 TOTAL: 86 E )

E ) 1 Earthradius (R comparing exoplanetsizes is usedasabaselinewhen understand allicegiants. What are theymadeof? and/or Uranustobetter Humanity sawNeptune abundance ofNeptune- One ofKepler’s biggest designs foradedicated these icegiantsremain briefly, duringVoyager 2’s 1989flyby. In2016, surprises hasbeenthe and Uranusjustonce, pushed forward with a NASA-fundedteam shrouded inmystery. NEW: 504TOTAL: 917 NEW: 139 TOTAL: 279 How didtheyform? sized planetsacross our galaxy. Andyet mission toNeptune MINI-NEPTUNE water markedthe exoplanet roster’s gas, ice,rock and counted inthese biggest addition mini-Neptune,

(1.9 to3.1R These ballsof (3.1 to5.1R  ERIC BETZ  ERIC system’s own theoretically astronomers Planet Nine, in 2016.Not which some NEPTUNE newcomers suspect isa is thesolar predicted. only been E potential ) but has E E ) )

ALISON MACKEY/DISCOVER. PLANETS LARGE TO SMALL: NASA/GSFC/S. WIESSINGER; NASA/ESA/M. KORNMESSER; NASA/GSFC/S. WIESSINGER; NASA/JPL; NASA/ESA/A. FEILD/G. BACON (STSCI); NASA AMES/JPL-CALTECH/T. PYLE; NASA AMES/JPL-CALTECH; SETI INSTITUTE/DANIELLE FUTSELAAR ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 34 ■ ■ Superbug Arrives in the U.S. ■ ■ ■ ONE OF HEALTH OFFICIALS’ biggest fears has come ■ ■ to pass. Bacteria resistant to a medicine considered ■ ■ the last defense against superbugs has been found ■ ■ in countries around the world. And in May, it officially ■ arrived in the United States when a Pennsylvania ■ ■ woman tested positive for it. ■ ■ The woman was infected with a strain of E. coli that ■ ■ wards off many antibiotics, including colistin, which ■ is considered a last-resort drug. Since her diagnosis, ■ ■ other Americans, as well as U.S. farm animals, have ■ ■ been infected with the bug. ■ ■ The E. coli strain is a superbug in part because of ■ ■ a gene called mcr-1, which, besides shielding the strain ■ from most antibiotic medications, can travel on a piece ■ ■ of DNA. According to the Centers for Disease Control ■ ■ and Prevention, it’s then shared among other bacteria. ■ ■ The gene’s mobility enables the strain to spread easily ■ among humans and animals. Two petri dish culture plates show the interaction of bacteria ■ and antibiotics (on disks). On the left plate, bacteria around the ■ Without effective antibiotics, even minor infections ■ antibiotic disks fail to grow. But on the right plate, resistant bacteria ■ can be deadly in some people. Conditions like have no problem growing, despite the presence of antibiotics. ■ ■ pneumonia and urinary tract infections might be ■ difficult to treat. Lance Price, director of the Antibiotic Resistance ■ ■ “The danger is that we are one step closer to having Action Center and a professor at George Washington ■ ■ bacteria that are untreatable with antibiotics,” says University.  MARK BARNA ■ ■ ■ ■ ■ ■ ■ ■ 35 ■ ■ Mathematicians Find the Answers ■ ■ IN HIGH SCHOOL, ■ American whopping 28 solutions before its complete ■ students encounter a kind of wormhole set of solutions could be known, way ■ ■ connecting geometry and algebra: more than anyone expected. This created ■ Geometric objects like circles and ellipses a renewed interest in the subject — might ■ ■ are linked to algebraic equations like some curves require 50, or 500 or 5 billion ■ 2 2 ■ x + y = 1. Students can visualize all the solutions? Was there any limit at all? ■ solutions to the equation as points in the It turns out the 28-solution monster ■ 2 3 2 3 ■ circle — that is, each point in the curve y = x - x y = x - x = 1 from 2006 is a rarity. A new model ■ ■ represents a solution. Certain algebraic equations can generate published in February found that 21 ■ Make the equations slightly more elliptic curves, useful in cryptography. solutions will almost always suffice, based ■ ■ complex, and instead of circles you get on a statistical approach that simulates ■ swooping loops and lines called elliptic a trick for this: If they know a certain the behavior of elliptic curves. Yes, a few ■ ■ curves. These curves have proven useful number of an equation’s solutions, they exceptional equations require 28 or more, ■ ■ in creating cryptographic codes — and can use that wormhole between equation but not many. ■ they have beguiled mathematicians with and curve to discover the rest of the So far, the researchers have only ■ ■ their complexity and beauty. equation’s solutions. The key is knowing produced a probabilistic argument, ■ Each of those more complicated, exactly how many solutions are needed to not a definitive proof. But already, the ■ ■ curvy equations, however, has many unlock the rest. argument and its novel approach have led ■ ■ solutions, and they can be wickedly A decade ago, a mathematician to a blossoming of new ideas in the field. ■ ■ TOP: JAMES GATHANY/CDC. BOTTOM: AFTER YASSINE MRABET/CREATIVE COMMONS 3.0 MRABET/CREATIVE YASSINE AFTER BOTTOM: JAMES GATHANY/CDC. TOP: hard to find. Mathematicians developed found one elliptic curve that required a  JULIE REHMEYER

January/February 2017 DISCOVER 41 2016 42 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 36 really long.That’s somethingwe frequencies becausethecochleawas “We know theearcouldpickuplow to thebig We thought that weapon was exclusive tuned topickinguplow frequencies. from theMiddle Cretaceous. euotica link isthehorse-sized colleagues, we now know that missing published inMarch by Brusatte and Uzbekistan, fossils from thedesertsof apex predator. Thankstoananalysis of trying tosurvive andahighly evolved transition between aprimitive littlefella smaller dinosaurs. years ago from much earlier, much Tarbosaurus other gianttyrannosaurids, suchas he helpedanswer. long-running questionthat, inMarch, paleontologist StephenBrusatte. It’s a Edinburgh marvels University of such aspectacularanimallike “HOW DOESEVOLUTIONMAKE “It hadabigbrain, andanearwell- The bigmystery was thecrucial We’ve known that . It’s theonly known tyrannosaur T. rex T. , evolved about 80million arsenal,” says Brusatte. T. rex T. Timurlengia Smarts First, SizeSecond T. rex T. and and T. rex T.

?” Evolution: into.” you didn’t want torun sure itwas anastycreature tyrannosaurs. We’re also smell, like thelarger, later that ithadagreat senseof speed andagility, andwe canguess chain. We know for anopportunitytoriseupthefood pre-adapted theirsuperpowers, waiting second:“ first andsize proves thesedinosevolved smarts area. supersense.” It’s akindof that are biggerthantheyare over awide typically seeinpredators huntingthings According toBrusatte,  GEMMA TARLACH Timurlengia Timurlengia Timurlengia relied on

TURKMENISTAN Dzharakuduk species andapexpredators. a bridgebetweensmall,primitive horse-sized Asian nationofUzbekistan, Kyzylkum DesertoftheCentral Found inDzharakuduk,the species (inwhite). closely related tyrannosaurid in red) withbonesfrom other, its fragmentaryfossils(shown Timurlengia Researchers reconstructed from 90millionyearsago. transitional tyrannosaurid Timurlengia euotica 1 ft UZBEKISTAN Timurlengia AFGHANISTAN KAZAKHSTAN bycombining TAJIKISTAN is is a

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DISCOVERMAGAZINE.COM 37 close scrutiny. crumbled after her networth on paper, but billionaire a SiliconValley Holmes was Elizabeth OF THERANOS OF AND FALL RISE THE ESSAY ELIZABETH HOLMES’BIO caveat, usuallyglossed at $4.5billion.Theonly valued hernetworth turned 31, less than$10. a labappointment,andoftenfor be testedwithoutadoctor’s visitor and evencancer. Consumerscould herpes, highcholesterol,hepatitis conduct hundredsoftests—for blood, Theranosclaimeditcould no needlesandjustafewdropsof to revolutionizemedicine.Using started acompanythatpromised Holmes quitStanfordUniversityand for thelone,cleverpioneer. At19, catnip tothetechsector’s reverence over inmediaaccounts, By thetimeHolmes was thather owning oroperatinga “disruptive technology” been submittedfor had never even barredHolmesfrom Holmes saidshewas scientific peerreview. Forbes kept rolling—rightoff and theTheranostrain protecting tradesecrets, the rails. story publishedbythe July, federalregulators Wall StreetJournal late 2015triggered reign asatechsector ended Holmes’brief investigation that a government leader. Theranos ever getthechance.In possible itmightnot An investigative recent sanctions,it’s has yettoshowits works, andgiven technology actually “breakthrough”

right offtherails. kept rolling— Theranos train secrets, andthe protecting trade she was Holmes said

was in for awidevarietyoftests. only asmallvialofbloodwasnecessary Theranos’ breakthrough premise wasthat might shyawaybecauseofthis.” And I’dhatetothinkthatinvestors peer review, workinginthisfield. are goodscientists,whosubmit to away, isrealizable,”shesays. “There office, andstarttreatmentright before theyeverleaveadoctor’s in whichconsumerscangetaresult discussion. “Point-of-caretesting, something wasmissingfromthe Technologies inCancerCare,thinks directs theCenterforFuture to comefirst.” review isessential,”hesays.“It’s got scientific methodhastowin.“Peer people’s livesareatstake.” who canbehurtphysically. And world, whereyouhavecustomers type applications,versusthebio-med computers andengineering-level and workedmiracleswiththingslike Valley techculturethathasthrived at Stanford.“Thestart-upSilicon  STEVE VOLK  STEVE But CatherineKlapperich,who In thisclash,saysIoannidis,the researcher andpolicyexpert John Ioannidis,ahealth clash ofcultures,”says place? “Therewasa rise sohighinthefirst such ashakyfoundation nothing. now putshernetworthat lab fortwoyears. How didacompanywith Forbes

TOP: DREW KELLY. BOTTOM: MATHEW SCOTT ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 3 ■ 8 A Sharp Find ■ ■ ■ A POINTY BIT OF DANISH HISTORY surfaced in ■ ■ September. While combing a field in Svebølle with a metal ■ ■ detector, two amateur archaeologists heard pings and ■ started digging. Less than a foot down, they unearthed a ■ ■ 32-inch sword with a blade that was still sharp. Arches and ■ ■ recessed lines decorate the sword’s handle. The ornamental ■ ■ style suggests it’s about 3,000 years old, placing it in the late ■ Nordic Bronze Age, says Arne Hedegaard Andersen of the ■ ■ Vestsjaelland Museum in Denmark. Given that timestamp, Amateur archaeologists found an ancient sword buried in ■ Denmark (below). The fine detail of the still-sharp weapon ■ it’s possible an ancient warrior wielded this remarkably (above) survived roughly 3,000 years in the ground. ■ ■  MARK BARNA preserved relic, Andersen says. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 39 ■ Plenty of Room at the Bottom ■ ■ ■ THE LIBRARY OF CONGRESS scanning gaps between atoms and the that its reading and writing speed ■ ■ sprawls over 2 million square feet and microscope’s probe. must increase exponentially to become ■ can hold some 10 million books. In July, So far, Otte has used the technology practical. In the long run, however, he ■ ■ Delft University physicist Sander Otte to store text by Charles Darwin — and believes our existing technology won’t ■ ■ showed off a way to fit all that writing overwritten Darwin with an excerpt be able to get smaller forever. Atom ■ in a space smaller than a dust mote. from physicist Richard Feynman’s text wrangling could overcome the limitations ■ ■ Otte stores information by “There’s Plenty of Room at the Bottom.” of downscaling. “What we do completely ■ manipulating individual chlorine The storage density of this 100 breaks with that tradition,” he says. “We ■ ■ atoms within a layer of chlorine on a square-nanometer system is 500 times build new things from the bottom up.” ■  JONATHON KEATS ■ copper lattice. The chlorine is moved more compact than the most advanced ■ with the tip of an electron microscope, commercial hard disk. But the storage ■ ■ representing one computer bit with a space on this early device is still ■ Each missing atom (dark blue) in this single displaced atom. Data is read by extremely limited, and Otte admits ■ memory device holds a bit of data, ■ giving unprecedented storage density. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ TOP: MUSEUM VESTSJÆLLAND (2). BOTTOM: COURTESY OF SANDER OTTE COURTESY BOTTOM: VESTSJÆLLAND (2). MUSEUM TOP:

45 2016 46 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM of asaltyocean. be sittingontop famed heart,could part ofPluto’s Sputnik Planum, The impactcrater Pluto’s Hidden Ocean Ocean Hidden Pluto’s long: Plutomay becracking apart asits leaving too asodacaninthefreezer of IT’S THESOLARSYSTEMEQUIVALENT skin, but it’s more likely that adeepocean icelurks beneath normal Pluto’smade of saw. Theysay it’s possible ashallower ocean Pluto’s surfaceinways New Horizons never ice that would contract andbuckle sion of frozen globalseawould form anexotic ver- Pluto’s afully surface, orthepressure of that itcan’t bemore than160milesbeneath frozen? Hammondandhiscolleagues found How biganoceanare we talking, andhow Letters, onPluto’s potentialwatery insides. published inJuly inGeophysical Research watery insidesslowly freeze. at Brown University, spearheadedastudy, Ever sincetheNew Horizonsprobe Noah Hammond,agraduate student ocean underneath. buzzed PlutoinJuly 2015,scientists have beenporingover theslow suspect thecauseisafreezing as Pluto’s surfaceis, researchers high-resolution trickle of Pluto’s outershell.Andasicy images anddata tominethe that somethingisrippingapart planet’sdwarf secrets. Pluto more thanamiledeephint is more active thanscientists hundreds of mileslongand hundreds of even icevolcanoes. Fissures chains, roving glaciersand dreamed, withmountain Hammond’s deeperocean. extremely saltywater — anupwelling from underground basinitexcavated with filled when thecrater-forming asteroid hit,the found themostplausible explanation isthat than surrounding areas. Johnson’s team — astrong hintSputnikPlanum isheavier region always facesPluto’s moon,Charon tilted over theeons, leaningsothat the sittingover awateryof jackpot.Plutohas world’s famous“heart”)alsoshows signs the crater calledSputnikPlanum (partof in thesamejournalthat anancientimpact also at Brown, andcolleagues published churning withactivity. is stillfreezing, which keeps Pluto’s surface signaling that the dwarf planet has expanded. signaling thatthedwarfplanethasexpanded. at SputnikPlanum’s edgeandalineoffaults(below), New Horizonsimagesshowbroken terrain(above) And inSeptember, Brandon Johnson,  KOREYHAYNES

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DISCOVERMAGAZINE.COM 41 lunar phases. Theteam,whose research appeared in gravitational unison,ashappens duringthose when thesunandmoonare aligned andtugging occur when themoonisnearfullornew. spawned adevastating tsunami—are more likely to Chile’s 2010disaster, orJapan’s 2011quake that Tokyo discovered that larger earthquakes —like Researchers theUniversity of ledby Satoshi Ideof might indeedbearesponse tothemoon’s pull. eccentricities, itturnsoutthat someearthquakes humans are probably stilltoblame for ourown strange happenings andillfortunes.omens of While FULL MOONSANDNEW That’s becauseEarthisunderadditional stress earthquakes. be enoughtoinfluence study showsitmight and moonalign.Anew stress whenthesun Our planetfeelsmore MOON ANDSUN THE GRIPOF Bad Moon Rising Moon Bad ulmo Newmoon Full moon have longbeen Gravitational pull Earth happening any given day orweek.” that’s anearthquake stillonly a2percent chanceof 100 or1,000timesmore dangerous thanusual,but accurately. “Maybe we cansay [agiven area is]10, scientists like himunderstand thebigpicture more bullet for predicting earthquakes, but itmay help Washington, saysof thefind won’t be a silver cause theground tostartshaking. complicated whole-Earth system.Many factorscan extra pressure. Buttheseare stilltiny effects onthe and more likely toslipandstartmoving underthe that thebiggestfaultlinesare mostvulnerable, in John Vidale, aseismologist at theUniversity Nature Geoscience inSeptember, alsofound  KOREYHAYNES Sun

SDECORET/SHUTTERSTOCK. INSET: DAN BISHOP/DISCOVER ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Birds Sleep During ■ ■ 43 ■ ■ Flights, Too ■ ■ Neural fetal cells from a Parkinson’s patient ■ SLEEPWALKING CAN BE A PROBLEM, BUT SLEEPFLYING? ■ retained healthy dopamine production ■ capabilities 24 years after transplant. That’s a nifty adaptation, confirmed in August for the first ■ ■ time in birds. ■ ■ The idea that birds snooze during multiday flights has ■ 42 been floating around for decades, but only recently could ■ ■ researchers prove it. Scientists built miniature devices to ■ ■ measure avian head movement, brain electrical activity and ■ Parkinson’s ■ GPS location, and they attached them — almost like hats and ■ ■ Treatment Lasts backpacks — to great frigatebirds of the Galapagos Islands ■ in Ecuador. The large birds then flew continuously over the ■ ■ 24 Years Pacific Ocean for up to 10 days and 1,800 miles. ■ ■ The results, published in Nature Communications, showed ■ ■ A TREATMENT for Parkinson’s has that frigatebirds could soar and glide with one or both sides ■ lasted more than two decades, a medical ■ ■ first, according to researchers from Lund ■ ■ University in Sweden. ■ Back in the 1980s and ’90s, researchers ■ ■ took neural cells from human fetuses ■ and inserted them into the brains of ■ ■ 10 people diagnosed with Parkinson’s, ■ ■

RMISSION FROM MACMILLAN PUBLISHERS LTD: BRYSON VOIRIN/NATURE COMMUNICATIONS/10.1038/NCOMMS12468/3 AUGUST 2016 AUGUST COMMUNICATIONS/10.1038/NCOMMS12468/3 VOIRIN/NATURE BRYSON PUBLISHERS LTD: RMISSION FROM MACMILLAN a neurodegenerative condition. They ■ hoped the healthy fetal cells would restore ■ ■ diminished brain function. The patients ■ ■ were monitored until death. Then tissue ■ samples were collected from brain areas ■ ■ where healthy neurons had been introduced. ■ In a June paper in the Proceedings of ■ ■ the National Academy of Sciences, the ■ ■ Lund team described the brain of a patient ■ who’d received a unilateral transplant — ■ ■ where only one side of the brain received ■ the treatment — 24 years earlier. After ■ ■ all that time, nearly 90 percent of the ■ ■ donor cells remained healthy and fully ■ functioning, an unprecedented amount. ■ ■ “We were just so excited to see that so ■ Scientists monitored the head movements and brain activity of flying frigatebirds, ■ many transplanted cells still survived,” says confirming for the first time that the birds could sleep midflight. ■ co-author Jia-Yi Li. ■ ■ While roughly 10 percent of the of their brains asleep. What’s most surprising is not that ■ transplanted cells did carry the proteins ■ the birds could sleep while flying, but how little they did: an ■ that make up Lewy bodies, a hallmark of average of 42 minutes a day in flight, compared with 12 hours ■ Parkinson’s, the silver lining is Li and his ■ a day on land, according to neuroscientist Niels Rattenborg ■ team will get a better look at how those ■ of Germany’s Max Planck Institute for Ornithology. ■ proteins spread. Overall, he says, this ■ double-decade success “gives us a very “That’s a level of performance on little sleep that we can’t ■ ■ positive and very bright future for stem match,” says Rattenborg. Determining how frigatebirds ■ ■ cell transplantation therapy in Parkinson’s function with so few Zs could help researchers better ■  BRIDGET ALEX ■ TOP: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES/WEN LI ET AL./10.1073/PNAS.1605245113/7 JUNE 2016. BOTTOM: REPRINTED BY PE BOTTOM: JUNE 2016. AL./10.1073/PNAS.1605245113/7 OF SCIENCES/WEN LI ET ACADEMY THE NATIONAL PROCEEDINGS OF TOP: disease.”  LACY SCHLEY understand and combat sleep loss in humans.

January/February 2017 DISCOVER 49 2016 50 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 44 NEW SPECIES

We noticed a theme in several of the species new to science this year: They landed in the spotlight ready to rumble, with more tricks up their sleeves (if they had sleeves) than a pro-wrestling heel. While these new species will never meet in real life, we can imagine how things might go down if they did.

BY GEMMA TARLACH ILLUSTRATION BY DANIEL GOLDFARB

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Named for the Man in Black, this tarantula can this tarantula Named for the Man in Black, £ ■ be found near Folsom Prison and probably would Prison and probably be found near Folsom APHONOPELMA JOHNNYCASHI The namesake of the The namesake ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■

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The alpine viper hiding in plain sight — with a ■ ■ ■ ■ ■ DANIEL GOLDFARB/RICHARD SOLOMON ARTISTS REPRESENTATIVE ARTISTS SOLOMON GOLDFARB/RICHARD DANIEL

January/February 2017 DISCOVER 51 2016 52 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 45 46 computing or the Internet of Things, where companies computing ortheInternetof workhorse systemsmay notbethe bestfit for cloud the early ’90s. Butdevices are changing,andthose first built in1969.Android usesLinux, developed in originated decadesago. Apple’s OSisbasedonUnix, Joshua Cruz. all related toAndroid orChrome OS,” says Google rep it. “Fuchsiaisanew open-source project that isnotat the company hasbeenmum about how itplans to use The OSisanopen-source project calledFuchsia,and quietly unveiled anoperating systembuilt from scratch. It’s stillthecore ofmanyoperatingsystems. Ken Thompson(seated)andDennis Ritchiecreated Unixin1969. IN AUGUST, GOOGLE fired a beam of the atoms at atarget fired abeamof strong) withfour extra neutrons, and two protons andtwo neutrons produced heliumatoms (normally might exist. To findout,physicists debated whether suchastrange atom Factory inJapan. at theRadioactive IsotopeBeam Tomohiro Uesaka,who ledthework it has, thisis“elementzero,” jokes is classified by how many protons thought impossible. Becausematter neutrons —somethingmany only of anatom made revealed evidence of IN FEBRUARY, PHYSICISTS The operating systemsthat drive moderncomputers Since the’60s, scientistshave Nothin’ But Neutrons But Nothin’ Google Builds Operating System From Scratch System BuildsOperating Google set rumormillsspinningwhen it neutrons, asillustratedhere. produced anatommade uponlyoffour Physicists sawevidencethatthey’d better operating system designs,” hesays. promising. “It could startshiftingtheculture sowe see that from aresearch perspective, Google’s play looks making itmore reliable and information inthecore,that theamount of minimizes attack.” Fuchsiarunsonamicrokernel calledMagenta Titanic: in operating systemssecurity. Helikens themtothe Pennsylvania’sof Nathan Dautenhahn,anexpert which leaves themvulnerable, says theUniversity and hardware. Agingkernels tendtobebehemoths, an operating systemthat interfacesbetween software Google alsobuilt anew kernel —thecentral part of scientist Peter Dinda. University computer says Northwestern OS structures,” in exploring other interest again of seeing anexplosion a result, “we’re now to streetlamps. As from refrigerators to everyday devices add connectivity To runFuchsia, “They’re large andbrittlesusceptible to tightly. stars, canpackmatter together so certainlarge dense remains of how neutron stars, theincredibly theuniverse: a larger mystery of briefly boundthemcould explain together. Theunknown forces that better understandwhat holdsthem these strange atoms’ existence and designing experiments tosolidify asecond. fraction of neutrons hadclustered together for a fourand calculated that groups of what cameflyingouttheotherside liquidhelium.Theymeasured of Currently, Uesaka’s teamis between software andhardware. an operatingsystem,interfacing areKernels thecentralpartof  SHANNON PALUS SHANNON P Memory CPU secure. Dautenhahnsays Application Kernel  STEPHEN ORNES  STEPHEN Devices

FROM TOP: APS/ALAN STONEBRAKER; DAN BISHOP/DISCOVER AFTER KERNEL_LAYOUT VIA WIKIMEDIA COMMONS; COURTESY OF NOKIA BELL LABS ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 47 ■ ■ Spark of Life ■ ■ ■ ■ FOR POTENTIAL PARENTS but evaluating eggs has ■ ■ struggling with fertility, bright always been much less ■ eggs might be good eggs. straightforward. Now, thanks ■ ■ Scientists at Northwestern to these flashes, that task ■ ■ University announced in April could get a lot easier. ■ ■ that they had recorded flashes The sparks are associated ■ of light from human eggs that with eggs expelling the mineral ■ ■ may be an indicator of egg zinc after they’re injected with ■ ■ quality. spermlike enzymes. (Federal ■ ■ Fertility clinics can identify law prohibits researchers from ■ ■ healthy human sperm based on fertilizing eggs with actual ■ their movement and structure, sperm.) The flashes, which ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ NORTHWESTERN UNIVERSITY/SCIENTIFIC REPORTS/10.1038/SREP24737/26 APRIL 2016 UNIVERSITY/SCIENTIFIC REPORTS/10.1038/SREP24737/26 NORTHWESTERN ■ ■ ■ ■ ■ ■ ■ ■ ■ appear as a halo around each ■ ■ egg, happen a few minutes after ■ ■ fertilization. ■ Previous mouse experiments ■ ■ demonstrated that these flashes ■ ■ were more intense for higher- ■ ■ quality fertilized eggs. If ■ these “fertility fireworks” are ■ ■ also indicative of egg quality ■ ■ in humans — a question the ■ ■ Northwestern team intends ■ ■ to investigate — doctors could ■ non-invasively select the best ■ ■ eggs for in vitro fertilization. ■ ■  KATHERINE KORNEI ■ ■ ■ ■ Flagging viable sperm (above) is easier ■ than spotting healthy eggs. Now, ■ ■ researchers can see which human eggs ■ are healthiest by their release of zinc, ■ shown in halolike bursts in timelapse ■ ■ TOP: DON W. FAWCETT/SCIENCE SOURCE. BOTTOM: REPRINTED BY PERMISSION FROM MACMILLAN PUBLISHERS LTD: WOODRUFF, O’HALLORAN ET AL., O’HALLORAN ET WOODRUFF, PUBLISHERS LTD: REPRINTED BY PERMISSION FROM MACMILLAN BOTTOM: SOURCE. FAWCETT/SCIENCE W. DON TOP: images (left), at fertilization.

January/February 2017 DISCOVER 53 2016 54 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM Ossendrijver spottedinastack previously unstudiedtablet that in surprisingly modernways. that theBabylonians were thinking a January Berlin, finally solved the mystery in historian at HumboldtUniversity in to trapezoids. several make baffling references Almost allusearithmetic,but tablets, which stillsurvive. many of instructional texts oncuneiform astrology, Babylonian priestswrote fluctuations. Intheserviceof reveal weather patterns andmarket planetary motionwas thoughtto IN ANCIENTBABYLON, The insightcamefrom a Mathieu Ossendrijver, ascience Science paper. Hefound

with thechart’s vertical axes, that downward-slanting line. Combined 60 days, itsslowdown forms a apparent velocity inthesky over with Jupiter? Chartingtheplanet’s geometric tablets. matched thoseontheperplexing distance traveled by theplanet— clay —which calculate thetotal The numbers inscribedinthe sky asitappears toslow down. the planet’s motionacross thenight arithmetical techniquetopredict Jupiter,mention of showing an Museum. Thetablet makes explicit oldphotosfrom theBritish of 48 So what dotrapezoids have todo Jupiter Tracked Tablets Babylonian a 60days Jupiter travelsequalsthearea oftheshape. recently figured out.Theobserveddistance scientistsonly trapezoids, onewhichmodern relationship betweenJupiter’s motionand Ancient Babylonianpriestsdivineda 0 day market prediction. and valuable tools inweather and modernscience graphs, pillarsof integral calculusandtheuseof the techniqueanticipates both other ancientculture.” Infact, comparable hasbeenfound inany says Ossendrijver. “Nothing abstract mathematical space,” “deal withfigures inamore land, but thesecomputations used geometrytopartition special for Babylonians, who the distanceJupiter hastraveled. The trapezoid’s area then equals makes aright-angledtrapezoid.

Calculating area was nothing Jupiter's velocity Jupiter's  JONATHONKEATS

FROM LEFT: NASA/ESA/A. SIMON (GODDARD SPACE FLIGHT CENTER); TRUSTEES OF THE BRITISH MUSEUM/MATHIEU OSSENDRIJVER (2) ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Redefining the ■ ■ ■ 50 ■ Brain’s Divisions ■ ■ ■ ■ ■ ■ ■ ■ Sensory/Motor ■ (Green) ■ ■ 49 ■ ■ ■ ■ ■ ■ See How ■ ■ ■ They See ■ Visual ■ Auditory (Blue) ■ THOSE THREE BLIND MICE from ■ (Red) ■ the nursery rhyme might have a chance ■ to see the farmer’s wife coming after all. ■ ■ For the first time, vision has been ■ partially restored in blinded mice. The ■ ■ feat raises hopes that similar techniques ■ ■ might restore nerve-cell function not ■ only in the human eye, but also in ■ SURPRISE, SURPRISE: There’s a new map of the brain, just like ■ the spine and brain. every other year. But this time, it’s the most comprehensive guide ■ The study coupled gene therapy that ■ to the human cortex — the brain’s outermost layer, responsible ■ OSTON/WASHINGTON UNIVERSITY SCHOOL OF MEDICINE OSTON/WASHINGTON excited visual neurons in the eyes with ■ for things like complex thought, creativity and language. ■ stimulation — a swirling black-and- ■ white grid placed in front of the mice. Most maps, like the still-popular Brodmann’s map from 1909, ■ ■ The combination prompted the regrowth are based on just one ■ property, such as the ■ of axons — the “telephone wires” that ■ help neurons communicate — projecting cells’ arrangement. ■ ■ from retinal ganglion cells (RGCs). But the new work, ■ These cells line the eye’s inner surface, ■ published in Nature in ■ sending visual information to the brain. August, incorporates ■ Some RGC axons grew all the way back ■ over 100 properties, ■ to the brain’s visual-processing areas. ■ such as the cortex’s ■ And investigators could tell from the thickness, its wiring ■ mice’s behavior that their vision had ■ ■ returned, even if not perfectly. and activity during ■ various tasks. ■ The study, published in Nature ■ Neuroscience in August, builds on recent Using scans from David Van Essen (left) and Matthew Glasser ■ (right) were part of the team that mapped the ■ research where neuroscientists got RGC hundreds of people, human cerebral cortex, shown at top, in more ■ ■ axons to regrow only slightly. This is the the researchers detail than ever before. ■ first time the regenerated cells have made confirmed 83 known ■ ■ it back to the central nervous system, functional regions and outlined 97 new ones — either by further ■ says John Dowling, a Harvard University ■ partitioning known areas or recognizing overlooked areas. ■ neuroscientist not involved in the work. By subdividing the brain more strategically, the map can ■ “We’re inspiring these neurons, ■ help pinpoint particular sections’ functions and help determine ■ in the molecular sense, to navigate ■ how different cortical regions contribute to development, aging ■ their way back to their correct location ■ in the brain,” says Andrew Huberman, and disease. Plus, it can be improved with new information, ■ ■ the Stanford University neurobiologist says Washington University neuroscientist Matthew Glasser, ■ ■ who led the study. “It’s like a dog that the paper’s lead author. “It’s not like Brodmann’s map, which ■ ■ CLOCKWISE FROM TOP: TATJANA RUSSITA/SHUTTERSTOCK; MATTHEW GLASSER/ERIC YOUNG/WASHINGTON UNIVERSITY SCHOOL OF MEDICINE; ROBERT B ROBERT UNIVERSITY SCHOOL OF MEDICINE; YOUNG/WASHINGTON GLASSER/ERIC MATTHEW RUSSITA/SHUTTERSTOCK; TATJANA TOP: CLOCKWISE FROM never forgets its way home.”  DAN HURLEY is set in stone and never changes or gets better.”  TEAL BURRELL

January/February 2017 DISCOVER 55 2016 56 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 51 Scientists finally moved past“problematica” — But was itaswimming snail?Anarthropod? animal that fedthrough atoothy proboscis. Monster, was abizarre 300million-year-old revealed thecreature, known astheTully Work at Chicago’s FieldMuseumeventually 1958. Andit’s puzzledscientistsever since. in discarded rocks at anIllinoiscoalpitin FRANCIS TULLY Mystery The Tully Monster including thisone(right). Illinois, northeastern fossils foundonlyin eye bar, isknownfrom proboscis anddorsal (above), withitsjointed year-old Tully monster The strange,300million- found hisfossilized monster ancient clade,” McCoy says. avery diverse,are themselves “justremnants of between theanimalsshows thejawless lamprey relative. Understandingtherelationship Tully was avertebrate andlikely lamprey them withmodernandancientanimals, finding cataloged themonster’s features andcompared graduate studentVictoria McCoy andherteam creatures defyingboundaries— in March. Yale ERIC BETZ ERIC

ILLUSTRATIONS BY SEAN MCMAHON/YALE UNIVERSITY; INSET PHOTO BY PAUL MAYER/THE FIELD MUSEUM ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 52 ■ A Quantum Machine for All . . . ■ ■ ■ QUANTUM DEVICES remain the ultimate in computing ■ ■ prowess, but after 35 years of development, only elite ■ ■ research labs have even rudimentary examples of them. ■ ■ In May, however, IBM made news with a research- ■ ■ oriented quantum machine, called the IBM Quantum ■ Experience, accessible to anyone with an internet ■ ■ connection. Scientists, students and enthusiasts can ■ ■ use it to advance business technology, industrial ■ ■ materials or medical research. The machine could ■ be an essential step toward ■ ■ widespread deployment and use ■ ■ of quantum computers. ■ ■ The potential of quantum ■ devices is the stuff of legend. ■ IBM scientist Stefan Filipp examines qubits stored in a dilution ■ Scientists yearn to simulate refrigerator. At left is a layout of the IBM 5-qubit processor. ■ ■ chemical processes and ■ ■ design highly effective machines with as many as 10 qubits. ■ pharmaceuticals, while engineers Meanwhile, quantum devices are notoriously ■ ■ see great potential for quantum tetchy. Qubits must be kept in a quantum ■ ■ algorithms to bolster machine learning and process superposition — representing both a 1 and 0 at the ■ ■ big data. The machines could easily perform a same time — during a calculation, isolated from ■ ■ massive number of calculations that would take a all electromagnetic and thermal interference. This ■ classical computer more time than the universe has requires special shielding and operating temperatures ■ ■ been in existence. approaching absolute zero, with remote access provided ■ ■ Eventually, that is. Right now, improving output by a robust network interface. ■ ■ consistency is an ongoing area of research and The Quantum Experience is the first serious attempt ■ development. And with 5 qubits — each a unit of at building the required infrastructure for the promised ■ ■ quantum information, similar to a digital bit in classical quantum computing paradise. By making the computer ■ ■ computers — IBM’s machine isn’t in the top tier of available online to anyone, IBM is learning how to make ■  JONATHON KEATS ■ quantum machines. The company works internally on the quantum quotidian. ■ ■ ■ ■ ■ ■ ■ 53 ■ . . . And One That's Fully Programmable ■ ■ ■ A SMALL BUT MIGHTY ■ quantum computer was ■ debuted in August by physicists at the University ■ ■ of Maryland. Unlike other quantum devices, ■ ■ this one is fully programmable, a significant ■ ■ step toward general use of quantum machines. ■ ■ Ions trapped by electric fields and controlled via ■ laser enable the device to run any algorithm, or ■ ■ sequential operation of steps, using 5 qubits. “This ■ ■ system was built so that it could be scaled up,” ■ ■ says physicist Chris Monroe, whose team is adding ■ qubits to the device. The scale-up has no clear ■ An ion trap captures charged particles in a quantum machine, ■  STEPHEN ORNES ■ FROM TOP: IBM RESEARCH (2); S. DEBNATH AND E. EDWARDS/JOINT QUANTUM INSTITUTE EDWARDS/JOINT QUANTUM AND E. DEBNATH S. IBM RESEARCH (2); TOP: FROM limit, he adds. helping it to run any algorithm, or sequential steps, using 5 qubits.

January/February 2017 DISCOVER 57 2016 58 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 54 of thickened — ectoderm of develop from plates specialized differently: Feathers andhair coverings were thought to grow seemed unlikely, because thebody distant shared ancestor. Butit the samebody partontheanimals’ and mammalhairevolved from whether reptile scales, bird feathers evolutionary puzzle. he never expected tosolve amajor why thelizards didn’t have scales— dragons, hejustwanted toknow started studying naked bearded biologist MichelMilinkovitch WHEN UNIVERSITYOFGENEVA he found placodesinotherreptiles, too. Milinkovitch says. Knowing where andwhen tolook, the rightplace, otherwiseyou justmissthem,” depending onthespeciesanddevelopmental stage. exist for afew hoursandappear indifferent places lizards normal he realized hisnaked dragons lizards,embryos andnormal of to develop from raised skinareas withoutplacodes. seen inreptiles. Scaleswere thought anatomical placodes, structures not embryonic celllayer called — reptile scalesdevelopedfrom placodes. they’re shownontheembryonicskinofamouse,snake, chickenandaNilecrocodile. Itwasn’t until2016thatscientistsr Each ofthesestructures, calledplacodesanddisplayed indarkblue,willgiverisetoahair, ascaleorfeather. Here (fro Biologists have longdebated “You have tolookreally at therighttime, at As Milinkovitch differences scrutinized between Evolutionary Link Link Evolutionary Skin-Deep

an an do have placodes, but they were keyinfindingalink thatexplainstheevolutionofscales,feathersandhair. Bearded dragonslikethese (bottomisnormal,top“naked”andthemiddleahybrid) finally closingthebookonthislong-standing mystery. published thesefindingsin June in nails that are deformed orjustabsent. up withmissingplacodes, orsweat glands, teethor When mutations occurthere, thevertebrates may end vertebrates —includinghumansshare thisgene. A mutated geneinvolved inplacodeformation. Other  BRIDGET ALEX  BRIDGET Milinkovitch andco-authorNicolasDi-Poï He alsodiscovered why hisdragons were naked: Science Advances m lefttoright), ealized ,

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DISCOVERMAGAZINE.COM 56 55 This year, ateamledby the Hebrew University genes, like oregg. asperm contain justonesetof cells, tissuebut which canbecomeany kindof they have longsoughthaploid embryonic stem protect against, disease. Andso how genescanleadto, or of give researchers aclearer picture in thelab. drawback for studying diseases mutant genes—andthat’s a healthy backuptooffset those Duplicate DNA canactasa DNA copiesfrom eachparent. from mutant genes thanksto insurance, protecting offspring health provides akindof SEXUAL REPRODUCTION THEY START HEARINGVOICES. schizophrenia provides astartingpoint. identifying thispotentialmolecularmechanismin emerge,” McCarroll says. . . . vulnerabilities tomany neuropsychiatric illnesses in which brain circuits changeandreorganize and the 20s. “It’s aperiodinhumandevelopment schizophrenia arisesduringthe late teensinto process destroys healthy brain tissue. when itrunsamok,asdoesinschizophrenia, the prune unnecessaryconnectionsbetween cells. But inherit thedisease. Inhealthy brains, thegenehelps agenecalledC4were more likelyvariations of to samples from deceasedpatients. schizophrenia cases, 36,000controls and700brain through geneticinformation from about 29,000 Institute, basedinCambridge, Mass., combed theBroadled by geneticistSteven McCarroll of they’ve found what helpsflipthat switch. Ateam has flippedintheirbrains. in theirheads. To schizophrenics, it’s like aswitch that aren’t there. Theythinksomeoneplantedideas Although treatments may beyears away, C4’s involvement mightalsoexplain why McCarroll found that patients who hadcertain In February, scientistsreported in Removing that backupcould Schizophrenia’s GeneticSpark Lab Divides Human Egg Cells Egg Human Divides Lab They seethings Nature  PAULSMAGLIK that cell (right)has46. whereas thediploid chromosomes, cell (left)has23 The haploid backup planfailedthem. investigating therapies for peoplewhose genetic genetic mutations causetumorstoform and be usedfor cancerresearch, which determining copy of eachgene. copy of expressed becausethere’s only one specific mutations are always haploid cell“library” inwhich team isnow assembling amutant division —about 1in1,000.The cells that stayed haploid after them, theresearchers couldisolate cells todivide. cells by forcing egg unfertilized haploid humanembryonic stem Jerusalem finally producedof These mutants willinitially By rapidly screening many of  JONATHONKEATS

TOP: ILLUSTRATION WORKS/ALAMY STOCK PHOTO. BOTTOM: GLORYN CHIA/COLUMBIA UNIVERSITY MEDICAL CENTER ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ The Tsunamis ■ ■ 57 ■ ■ ■ of Mars ■ ■ ■ SOME 3.5 BILLION YEARS ago, planet’s northern lowlands, where ■ ■ a meteor splashed into an ocean they observed the telltale signs ■ ■ on northern Mars, creating a of destruction: a washed-out ■ wall of water 400 feet high. The coastline, rocks strewn across ■ ■ tsunami crashed down — in valleys and mountains, and ■ ■ seemingly slow motion, due to the channels carved by water rushing ■ ■ low gravity — and then rushed back into the ocean. Everything ■ across hundreds of thousands matched up with simulations ■ ■ of square miles of plains and up already completed by another ■ ■ into highlands. It happened again group in 2014. ■ ■ a few million years later, except While scientists still debate ■ with a noticeably icier ocean. In a whether Mars even had an ocean ■ ■ Scientific Reports paper published at the right place and time, ■ ■ online in May, scientists said Rodriguez says that tsunamis ■ ■ they had found evidence of — rather than wind or glaciers — ■ ■ the two events. are the only explanation for these ■ The team, led by Alexis geologic features.  SHANNON PALUS ■ ■ Rodriguez of the Planetary ■ A global relief map of Mars (below) ■ Science Institute in Arizona, shows low elevations in blue, where ■ looked at snapshots taken ancient oceans likely covered much ■ of the northern hemisphere. Along ■ from three Mars orbiters. The ■ the now-dry coastline, researchers ■ researchers focused on the found evidence of tsunamis (right). ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ RELIEF MAP: MARS ORBITER LASER ALTIMETER SCIENCE TEAM/NASA. INSET: NASA/JPL/MALIN SPACE SCIENCE SYSTEMS/ASU NASA/JPL/MALIN SPACE INSET: TEAM/NASA. SCIENCE ALTIMETER MARS ORBITER LASER RELIEF MAP:

January/February 2017 DISCOVER 61 2016 62 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 58 MILLIONS OFAMERICANS in cellsignaling,calledG rafts sequesteraprotein involved that, indepressed patients, lipid molecules. Previous studiesshowed inorganizingspecializes important thecellmembrane that area of focused onlipidrafts —an examined rat brain cellsand Illinoisat Chicago,University of published inJuly offers aclue. the peculiarity, but new work Researchers couldnever explain for patients tofeelany effects. year, yet ittypically takes weeks prescribed antidepressants each antidepressant that’s thought an SSRI,acommontypeof keeping itfrom doing itsjob. The study, from researchers at The researchers administered Are SoAre Slow Why Antidepressants α S , are work shows theantidepressant low serotonin levels. Thenew to work by increasing thebrain’s which playarole inantidepressants’ delay. in acellmembrane’s lipidrafts(orange), Two protein receptors (yellow, red) float delay of antidepressants.delay of corresponded tothetherapeutic This physical delay inthecells the protein more effective. rafts, freeing itupandmaking respond toanantidepressant. help predict how patients will findings todevelop atestto He says he planstousethese for antidepressants’ lag time. more thanjustanexplanation at UIC, seesthesefindingsas thestudy andaphysiologistof G rafts, andafterward, thecritical drug firstcollectedinthelipid SSRIs, theteamsaw that the effects. When administering appears tohave otherimportant  MALLORY LOCKLEAR  MALLORY α Mark Rasenick, anauthor S protein moved out of the protein moved outof

TOP: IGORSTEVANOVIC/SHUTTERSTOCK. BOTTOM: NICOLLE R. FULLER/SCIENCE SOURCE ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ First Glance ■ ■ ■ ■ 60 ■ Into the Gut ■ ■ “GUT INSTINCT” ■ isn’t just ■ a turn of phrase — the ■ ■ ■ 59 Cyanobacteria digestive system ■ actually contains ■ ■ five times more ■ Virus Uses ■ neurons than ■ the spinal cord. ■ ■ CRISPR to Hack But how this ■ ■ so-called ■ Bacterial Immune ■ second brain ■ works has ■ System ■ remained ■ ■ VIRUSES ARE WILY predators that mysterious. ■ ■ can kill their hosts and cause lethal Now, Duke ■ human diseases. They can also hijack University researchers ■ ■ CRISPR DNA to help their host, though have created a window — ■ ■ not without an ulterior motive. literally — into this once- ■ In recent years, CRISPR, a sequence ■ hidden part of the body. ■ of DNA, has become best known for its Engineer Xiling Shen This schematic shows how researchers used a ■ use in gene editing, when scientists alter glass window and microscopic imaging to get ■ and his colleagues cut a live view of neurons in the digestive system. ■

KHILIN ET AL./NATURE COMMUNICATIONS, ADVANCE ONLINE PUBLICATION,7 JUNE 2016/DOI: 10.1038/NCOMMS11800 (2) JUNE 2016/DOI: ONLINE PUBLICATION,7 ADVANCE COMMUNICATIONS, AL./NATURE KHILIN ET or delete DNA in living organisms. It's ■ a tiny hole in a mouse’s ■ a technique that may soon revolutionize ■ therapeutics. In nature, bacteria use abdomen, affixed sensors outside the intestine to monitor both ■ ■ DNA snippets from viruses to form electrical and chemical activity, and sealed the hole with glass. ■ CRISPR sequences to fight viral Their engineering provided the first-ever live-action movie of ■ ■ infections. The DNA enables bacteria nerves lighting up in the gut. ■ ■ to recognize the viruses and destroy Getting a look at these digestive neurons, called the enteric ■ them if they attack again, thereby ■ nervous system, could provide insight into gastrointestinal ■ avoiding infection. conditions, like irritable bowel syndrome. These disorders ■ In a study published in June, Canadian ■ stymied researchers in the past, because current GI imaging can’t ■ scientists explained how the viral strain ■ see the neurological activity likely related to these problems. ■ Cyanophage N-1 similarly sought the After their work was ■ upper hand, stealing a CRISPR array of ■ published in Nature ■ DNA from bacteria that contains DNA ■ Communications in June, ■ from other viruses. The viral strain stored ■ the DNA snippets in its genome and then the group improved ■ ■ gifted them to freshwater cyanobacteria. the picture’s quality ■ This gave the cyanobacteria immunity to ■ by adding more sensors. ■ other viruses. They are also making ■ ■ The gift came at a price, though: The their technology available ■ N-1 virus could now freely multiply ■ to other groups studying ■ within its host without viral competition. diseases like IBS. What ■ Curtis Suttle, an environmental ■ started as a window into ■ microbiologist and senior author of the ■ a nervous system could ■ study in mBio, says scientists previously ■ had never seen a virus use a CRISPR become a door to better ■ ■ array in this manner. “It’s a nice understanding and ■ treatment of GI diseases, ■ evolutionary trick that we wouldn’t have Imaging of digestive neurons shows the ■  LINDA MARSA  PAUL SMAGLIK ■ CLOCKWISE FROM TOP: SCIENCE STOCK PHOTOGRAPHY/SCIENCE SOURCE; REPRINTED BY PERMISSION FROM MACMILLAN PUBLISHERS LTD; NIKOLAI RA NIKOLAI PUBLISHERS LTD; REPRINTED BY PERMISSION FROM MACMILLAN SOURCE; PHOTOGRAPHY/SCIENCE SCIENCE STOCK TOP: CLOCKWISE FROM predicted,” Suttle says. Shen says. vasculature in green and the neurons in red.

January/February 2017 DISCOVER 63 2016 64 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM a 5.8magnitude in2016. recorded: a5.7magnitude in2011and USGS, includingitstwo largest ever California, says MichaelBlanpiedof had more magnitude 3.0quakes than annually. Inrecent years, Oklahoma has tohundreds dozen from acoupleof at leastmagnitude 3.0haveof increased slip. Since2009,tremors inmid-America ground, causingfaultstoseparate and fuel extraction ispumpeddeepintothe process: Wastewater from thefossil thehydraulic fracturing due topartof has experienced anuptickinquakes shaker probability. America’s midsection Oklahoma leadingMidwestern states in alongside natural temblor hazards, with include human-inducedearthquakes annual forecast maps for thefirsttime THE U.S.GEOLOGICALSURVEY’S induced byhumanactivity. seismic hazard risksandthose Survey showsbothnatural from theU.S.Geological A compositeofnewmaps 61 Sacramento Seattle Phoenix  MARK BARNA Geological Hazard Map Geological Hazard Human Activity Shakes Up Denver associated withseismichazards, suchasOklahoma. causes faultstoseparateandslip,resulting inearthquakesstatespreviously not During hydraulicfracturing,wastewaterisinjecteddeepunderground. Theprocess Austin Lincoln City Oklahoma Dallas Minneapolis Nashville Columbus Boston Lowest chance Highest chance Damage Chance of <1% 1%–2% 2%–5% 5%–10% 10%–12%

TOP: J PAT CARTER/GETTY IMAGES. BOTTOM: GEOLOGIC HAZARDS SCIENCE CENTER/U.S. GEOLOGICAL SURVEY ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Dark peppered ■ moths (left) thrived ■ in polluted cities, but ■ lighter moths (below) ■ ■ have seen a comeback ■ 62 with cleaner air. ■ ■ ■ ■ ■ ■ Dark Wings Decoded ■ ■ ■ SCIENTISTS HAVE FINALLY ■ ■ pinpointed the genetic mutation ■ ■ that made the peppered moth ■ ■ a Biology 101 fixture. ■ When the Industrial Revolution on their target: a transposon, or ■ ■ caked British cities with soot, so-called “jumping gene,” which ■ ■ peppered moths’ light, speckled can move from one place on ■ ■ wings made them easy targets for the genome to another, causing ■ predators. As a result, a dark- mutations. The team’s models ■ The peppered moth easily camouflages ■ winged variant emerged that could revealed that the “jump” likely ■ into the bark of a birch tree near ■ hide in a carbon landscape. Within Derbyshire in the United Kingdom. occurred around 1819 — the midst ■ ■ a century, all-black moths replaced of coal-fired industrial might. ■ ■ the speckled variety. crossbred lines of black and How this mutation alters wing ■ To uncover the underlying speckled moths. Their genetic colors is still a mystery, but the ■ ■ genetics of this quintessential mapping technique identified DNA discovery helps decipher the ■ ■ example of natural selection, segments unique to black moths. nuts and bolts of evolutionary ■  CARL ENGELKING ■ University of Liverpool scientists And eventually, they converged adaptation. ■ ■ ■ ■ ■ ■ ■ ■ 63 Not Your Kid’s ADHD ■ ■ ■ ATTENTION-DEFICIT/HYPERACTIVITY DISORDER ■ ■ (ADHD) often is considered a condition that’s ■ ■ diagnosed in childhood, bringing to mind fidgety, ■ ■ impulsive youngsters. But two studies published ■ ■ in June in the Journal of the American Medical ■ ■ Association Psychiatry suggest ADHD symptoms can ■ also appear in early adulthood. ■ ■ Researchers in the two studies tested over 7,000 ■ ■ children for ADHD at various stages in childhood, ■ ■ re-examining them at age 18. Currently, diagnosis ■ requires symptoms to begin before age 12. However, ■ ■ the retests revealed that the majority of adults who met ■ ■ diagnosis criteria for ADHD (68 percent in one study ■ ■ and 87 percent in the other) did not have symptoms ignores adults starting to struggle. “The people that ■ as children. The authors hypothesize that the stress we found with late-onset ADHD were basically as ■ ■ of supporting themselves or attending college exposes impaired as those who had it as kids,” says study ■ ■ some people’s symptoms as they enter adulthood, co-author Jessica Agnew-Blais, a psychiatrist at King’s ■ ■ or that a distinct adult version of ADHD may exist. College London. “Even if you didn’t have ADHD in ■ ■ The findings challenge our understanding of the childhood, that doesn’t mean that you wouldn’t benefit ■  TEAL BURRELL ■ FROM TOP: BRISTOL CITY MUSEUM/NATURE PL.COM (2); ALEX HYDE/NATUREPL.COM; CHICAGO TRIBUNE/MCT/GETTY IMAGES TRIBUNE/MCT/GETTY CHICAGO ALEX HYDE/NATUREPL.COM; PL.COM (2); CITY MUSEUM/NATURE BRISTOL TOP: FROM disorder; the age criteria for diagnosis in place now from clinical attention in adulthood.”

January/February 2017 DISCOVER 65 2016 66 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM not uncommonforlooterstocreate forgerieson in the13thcentury, skepticsarguedthatitwas Though carbondatingplacedthemanuscript and manyarchaeologists doubteditwasauthentic. manuscript’s shadypasthasdogged iteversince, sold inthemid-1960stoaprivatecollector. The by lootersintheChiapasstateofMexicoand exhibited inthe1970s,hasbeendatedtoA.D.1257. the Grolier ClubinNewYork, where thetextwas from theAmericas.TheGrolier Codex,namedfor has beenproven tobetheoldestknownbook movements ofVenus anddecoratedwithdeities A PRE-COLUMBIANMayacalendarchartingthe The codex,orpaperbook,wasdiscovered Authenticated in the Americas Book Oldest of Venus across thesky. charted themovements decorated withdeities, 1257. TheMayacalendar, scholars havedatedtoA.D. of thecodex,which are depictedonfragments decapitating anothergod, death god(right),shown warrior (left)andtheMaya A goddressed asaToltec the sky. aspect oftheplanetVenus asitmovedthrough warrior ordeitywholikelyrepresents adifferent contains 11pages,eachfeaturingafearsome only latelyaswell. the book’s pigments,Mayablue, wasdiscovered depicted inthecodex.Thecompositionofone is thatscholarsonlyrecentlyofthedeities learned indeed thereal deal.Themostpersuasiveevidence the bookMayaArchaeologyin2016showsthatitis period-correct papertakenfrom ancientcaches. One offourMayacodicesinexistence,thework A newstudyoftheGrolier Codexpublishedin  NATHANIEL SCHARPING ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Dawning of the ■ ■ 65 ■ Planet of the Apes ■ ■ ■ RESEARCHERS HAVE UNEARTHED ■ the most primitive ■ primate yet discovered, a tree-dwelling creature that could ■ ■ nestle in the palm of your hand, according to an October ■ ■ paper in the Journal of Human Evolution. They found 25 ■ ■ bones from the creatures among 54.5 million-year-old ■ fossils discovered in Gujarat, India. ■ ■ Though the species ■ ■ resembled today’s gray ■ ■ mouse lemurs, its limbs ■ were unfit for acrobatic ■ ■ leaping between trees ■ ■ and branches or for slow ■ ■ climbing, says lead author ■ ■ Rachel Dunn of Des The gray mouse lemur (above) is the closest living ■ Moines University. approximation of the evolutionarily primitive primates ■ discovered in the Vastan Mine in India’s ■ Although other primate ■ These tiny fossilized bones, femurs state of Gujarat (below). ■ fossils are technically older, from ancient primates (shown CHINA ■ some by at least 500,000 with a U.S. quarter for scale), are ■ among the cache of primitive ■ years, the latest examples bones discovered in India. ■ INDIA ■ are the most primitive GUJARAT ■ ■ in terms of evolutionary development, and likely ■ ■

R; JOHNS HOPKINS MEDICINE; JAY SMITH; JAY JOHNS HOPKINS MEDICINE; R; approximate our oldest primate ancestors. The discovery ■ sheds light on the dawn of primates, which eventually led ■ ■ to monkeys, apes and humans. ■ Vastan Mine ■ “These fossils give us the best picture of what that very ■ ■  MARK BARNA first primate looked like,” Dunn says. ■ ■ ■ ■ ■ ■ ■ ■ ■ 66 ■ The Nose Knows Antibiotics ■ ■ ■ THINK TWICE BEFORE blowing Microbiologists at the University ■ ■ your nose — bacteria living there could of Tübingen in Germany swabbed ■ save your life someday. noses, looking for bacteria to test ■ ■ According to a July paper in Nature, against pathogens, and they scored ■ researchers found a new antibiotic with Staphylococcus lugdunensis. The ■ ■ produced by nose-dwelling bacteria bacterium produced an antibiotic, ■ ■ that kill drug-resistant superbugs, dubbed lugdunin, which killed a slew ■ including MRSA. of superbugs in cell cultures and mice ■ ■ As such bacteria evolve defenses with no signs yet of growing resistance. ■ against our current drugs, finding new Lugdunin also shows that the ■ ■ antibiotics is increasingly important. human microbiome — bacteria living ■ ■ “Far from being an apocalyptic on and within us — is an untapped ■ fantasy,” warned a 2014 World Health source for novel antibiotics. “It’s not ■ ■ Organization report, a world without just a new molecule,” says study author ■ Cultures of Staphylococcus lugdunensis, ■ antibiotics is “a very real possibility for native to the human nose, can produce Andreas Peschel, it’s “an action that ■  BRIDGET ALEX ■ OPPOSITE: ENRICO FERORELLI, DRAWINGS OF UNDERPAINTING BY STEPHEN HOUSTON (2). THIS PAGE FROM TOP: DAVID HARING/DUKE LEMUR CENTE DAVID TOP: FROM THIS PAGE (2). BY STEPHEN HOUSTON DRAWINGS OF UNDERPAINTING ENRICO FERORELLI, OPPOSITE: 2016 JULY AL./NATURE/10.1038/NATURE18634/28 ZIPPERER ET A. PUBLISHERS LTD: REPRINTED BY PERMISSION FROM MACMILLAN the 21st century.” lugdunin, a powerful antibiotic. gives hope.”

January/February 2017 DISCOVER 67 2016 68 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 67 would becompletely different. differently, ourbiology likely ourmoleculeswere flipped if looks theway itdoes, because to helpexplain why lifeon Earth molecules inspaceisafirststep handed forms. to possessbothleft-andright- in lifeonEarth,itisknown particular moleculeisnotfound ourgalaxy.center of While this Sagittarius B2,which isnearthe gasanddustcalled cloud of propylene oxide inavast theorganic compound traces of radio telescopespicked upfaint by Caltechresearchers inJune, could prove fatal. thesame molecule, andit of handed. Changetheorientation form, while sugarsare right- theleft-handed must allbeof chiral. Inparticular, aminoacids that make upourbodiesare right hand. left-handed glove over your but you couldnever slidea thesamematerial, are madeof Each glove hasfive fingersand gloves.as beinglike apairof eachother.mirror images of thesameatoms, butof are in two forms that are composed that exhibits chirality: Itcanexist a moleculeininterstellarspace researchers have discovered FOR THEFIRSTTIME,  NATHANIELSCHARPING Finding evidence of chiral Finding evidence of In thisdiscovery, reported The aminoacidsandsugars chiral molecules Think of Mirror-Image Molecule Far,Mirror-Image Far Away images ofeachother. chiral moleculesare mirror Like oppositehands, -rpln xd S-propylene oxide R-propylene oxide Sgr B2 Sgr A* traces ofpropylene oxide. center ofourgalaxy—contains near SagittariusA*atthe Sagittarius B2—whichsits The vastgasanddustcloud

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DISCOVERMAGAZINE.COM 68 WHEN RESEARCHERSLOOKED and published in Neanderthal DNA. What Gronau and colleagues discovered, — it’s why mostpresent-day humanshave about 2percent years ago, modernhumansinterbred withNeanderthals story that justhasn’t beentolduntilnow,” hesays. thought] maybe thisisreal andmaybe ittellsaninteresting initially thoughttheunexpected DNA was aglitch.“[ThenI data analysis onpreviouslymethods of studiedgenomes, and Interdisciplinary ateamapplying Center. new Hewas partof Ilan Gronau, acomputational biologist at Israel’s Herzliya Neanderthal from Siberia,they saw DNA that didnotbelong. thinking of yet.” thinking of history isriddled withcuriousthingsthat peopleare noteven complete demographic history. Says Gronau: “Evolutionary matingability andinfera todetectunknown episodesof Europe andnever reached Africa. appear tohave traveled; researchers believe theyevolved in Coincidentally, that’s thefarthestsouththat Neanderthals ambiguous fossils andartifacts, mostly from theMiddle East. a group previously hadonly beenhypothesized based on apparently leftAfricamore than100,000years ago. Such modernhumans,inherited from now agroup extinct, who of mated withourspeciessome50,000 years earlier. We already knew that, afterleaving Africaroughly 65,000 That storywas anundetectedaffair inhuman evolution. “No matter how we tried tofixit,itdidn’t go away,” says The genius of thesenew computational methodsistheir The geniusof They identifiedDNA intheSiberianNeanderthalthat was  ALEX BRIDGET Nature Out ofAfrica? Our FirstDate inFebruary, isthat Neanderthals also at the genome of a at thegenomeof years ago. than 100,000 hooking upmore sapiens left) and Neanderthals (far were Homo 69 how mitochondriawere completely lost. for evidence incloserelatives that shows says, adding that next upissearching mitochondria’s importance, Karnkowska in thejournal in Vancouver. Thework was published BritishColumbia at theUniversity of bacteria,” says AnnaKarnkowska, now stole orborrowed clusteringsystemsfrom functions were missing. genes associated withallmitochondrial analyzed the the iron-clustering duty. When theteam simpler mitochondriathat only perform chemicals. Afew related pathogens have and sulfurtohelpproteins make needed produce energy, andtheyglomontoiron perform many jobs. Mitochondria mitochondria. of nuclei —found withoutthemachinery and animals, whose cellscontain distinct first eukaryote —organisms, like plants isolated from achinchilla’s gut.Thisisthe Monocercomonoides identified thecellularequivalent in Republic and Canadian scientists Czech parts underthehood.Ateamof not only anengine, but withoutmost IMAGINE ACAR No Problem Machinery? No Mitochondria PAUL SMAGLIK  The protozoan mitochondrial functions. the genesthatare associatedwithall The rarity of thisexception confirms The rarity of So how doestheorganism survive? “It These cellularpowerhouses can Monocercomonoides Current Biology Monocercomonoides , aprotozoan they that runsminus inMay. genome, lacks

FROM TOP: PHOTO5963_SHUTTER/SHUTTERSTOCK; FRIEDRICH SAURER/SCIENCE SOURCE (2); BIOTECHNOLOGY AND BIOMEDICINE CENTER OF THE ACADEMY OF SCIENCES/CHARLES UNIVERSITY IN VESTEC ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 70 ■ Figuring Out FRBs ■ ■ ■ ■ THE ENIGMATIC SIGNALS known as fast radio bursts the course of two months all came from the same ■ ■ (FRBs) finally got a little less mysterious this year. direction of deep space — also home to an FRB ■ True, astronomers still don’t know the origins of observed last year — and each burst appears to have ■ ■ these extragalactic milliseconds-long radio pulses, traveled the same distance. They’re almost certainly ■ ■ and until this year fewer than 20 had ever been coming from the same space object. Mysteries remain, ■ ■ detected. But starting in December 2015, new FRB however: The bursts did not arrive at regular intervals, ■ ■ detections came in from observatories around the and they all have different signal strengths. ■ world, including the Green Bank Telescope in West “The discovery of a repeating FRB has not only ■ ■ Virginia and the Molonglo Observatory Synthesis narrowed down the possible astrophysical origins ■ ■ Telescope in Australia. of FRBs,” says lead author Laura Spitler of the ■ ■ The most important FRB announcement of 2016 Max Planck Institute for Radio Astronomy in ■ came from Puerto Rico’s Arecibo Observatory, which Bonn, Germany, “but we also have a better shot at ■ ■ reported in March the first repeating FRB. unraveling their nature by being able to observe more ■ ■ The 10 new bursts observed at Arecibo over bursts from this source.”  YVETTE CENDES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Puerto Rico’s Arecibo Observatory ■ ■ picked up 10 new fast radio bursts, ■ helping shed light on their origins. ■ ■ ■ ROBERT BARKER/CORNELL UNIVERSITY BARKER/CORNELL ROBERT

January/February 2017 DISCOVER 71 2016 72 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 71 RESEARCHERS IN a problem.” is faulty. . . basically onewrench has showed isnotthat thewhole toolbox the toolbox,” Nicholssays. “What we fMRIstudies.”of anumber questions “thevalidity of Updated language inthestudy now dialing backthe40,000figure: Thomas Nichols, issuedacorrection, years. the authors, Plus, one of software andanalysis methodsfor problems withfMRIstatistical other researchers have debated on thenews, neuroscientists and up to70percent. spitting outfalsepositives at arate of one particularanalysis variation was study. Theresearchers that realized as theywould inatraditional fMRI resting state, andanalyzed thedata scans from 499healthy peopleina simulated data. Sotheyused fMRI calibrated withreal data, just packages theyexamined weren’t and when. areas were significantly more active software pinpointswhich brain cranks outimages, statistical analysis for activity.) OncetheMRImachine fMRI reveals blood flow, aproxy MRI, which maps brain structure, brain activity over time. (Unlike neuroscience largely becauseitmaps common imaging techniquein thetime. more thanhalf brain activity where there wasn’t any, packages couldindicate significant popular statistical analysis software invalid. Theproblem? Themost imaging (fMRI)studiescouldbe 40,000 functionalma summer, seemingtoclaimnearly U.K. landedinthenews over the “We toolsin have acollectionof While mainstream mediajumped The teamclaimsthesoftware FMRI isbecomingamore LACY SCHLEY LACY When Brain ImagingGoesAwry Sweden andthe gnetic resonance which weren’t partofthatstudy, showthebraininaresting state. though somesoftware accuracywasrecently called intoquestion.Theimagesabove, Brain imagingwithfMRIreveals bloodflowinthebrain, servingasaproxy foractivity,

ANN CHOE ET AL./PLOS ONE/DOI:10.1371/JOURNAL.PONE.0140134/2015 ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ How Juno ■ ■ ■ 72 ■ Met Jupiter ■ ■ ■ NASA’S JUNO PROBE ■ entered Jupiter’s orbit in the ■ fading hours of July 4, giving American researchers ■ ■ one more reason to celebrate. The spacecraft, which ■ ■ will study the solar system’s biggest planet in closer ■ ■ detail than ever before, traveled for almost five ■ years across some 1.7 billion miles. Named after ■ ■ the mythological god Jupiter’s wife, who could see ■ ■ through her husband’s tricks, Juno will peer through ■ ■ the planet’s atmosphere, measure its composition ■ and map its powerful magnetosphere. Early findings ■ ■ revealed unique storm systems on the planet’s north ■ ■ pole and a surprising depth to its ribbon-like cloud ■ ■ patterns. After the 20-month mission, the probe will ■  BILL ANDREWS ■ plummet into Jupiter’s clouds. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ In late August, Juno’s stunning images of stormy Jupiter (above) ■ rewarded astronomers for their patience after more than a decade ■ without a dedicated spacecraft at the planet. NASA scientists now ■ plan to use Juno to skim closer than ever to Jupiter’s atmosphere, ■ ■ as shown in this artist illustration (left). ■ ■ ■ ■ ■ ■ ■ 73 ■ ■ This Metallic Glass Is Super-Tough ■ ■ ■ IN HER LAB at the University of the researchers had anticipated. As ■ ■ Southern California, Ph.D. student Gauri they described in Scientific Reports in ■ Khanolkar carefully placed a sample of March, despite its glass-like structure, ■ ■ a new material called SAM2X5-630 in this material, part of a class called bulk ■ ■ front of the barrel of a propellant gun. metallic glasses, is stronger than steel. ■ Created by her collaborators, the sample These strange glass-like metals are ■ ■ was shiny, about the diameter of a also bouncy, so combined with that ■ quarter and appeared to be metallic. But toughness, SAM2X5-630 could be ■ ■ inside, its atoms were disorganized, the especially useful in manufacturing. ■ ■ way they are in glass. Imagine a phone you could hurl against ■ Khanolkar left the room; even from the ground and have bounce back to you ■ ■ outside, she could still hear the “pop!” A transmission electron microscopy image intact, or a spacecraft with a strong but ■ of a bullet slamming into the sample. of the new material SAM2X5-630 shows springy surface that easily deflects debris. ■ the metallic compound’s disorganized inner ■ When she ran the numbers, she found For now, researchers will focus on ■ structure, usually a hallmark of glass. This ■ something strange: The sample had combination makes for an incredibly strong uncovering why SAM2X5-630 can take ■ ■ FROM TOP: NASA/JPL-CALTECH/SWRI/MSSS; NASA/JPL-CALTECH; UC SAN DIEGO NASA/JPL-CALTECH; NASA/JPL-CALTECH/SWRI/MSSS; TOP: FROM withstood a force nearly double what and flexible material. so much force.  SHANNON PALUS

January/February 2017 DISCOVER 73 2016 74 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 7 75 Great BarrierReef. Theanimals than ashoppingmallinAustralia’s only known habitat, anisland smaller ( hundred Bramble Cay melomys climate change. Inthe1970s, several by human-induced mammal killedoff made headlinesinJune asthefirst AN OBSCURERAT-SIZED RODENT plant (below)separatestheCO ground. AnIcelandicgeothermal steam and locks it below the surface. steam andlocksitbelowthesurface. CO An injectionsitecore (top) shows Melomys rubicola 2 -bearing rock captured under- 4 Poster Critter for Climate Change Climate for Critter Poster ) scurriedabout their 2

from the New Stone Age the New Age Stone Carbon Dioxide and increasing thetemperature andpressure before injectingitinto basaltrock. Laboratory, says theteam’s solutionbringsthegastoa“supercritical state,” any water. Todd Schaef, ageochemistat thePacific Northwest National 2016 that ithadfound away carbondioxide tomineralize —withoutadding dioxide from theatmosphere. But itssuccessisnoteworthy amidsomeproblematic efforts topullcarbon panacea becauseitusesmore water thansomeindustrialsitescanoffer. or groundwater. Theproject, calledCarbFix,won’t actasaglobalwarming sequestration projects, where carbondioxide canleakintotheatmosphere limestone. intocalciumcarbonate,mineralized themaincomponentof plantandinjectedit,alongwithwater,geothermal intobasaltrock. Thegas carbon dioxide intostone. Theteamcaptured carbondioxide emittedby a IN JUNE,RESEARCHERS Going onestepfurther, anotherteamwas expected toannounceinlate This transformation from gastosolidavoids other thepitfallsof rodents food andshelter. vegetation, which once provided the theisland’s97 percent herbaceous of decade, risingseashave destroyed Overdue toglobalwarming: thepast Researchers declared thespeciesextinct them. in 2014,found notrace of searches, including anextended survey were lastspottedin2009;subsequent working inIcelandannouncedtheyhadturned BRIDGET ALEX BRIDGET in byhuman-inducedclimatechange. Melomys rubicola the basalt,turningCO chemical reaction with allowing ittoundergo a bothgas andliquid, of dioxide hasproperties Once supercritical, carbon into stone. approach.” you’d want togowith our that wastewater, perhaps But where you don’t have will make perfectsense. “the CarbFixmethod wastewater,” says, Schaef that produces alotof “In anoperation , thefirstmammaldone  STEVE VOLK  STEVE 2

FROM TOP: CARBFIX/SANDRA SNAEBJORNSDOTTIR; AP PHOTO/BRENNAN LINSLEY; IAN BELL/QUEENSLAND DEPARTMENT OF ENVIRONMENT AND HERITAGE PROTECTION ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ A Happy Feat ■ ■ ■ 76 ■ Ross Ice for Antarctica ■ Shelf ■ ■ IN LATE OCTOBER, an international commission ■ announced an unprecedented agreement more than six ROSS SEA MARINE ■ PROTECTED AREA ■ ANTARCTICA ■ years in the making: the world’s largest marine protected ■ area, more than twice the size of Texas, in Antarctica’s ■ ■ Ross Sea. It’s also the first major reserve in non- ■ ■ territorial waters outside the jurisdiction of any nation. ■ ■ Although some restricted research fishing will be allowed ■ in about a quarter of the area, the agreement, beginning ■ ■ December 2017, prohibits the activity in more than ■ ■ 70 percent of the Ross Sea Marine Protected Area. ■ ■ In addition to being home to penguins, seals and other ■ iconic Antarctic wildlife, the Ross Sea is part of the ■ The new Ross Sea ■ greater Southern Ocean, which contains powerful currents Marine Protected ■ Area (above), at ■ that direct nutrient-rich water toward Earth’s other ■ over twice the size ■ oceans. Mike Walker, director of the advocacy group of Texas, will be ■ Antarctic Ocean Alliance and an observer at the meeting the world’s largest ■ marine reserve. ■ where the agreement was announced, said the Ross Sea It will protect a ■ ■ preserve is a win for the planet. “If arboreal forests are the pristine ecosystem ■ teeming with life, ■ lungs of the planet,” says Walker, “the Southern Ocean is from sea stars ■  GEMMA TARLACH (right) to emperor ■ its heart.” ■ penguins (below). ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ FROM TOP: PEW CHARITABLE TRUSTS; HENRY KAISER/NATIONAL SCIENCE FOUNDATION; PAUL NICKLEN/NATIONAL GEOGRAPHIC/GETTY IMAGES NICKLEN/NATIONAL PAUL SCIENCE FOUNDATION; KAISER/NATIONAL HENRY TRUSTS; PEW CHARITABLE TOP: FROM

January/February 2017 DISCOVER 75 2016 76 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 77 likely looked a lot like the modern capuchinmonkey,likely lookedalotlikethemodern seenabove. South Americabefore theIsthmusofPanamaformed. Panamacebus transitus New research reveals apreviously unknownmonkeyspecies, AMERICA NORTH , whicharrivedinNorthAmericafrom PANAMA Panama Canal Evolutionary Timeline Ancient Monkey Teeth Change of Panamawasfullyformed. a peninsulabefore theIsthmus water from SouthAmericato P. transitus traversedopen AMERICA SOUTH P. transitus

tooth structure. N. fieldsi early Mioceneera(roughly 20millionyearsago),with teethfrom A digitalcomparisonofteethfrom SEVEN FOSSILIZEDMONKEYTEETH the pioneerpopulation diedout. any monkeys currently living intheregion, indicating were probably short-lived: Theyappear unrelated to migration by more than12millionyears. mammals known tohave madethisintercontinental and NorthAmerica,perhaps onaraft —theearliest traveled then-openwater between South milesof population of the time. Theysuggesta that was apeninsulaat theisthmus on partof old teethwere found in April. the findonlinein the teamthat published years, according to of land bridgeby millions predate thePanamanian Panamacebus transitus monkey species the newly described teeth, which belongto 3.5 millionyears ago. was fully formed, about Panama Isthmus of north only afterthe there. Theyheaded debris from AfricatoSouthAmerica—andstayedof years ago, monkeys migrated by landbridgeoraraft 18 millionyears. theanimalsby nearlyNorth Americanarrival date of the recent Panama Canalexpansion pushedbackthe Sadly, thecontinent-hoppingexploits of The 21million-year- But thefossilized Researchers have longthoughtthat some30million aaaeu rniu Neosaimirifieldsi Panamacebus transitus , whichemergedafter P. transitus Nature ,

P. transitus expansion, inawaxjaw. the PanamaCanal’s recent the newspecies,foundduring displays thefossilteethof Researcher JonathanBloch P. transitus  GEMMA TARLACH butstillhadsimilar , whichlivedinthe discovered in P. transitus

CLOCKWISE FROM TOP LEFT: FLORIDA MUSEUM OF NATURAL HISTORY/KRISTEN GRACE (3); REPRINTED BY PERMISSION FROM MACMILLAN PUBLISHERS LTD: JONATHAN BLOCH ET AL./NATURE 533/12 MAY 2016/DOI:10.1038/NATURE17415; ALISON MACKEY/DISCOVER

2016 78 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM really get?” this question,” says van Dokkum.“How dark cangalaxies current galaxyformation theoriescan’t explain. “Itopensup Dragonfly 44’s mass must bedark matter —aproportion making itsoheavy? toourMilkysize Way —but farfewer stars. What’s andasimilar Dragonfly 44has roughly themassof in its massandothercharacteristics. Theiranalysis, published thesegalaxies, namedDragonfly 44,tolearn brightest of doesn’t interact withlight. mysterious substancethat holdsgalaxiestogether and dark matter,to bemadealmostentirely of thefamously faint, spread-out galaxies. Thesehard-to-find objectsseem new Dragonfly telescope, theyuncovered 47 extremely galaxiesclosetohome. Itpaidoff: Usingtheir light of to scourthesky inanew way —by lookingfor thehazy Toronto’sthe University of Roberto Abraham wanted universe. ButYale University’s Pietervan Dokkumand 78 ASTRONOMERS OFTENHUNT The astronomers calculated that 99.99percent of In early 2016, the pair tracked stars within one of the In early 2016,thepairtracked starswithinoneof The Astrophysical Journal Letters  KRUESILIZ of thegalaxy. dark matter, whichmakesupashocking99.99percent core. Dragonfly44isdimbecausemostofitsmass including thesphericalclustersofstars around its in (right)showsmore detailoftheelongatedgalaxy, barely visibleinthewide-angleshot(left).Zooming and massoftheMilkyWay, butit’s muchfainter, The galaxyDragonfly44isroughly thesamesize Milky Way A Dark faint objectsacross the thissummer, shows 79 Chemicals Chemicals EPA Toxic Ban New Law Lets CONGRESSIONAL LEADERS bipartisanship. throwback a bitof overhaul in2016 1976, gotan Act of last law, theToxic SubstancesControl everyday householdproducts.of That species andkeep toxic substancesout air andwater, protect endangered to passsweeping laws toensure clean the politically turbulent 1970smanaged stifling patchwork of regulations.stifling patchwork of state governments passed abusiness- court overturned therule. Inresponse, the agency bannedbefore afederal known carcinogens like asbestos, which alike. TheEPA was unable tocontrol eventually irked scientistsandindustry chemicals were never studied.Thelaw grandfathered in,andeven many new chemicals were some 55,000 ingredients. But to bandangerous (EPA) theauthority Protection Agency Environmental law gave the warranted, regulate. by December2016toevaluate and,if tasked with picking10initialchemicals an EPA priority. Theagency was but alsomakes regulating carcinogens of chemicalsitactson.” of asbestos inthisinitiallist all forms of agency inAugust. “EPA must consider who supportedthebill,wrote tothe years,” California Sen.Barbara Boxer, EPA’s agenda for the next several The original The 2016law reduces states’ power, “The chemicalsselectedwilldrive  ERIC BETZ  ERIC backin

FROM LEFT: PIETER VAN DOKKUM, ROBERTO ABRAHAM, GEMINI, SLOAN DIGITAL SKY SURVEY; TUNART/GETTY IMAGES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Scientists deciphered the ages ■ ■ of Greenland sharks using ■ radiocarbon dating of eye ■ proteins and nuclear fallout. ■ ■ ■ ■ ■ ■ ■ ■ ■ Greenland Sharks ■ ■ ■ ■ ■ Can Live 500 Years ■ ■ ■ ■ ■ 80 ■ and Counting ■ ■ ■ ■ LIVE SLOW, DIE OLD. That’s the sexual maturity around 150. This centuries, but the researchers could ■ ■ way of Greenland sharks. ranks them among the oldest improve the estimates because ■ ■ These behemoths putter through invertebrates, surpassed only by the smallest sharks measured ■ Arctic waters at roughly 1 mile per sedentary invertebrates like clams. showed the “bomb pulse” — a huge ■ ■ hour, growing less than a pinky’s A team led by University of increase in global radiocarbon ■ ■ width per year. Yet adults reach Copenhagen biologist Julius released from the hundreds of ■ ■ lengths of 16 feet, suggesting the Nielsen radiocarbon-dated eye nuclear weapons tested in the 1950s ■ sharks have long lives. proteins formed at birth from the and ’60s. Knowing these sharks ■ ■ The first study to measure corpses of 28 sharks accidentally were born in the Atomic Age, and ■ ■ their ages, published in August in killed by fishing vessels and during assuming the animals grew at ■ ■ Science, revealed extraordinary scientific surveys. a predictable rate, the scientists ■ ■ longevity. Greenland sharks can Normally, radiocarbon dates calculated ages for the remaining ■  BRIDGET ALEX ■ DOUG PERRINE/NATURE PICTURE LIBRARY DOUG PERRINE/NATURE live upward of 500 years, reaching have error ranges of several sharks based on size.

January/February 2017 DISCOVER 79 2016 80 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 82 81 JAPAN’S RESEARCHERS FROM highlighted ingreen, hasnot lab-grown skin,thenew version, recipients. Unlike earlier one day may help skingraft stem cellsinaprocess that have grown skinfrom mouse announced inApril that they very close to true spiders. But the back half isstillrathervery closetotruespiders. primitive.” Butthebackhalf which thingsevolved inspiders,” says evolved Garwood. first;thelimbsandmouthpartsare “Thefront half that published thefindingsinMarch, todigitally reconstruct the fossil infinedetail.“Ittellsusthe order in siderite, amineral. That Manchesterpaleontologist Russell allowed theteam University of Garwood, partof first truespiders ever found. The roughly 305million-year-old fossil was preserved in3-Dinsidealump of THIS ITSY-BITSY FOSSIL, RIKEN institute A Leg UponArachnid Evolution A Hairy Situation Offers Hope for Skin Grafts Skin Hopefor Offers Situation A Hairy Idmonarachne brasieri soon tookroot. them tonaked mice, where hair maturity before transplanting to helpthestemcellsgrow to Researchers usedfurrymice and oil-producing glands. skin, completewithhairfollicles just onebut allthree layers of  NATHANIELSCHARPING — less than half aninchlong—istheclosestrelative tothe —lessthanhalf GEMMA TARLACH GEMMA

TOP: RUSSELL GARWOOD ET AL./PROCEEDINGS OF THE ROYAL SOCIETY B/ VOLUME 283 ISSUE 1827/2016. BOTTOM: TAKASHI TSUJI/RIKEN CENTER ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Bypassing ■ ■ ■ Paralysis ■ ■ 84 ■ ■ Altogether ■ ■ ■ IAN BURKHART WAS 19 WHEN HE BROKE HIS NECK, ■ leaving ■ him a quadriplegic, paralyzed and unable to move his upper ■ ■ body from the elbows down. Now, six years later, he can control ■ ■ This cell’s gene-editing system targets his fingers enough to play the video gameGuitar Hero. And it’s ■ RNA, revealing the molecule’s distribution all thanks to a so-called neural bypass. ■ in the cytoplasm. ■ Burkhart is the first person to undergo this procedure, ■ ■ reported by Battelle Memorial Institute and Ohio State ■ ■ University researchers in May in Nature. Ninety-six electrodes ■ were implanted in his brain, and his arm was wrapped in ■ 83 ■ an electrode-studded cuff. Following hours of practice, ■ ■ a computer ■ ■ CRISPR Edits learned to identify ■ ■ brain signals ■ associated with ■ Cells’ RNA ■ different wrist and ■ DESPITE THE PROMISE ■ of gene finger movements. ■ editing for treating disease, altering genes ■ And unlike in ■ can be risky and pose ethical challenges. other techniques, ■ So researchers from the University of ■ which send these ■ California, San Diego and UC Berkeley ■ signals to a ■ instead focused on using the editing ■ technique called CRISPR-Cas9 to prosthetic limb, ■ ■ manipulate the product of those genes. the computer ■ routed the ■ Back to freshman biology: As you may ■ remember, double-stranded DNA makes signals directly ■ ■ single-stranded RNA, which makes to Burkhart’s ■ proteins. Edit DNA and the proteins are ■ actual muscles, ■ altered forever. But edit the RNA and electrically ■ the genetic machinery stays the same Ian Burkhart, whose upper body was paralyzed from the ■ stimulating them ■ while the proteins can be manipulated, elbow down, uses a neural bypass to grasp a coffee cup. ■ via the cuff. The device restores movement directly to his arm. ■ so the levels of gene expression are dialed The equipment ■ up or down. Theoretically, RNA editing ■ is restricted to use inside the lab. But future versions might be ■ is reversible, and since it doesn’t change ■ portable, according to lead researcher Chad Bouton, now with ■ the genome, it won’t be passed down ■ to descendants. the Feinstein Institute for Medical Research. They may also ■ ■ Gene Yeo, a professor of cellular be less invasive, he says, eliminating the risks of brain surgery. ■ and molecular medicine at UCSD, led ■ One promising approach would be using a so-called stentrode. ■ the research and showed he could target A new invention developed by an international team ■ ■ RNA in living cells, a first step toward under University of Melbourne neurologist Thomas Oxley, ■ treating diseases like muscular dystrophy ■ the stentrode is implanted using a microcatheter and intended ■ and neurodegeneration. (Later in the to last for life. It detects brain signals from inside a blood vessel ■ year, a Boston-based team targeted RNA ■ near the motor cortex and relays those signals to a computer. ■ in bacteria using a different Cas protein.) ■ So far, Oxley’s group, which published its findings inNature ■ “We had to show that [RNA targeting] ■ was feasible in living cells,” Yeo says in February, has successfully read sheep brain signals. In 2017, ■ ■ about his March paper in Cell. “Now, they’ll try the device on human participants — paralyzed ■ ■ we are trying many different ways patients who will use stentrodes to control mechanical ■  KAREN WEINTRAUB  JONATHON KEATS ■ ABOVE: UC SAN DIEGO HEALTH. RIGHT: THE OHIO STATE UNIVERSITY WEXNER MEDICAL CENTER/BATTELLE UNIVERSITY THE OHIO STATE RIGHT: UC SAN DIEGO HEALTH. ABOVE: of improving it.” exoskeletons.

January/February 2017 DISCOVER 81 2016 82 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 85 finally figured out how. the richsoilswe seeonourplanettoday. Andnow, experts have forms. Onetiny fungushelpedtransform that aridground into rocks,landscape sandanddust,inhospitable of tomostlife- Journal of theLinneanSociety Journal of more complex organisms,of from plantstoworms. fed, itcreated nourishingsoil,settingthestage for theevolution They thendecomposedandscattered thenutrients. Asthefungus absorbed lichen,bacteriaandalgaeblowing about inthesand. ahumanhair,to develop them.Shorterthanthewidthof theroots threadlike roots, but revealing itsspecialskill. Durham University was able toreconstruct how thisfungusgrew, examining England’s new samples, paleontologist MartinSmithof from fossils collectedover thepastthree decades. Butafter eventually tobloom, andhumanstoevolve. CONSIDER LIFEONEARTH early days. soil inEarth’s sand into that turned a fungus Tortotubus Filaments of Scientists hadknown about thefungus Smith believes thisprocess, describedinMarch inthe It’s allabout themycelial networks. Allmodernfungihave these , Tortotubus to Soil From Sand 440 millionyears ago: agrayish , iswhat allowed theworld appears tohave beenthefirst Tortotubus protuberans

 KATHERINEELLISON Botanical

86 the Dino Call of than 100timesthesize. thumping comingfrom a noise.” Now considerthat ominous Every malealligator was makingthat THUMP THUMP. “the room exploded indeepthumps. facility slammedshut,says Clarke, and Bronx ZooinNew York. Adoorinthe Chinese alligator breeding project at the experience years ago when shevisiteda at Austin, who recalled aheart-pounding Texaspaleontologist at theUniversity of it from study co-authorJulia Clarke, a crocodilians today. mostly closed-mouthvocalizations, like Verdict: Dinosaursprobably made extinctliving dinosaurs. relatives of birds andcrocodilians,of thenearest at theanatomy andsoundrepertoire weren’t mute, either. these beloved anatomy justwasn’t built for it.But Dinosaurs didnotroar. Their LET’S GETTHISSTRAIGHT: Think that’s notasimpressive? Take A June study in

( beasts of theMesozoic beasts of Evolution  GEMMA TARLACH GEMMA T. rex T. looked , more

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DISCOVERMAGAZINE.COM 87 88 EVEN SEASONED FOR THEFIRSTTIME, Garnavich. rect,” explains teamleaderPeter core collapse supernovae iscor- that thefundamentalideaof milestone; italso“demonstrates event isn’tbrief just atechnical oursun. of size away androughly 500timesthe KSN2011d, 1.2billionlight-years breakout occurred within thestar Kepler spacecraft. Theshock stars captured by the planet-hunting studying lightfrom some50trillion the discovery inMarch after breakout, that lasts20minutes. light,called ashock a burst of reaches thestar’s surface, itreleases brightness. When thecollapsing core process cantake weeks toreach peak known asasupernova. Theentire and triggersaviolentexplosion itslife, itcollapses fuel at theendof supernova. triggers onetypeof window into whatan extremely brief exploding star’s “shockbreakout” — have captured invisible lightan fingerprint was different from any years ago. ButÖst65’s chemical at thesametime, roughly 470million typical meteorites, suggestingithitEarth found in thesamelimestoneasmore 065 (Öst65)afterthequarrysite — was mysterious object—calledÖsterplana Swedish quarry for spacerocks. The had spenttwo decadesinspectinga the 3-inch“mysterious object” in2011. Birger Schmitzgotexcited when hesaw The observation of such a sucha The observation of An international teamannounced When amassive starrunsoutof Schmitz, aLundUniversity geologist,  YVETTE CENDES  YVETTE Shocker! Supernova A Fossil From Heavens the meteorite hunter astronomers like allthoseyears ago. a glimpseintowhat thesolarsystemwas real,” Schmitzsays. Findingonegives us hold itinyour handcanyou say it’s for extinct meteorites, but “notuntilyou can obliterated by collisions. float inspace, having beentotally meaning otherslike itnolonger the firstknown “extinct” meteorite, announce inJune that Öst65may be meteorite found onEarth. Scientists have speculated about This ledSchmitzandcolleagues to illustration. light, asinthis burst ofvisible includes ashort which supernova, explodes asa star dies,it When amassive  BRIDGET ALEX  BRIDGET Shock breakout sizable samplesexist. in Sweden,isextinct,meaningnoother Meteorite Öst65,foundinlimestone Meteorite

TOP: NASA AMES, STSCI/G. BACON. BOTTOM: BIRGER SCHMITZ/MARIO TASSINARI ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 89 ■ Digging Deep for ■ ■ 90 ■ Science Explains New Bacteria ■ ■ ■ Why Ankle-Biters MICROBIOLOGISTS OFTEN SEEK LIFE ■ in the planet’s extremes ■ ■ — from below ice sheets to within geysers. But Appalachian Basin ■ Bite Ankles scientists found hydraulic fracturing, or fracking, also provides its ■ ■ own inhabited extremes in their backyard. ■ ■ The process mixes water with sand and chemicals, then uses the ■ ■ pressurized concoction to rip open rocks underground and liberate ■ natural gas. And that’s where the never-before-seen bacterium ■ ■ Candidatus Frackibacter thrives — 1.5 miles deep in the salty ■ ■ leftovers. ■ ■ For nearly a year, ■ researchers sampled ■ ■ and grew bacteria ■ ■ AN UNPRECEDENTED SEARCH for from the wastewater ■ ■ the roots of canine aggression and fear has of two wells hundreds ■ identified genetic variants that predispose of miles apart ■ ■ a dog toward such behaviors. And the in different rock ■ ■ researchers hope that knowledge could formations, according ■ eventually help treat humans with anxiety. ■ to their September ■ The research, published in August Nature Microbiology ■ in BMC Genomics, compared owner ■ paper. Surprisingly, ■ reports of a pet’s behavior and genetic ■ the wells had nearly ■ data from 30 purebred lines to discover ■ the 16 genome regions. The team also found identical ecosystems, ■ ■ that two clusters of these genes control and C. Frackibacter ■ lived in both. ■ different kinds of aggression: one directed ■ at strangers and strange dogs, and the other The team also ■ ■ directed at the owner and other dogs in found 30 already ■ the household. ■ known organisms, ■ Dachshunds are particularly prone to a which likely were ■ genetic variant that study co-author Carlos ■ injected into the ■ Alvarez of Nationwide Children’s Hospital ■ fracking wells from ■ calls “freak biology.” That low-riding surface ponds. But ■ wiener dog body comes with an increased ■ Frackibacter lived ■ likelihood of snarls and snapping. ■ Annually, dogs bite more than 4.5 million only in wastewater, ■ Fracking sites (top) shoot pressurized water ■ Americans; understanding the roots of and researchers underground to access natural gas. Scientists found ■ ■ canine aggression is a public health priority. suspect it was key a whole ecosystem in the leftovers (above). ■ Alvarez cautions, however, that it’s unfair ■ to creating the wells’ ■ to label dogs with the genetic variants as self-sustaining ecosystems. ■ ■ aggressive. Instead, he hopes testing leads The scientists are now sampling other wells, but they’re also ■ to better diagnosis and treatment of dogs ■ hunting Frackibacter in rock cores from pristine, unfracked sites. ■ — and, ultimately, their best friends. “That would be the real clincher, that Frackibacter is indigenous ■ By knowing which genetic variants pose ■ to the system,” says Ohio State University microbiologist and ■ an increased risk, Alvarez thinks he can ■ study co-author Kelly Wrighton. ■ determine which exact cells are responsible ■ — the signaling mechanism — and target How did it get there in the first place? Frackibacter could’ve ■ ■ them. “Once we prove it works in dogs, been entombed in rock eons ago and sat dormant until the ■ ■ it should also work in humans,” he says. wastewater arrived, Wrighton says. “I’m hopeful we’ll see other ■  GEMMA TARLACH  ERIC BETZ ■ CLOCKWISE FROM TOP: VLAKYR/ISTOCK; ROY MORSCH/GETTY IMAGES; REBECCA DALY/THE OHIO STATE UNIVERSITY OHIO STATE REBECCA DALY/THE MORSCH/GETTY IMAGES; ROY VLAKYR/ISTOCK; TOP: CLOCKWISE FROM things like it now that we know to look.”

January/February 2017 DISCOVER 85 2016 86 YEAR IN SCIENCESCIENCE

DISCOVERMAGAZINE.COM 91 fueled new speculation. Just don’t ask believe themythic rulerlived, which has sixth century—when Arthurenthusiasts a royal palaceprobably from thefifth or Instead, researchers found what may be No fabled round table here, though. legendaryKingArthur’s conception. of castle, haslongbeenclaimedasthe spot coast. Thesite, dominated by amedieval at Tintagel CastleonEngland’s southwest afive-yearin July excavation at thestartof ARCHAEOLOGISTS STRUCKPAY DIRT King Arthur's Roots Arthur's King In Search of would bedodgyarchaeology,” Scuttsays. not tryingtoassociate itwithArthur. That got tohangitonArthur, OK,but we’re which mediahave they’ve embraced. “If Tintagel project, Win Scutt,about thelink, the properties curator responsible for the to Arthuriantimes. (right) helpedresearchers datethestructure a royal palace.RelicslikePhoenicianpottery in Englandfoundremains ofwhatcouldbe Excavators attheTintagelCastlesite (above)  GEMMA TARLACH GEMMA

EMILY WHITFIELD-WICKS/ENGLISH HERITAGE (2) ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 93 ■ ■ ■ ■ ■ ■ ■ Helium Fields Forever? ■ ■ ■ WHEN PROSPECTORS DISCOVERED ■ the first underground ■ ■ helium reserve in 1903, they deemed the gas useless because ■ it wasn’t flammable and couldn’t be sold as fuel. Over a century ■ ■ later, liquid helium is an invaluable coolant for MRI scanners, and ■ ■ the gas also has applications in nuclear power, deep-sea diving ■ ■ and (of course) party balloons. Yet supplies on Earth are finite ■ and unreliable because reserves have only been found accidentally ■ ■ during petroleum exploration. ■ ■ Now, experts have discovered one of the world’s largest helium ■ ■ fields in the Tanzanian Rift Valley — this time, on purpose. A team ■ led by Durham University geologist and former oil prospector ■ 92 ■ Jon Gluyas, together with Oxford University geochemist Chris ■ ■ Ballentine, adapted oil prospecting methods to ■ ■ Eye Spy a suss out ways Earth might concentrate helium gas ■ ■ generated naturally ■ Single Photon by underground ■ ■ radioactivity. KENYA ■ AS YOU’RE READING THIS, ■ The Tanzanian ■ millions of photons — particles ■ reserve will likely ■ of light — are flooding your eye. provide enough helium ■ TANZANIA ■ In the 1940s, experiments showed for over 100,000 ■ that humans who have adjusted ■ MRI machines, and ■ to the dark could detect as few ■ the team’s methods Dar es Salaam ■ as a half dozen or so photons. can easily be applied ■ ■ Was there a limit to how low we elsewhere on the planet. ■ could go? In July, after decades ■ Pump up the party Rift Valley ■ of attempts, researchers showed in ZAMBIA ■ balloons and celebrate. ■ a paper in Nature Communications  JONATHON KEATS ■ ■ that we’re capable of detecting ■ ■ a single photon — proving our ■ eyes can see the absolute minimum ■ ■ amount of light possible. ■ ■ Researchers in Vienna built ■ ■ a laser setup that spits out one ■ photon at a time, itself a technical ■ ■ challenge. They put it in a ■ ■ lightproof room and had three ■ ■ subjects test their night-vision ■ ■ mettle. It was no easy task: Over ■ thousands of trials, the testers ■ ■ were able to correctly identify ■ ■ whether or not a photon had been ■ ■ deployed just slightly over half the Experts developed a technique to locate Earth’s helium reserves, uncovering one ■ ■ FROM TOP: JENNIFER HULS/123RF.COM; JAY SMITH; CARSTEN PETER/NATIONAL GEOGRAPHIC CREATIVE CARSTEN PETER/NATIONAL SMITH; JAY JENNIFER HULS/123RF.COM; TOP: FROM time.  SHANNON PALUS in Tanzania’s Rift Valley (above). Previously, reserves were found only by chance.

January/February 2017 DISCOVER 87 2016 88 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 95 equate to a lack of effectiveness.”equate toalackof strong evidence doesn’tadmonition that “alackof to which thedentalassociation added itsown that “flossing isanimportantoral hygiene practice,” and HumanServicestoconcedeinapublic statement Health Dental Association gottheDepartmentof dropping theflossing recommendation. The guidelinescommitteeresponded insteadby government flossing’s for evidence of effectiveness. scientific support for theguidelines. TheAPasked the for Americans included inthegovernment’s The Associated Press investigated why flossing is flossing. supposed benefitsof by news that noscientific evidence supportsthe dentists say. ButinAugust, that advice was upended GOOD ORALHYGIENE 94 specific moleculeintheskinthat sumac: Scientistshave identifiedthe to rashes from poisonivy, oak and GOOD NEWS But thecontroversy didn’t endthere. TheAmerican Following atipfrom adisgruntledorthodontist, , learningthat federal law requires for peoplesusceptible Researchers Finally ID Poison Ivy Suspect PoisonIvy ID Finally Researchers To Flossor Notto Floss depends ondaily flossing, Dietary Guidelines at Harvard MedicalSchoolwho Florian Winau, animmunologist to carryCD1a,according to through testsonmiceengineered the connectionthisfall confirmed inflammation. Researchers resin, calledurushiol,ittriggers in contactwiththeplants’ oily system moleculeCD1acomes suspected that when the immune eventually resolves theitch. which couldbethescratch that plays arole intheinflammation, For decades, researchers have of dental sciencedependsonit. of and toothdecay. contending that gumdisease flossing lowers theriskof casualstudies anecdotal evidence andasmattering of Now what’s needed isrigorous research. Thehealth Meanwhile, somedentistshave brought forth August in thestudy published in was partof antibody. company todevelop ananti-CD1a working withapharmaceutical identified, Winau says hislab is the skin. fattyCD1a andnormal acidsin triggered by interaction between one day treat psoriasis, which is says, theantibody mightalso spurred by plantcontact,Winau Now that themoleculehasbeen Besides treating inflammation  MARK BARNA  MARK Nature Immunology  JONATHONKEATS in pink). (shown molecule by aCD1a is entrapped in poisonivy, ingredient the active (in green), Urushiol .

CLOCKWISE FROM TOP: KHOMULO ANNA/SHUTTERSTOCK; IMAGING COE; JESSICA KIM ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ WELCOME TO THE ■ ■ ■ ■ ANTHROPOCENE ■ ■ ■ ■ HUMANITY HAS ETCHED its existence into the rock ■ ■ layers beneath our feet. And now, scientists look to Earth’s ■ bedrock and see enough evidence to officially usher ■ ■ us into the Anthropocene — a time period sometimes ■ ■ defined as the “human epoch.” ■ ■ The term Anthropocene first gained popularity in 2000, ■ but it wasn’t formally recognized as a part of the geologic ■ ■ timescale. This year, members of the Anthropocene ■ ■ Working Group, a subset of the International Union of ■ ■ Geological Sciences (the body that oversees the geologic ■ timescale), sought to change that. They recommended ■ ■ that we officially mark the end of the Holocene, the ■ ■ current epoch, and enter the Anthropocene. ■ ■ If the larger body ratifies their proposal, we will be ■ ■ living in the age of humans. Next, the researchers need ■ to find a “golden spike,” a unique boundary point in the ■ ■ rock strata that signifies the epoch’s beginning. ■ ■ That golden spike will likely come from radioactive ■ ■ particles spread around the globe by atmospheric nuclear ■ tests in the 1950s, starting off our geologic reign with ■ ■  NATHANIEL SCHARPING ■ ANTON BALAZH/SHUTTERSTOCK ANTON a bang.

January/February 2017 DISCOVER 89 2016 90 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 97 New Tree ofLife Bacteria BeefUp A SHALLOWAQUIFER Desert —Banfieldcreated anew Life. Tree of from Yellowstone hotspringstoChile’s Atacama uncovered there —andat otherinhospitable sites, the unexpected biodiversity sheandhercolleagues to samplethewater for geneticmaterial. Given geomicrobiologist JillianBanfieldvisitedthesite California, Berkeley,until University of Rifle, Colorado,of isprime real estate for bacteria. life. Butitturnsoutthatforms thearea, of nearthetown floodplain doesn’t springtomindasahotspot for new Mapping thegeneticrelationship between species, the Nobody expected toseesuchalively community

beneath theColorado River Bacteria Archaea Wirthbacteria Dojkabacteria WS6 Dojkabacteria published in April in each other,” this Banfieldsays,version, andthegoal of and thenpuzzlingtogether individual genomes. metagenomically: sequencing eachcommunity’s DNA overcame theproblem by analyzing environments be cultivated inalab. Banfieldandhercolleagues because approximately theworld’s half bacteriacannot life—mostly bacterial—onEarth.That’sa third of tree shows that scientistshave been oblivious tonearly grow inapetri dish. that accountsfor diverse possibilitiesbeyond what can provide abalancedsampling.” It’s life anew view of A Tree Lifeshows “how organisms are of related to WWE3 Katanobacteria CPR1 CPR3 Nomurabacteria Curtissbacteria Azambacteria Daviesbacteria Levybacteria Giovannonibacteria SM2F11 Yanofskybacteria Radiation, detailed above. Radiation, detailedabove. branch, CandidatePhyla features anewbacterial bacterial branches.Italso species throughout the previously unknown This newtree includes Gottesmanbacteria JONATHON KEATSJONATHON Berkelbacteria Falkowbacteria Moranbacteria Nature Microbiology Uhrbacteria Roizmanbacteria Magasanikbacteria Campbellbacteria Kaiserbacteria Adlerbacteria Beckwithbacteria Saccharibacteria Peregrinibacteria Wolfebacteria Eukaryotes Jorgensenbacteria Pacebacteria Gracilibacteria BD1-5,GN02 Gracilibacteria Absconditabacteria SR1 Absconditabacteria Collierbacteria Amesbacteria Shapirobacteria Parcubacteria Microgenomates Woesebacteria Phyla Radiation Candidate , was “to

REPRINTED BY PERMISSION FROM MACMILLAN PUBLISHERS LTD: HUG ET AL. NATURE MICROBIOLOGY/10.1038/NMICROBIOL.2016.48/11 APRIL 2016 ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ 98 Above the Fray ■ ■ ■ IT’S A TYPICAL ■ urban planning them 6.5 feet above two lanes of ■ dilemma: Subways are costly rush-hour gridlock at a steady ■ ■ to build, but buses get stuck in 37 mph. But critics worry about ■ ■ traffic. In the Chinese port city safety, such as minimal headroom ■ ■ of Qinhuangdao, a new form of for road traffic, and infrastructure ■ transit is being tested. Combining demands. If tests are successful, ■ ■ the mobility of subways with the the elevated bus might one day ■ ■ cost effectiveness of buses, this help congested Chinese cities ■ ■ elevated vehicle straddles the become navigable again. ■ road so that car traffic can travel  JONATHON KEATS ■ ■ unimpeded underneath. Supported ■ ■ by roadside rails, the electric- A city in China is testing the Transit Elevated ■ Bus, which straddles the road so that traffic ■ powered Transit Elevated Bus can can proceed underneath unimpeded. The bus ■ hold 300 passengers, transporting can transport up to 300 passengers at a time. ■ ■ ■ ■ ■ ■ ■ ■ 99 ■ ■ Degas’ Other Woman ■ ■ ■ USING A PARTICLE ACCELERATOR, researchers in Australia uncov- ■ ■ ered a second woman’s face hiding beneath the 19th-century painting ■ Degas’ hidden ■ “Portrait of a Woman,” by French impressionist Edgar Degas. portrait of a younger ■ woman appeared ■ The researchers bombarded the painting with high-energy X-rays, ■ after researchers ■ causing the elements that make up the hidden pigments to fluoresce, or used X-rays to scan ■ the canvas. ■ light up. Matching the wavelengths to pigments from the period revealed ■ a mystery woman, believed to be Emma Dobigny, a model popular with ■ ■ painters of the time.  NATHANIEL SCHARPING ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Beneath Edgar Degas’ “Portrait of a Woman,” ■ completed sometime between 1876 and 1880 ■ ■ TOP: LUO XIAOGUANG/XINHUA VIA AP (2). BOTTOM: NATIONAL GALLERY OF VICTORIA/AUSTRALIAN SYNCHROTRON (3) SYNCHROTRON VICTORIA/AUSTRALIAN OF GALLERY NATIONAL BOTTOM: AP (2). VIA LUO XIAOGUANG/XINHUA TOP: (above), is an earlier portrait (right).

January/February 2017 DISCOVER 91 2016 92 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM 100 2016 MAY BEREMEMBERED the Stars to Breakthrough future spaceexploration.” technologies that willbeusefulin at a minimum, helpusdevelop stars,” hesays, “but itshould, “Starshot may notgetustothe Astrophysics ismore cautious. Harvard-Smithsonian Centerfor Jonathan the McDowell of Space buffs are thrilled,though necessary research anddevelopment. $100 milliontosupportthe have, Milnerispersonally donating light. thespeed of to 20percent of imparting enoughforce toaccelerate eachprobe lasers would thenfocus itsbeamsonindividual sails, ground-basedorbit, andasynchronized array of rockets would carrytheminiature probes intoEarth comparableultrathin mass. sailsof Conventional weighing justagram; they’d beaffixed tosturdy, wafer-thin devices loadedwithmicroelectronics and within ourreach.” Ames Research Center. “Thestarsare finally Pete Worden, theNASA theformer headof dreamed about,” saidStarshotExecutive Director purpose.stars hasgiven themissionanextra senseof Centauri’sroughly planetorbitingoneof Earth-sized a their destination. Thesubsequentdiscovery of within 20years andtake another20years toreach 25 trillionmilesaway. Theprobes would launch nearest starsystem,AlphaCentauri, more than robotic spaceprobesto sendasquadron tothe of bold program, Breakthrough Starshot.Itsmission: Russian-born entrepreneur Yuri Milnerunveiled a stars suddenly gotawhole lotcloser. OnApril 12, While theplanrequires technology we stilldon’t The spacecraft for thisventure would betiny, “Today istheday that spaceexplorers have  STEVE NADIS  STEVE as theyear when the ■ ■ ■ ■ ■ ■ ■ ■ STATEMENT OF OWNERSHIP, MANAGEMENT, AND CIRCULATION (ALL PERIODICALS PUBLICATIONS EXCEPT REQUESTER PUBLICATIONS) ■ ■ 1. Publication Title: DISCOVER ■ 2. Publication Number: 555-190 ■ 3. Filing Date: Oct. 1, 2016 ■ 4. Issue Frequency: 10 x per year ■ 5. Number of Issues Published Annually: 10 ■ 6. Annual Subscription Price: $29.95 ■ 7. Complete Mailing Address of Known Office of Publication: ■ 21027 Crossroads Circle, Waukesha, WI 53186 ■ Contact Person: Katie Sattler, 262-798-6626 ■ 8. Complete Mailing Address of Headquarters or General Business Office of Publisher: ■ 21027 Crossroads Circle, Waukesha, WI 53186 ■ 9. Full Names and Complete Mailing Addresses of Publisher, Editor, and Managing Editor ■ Publisher: Dan Lance, 21027 Crossroads Circle, Waukesha, WI 53186 Editor: Becky Lang, 21027 Crossroads Circle, Waukesha, WI 53186 ■ 10. Stockholders owning or holding one percent (1%) or more of total amount of stock are: Deborah ■ H.D. Bercot, 22012 Indian Springs Trail, Amberson, PA 17210; Gerald and Patricia Boettcher ■ Trust, 8041 Warren Ave., Wauwatosa, WI 53213; Alexander & Sally Darragh, 145 Prospect Ave., ■ Waterloo, IA 50703; Melanie J. Duval, 9705 Royston Ct., Granite Bay, CA 95746; Harold Edmonson, ■ 6021 N. Marmora Ave., Chicago, IL 60646-3903; Laura & Gregory Felzer, 3328 S. Honey Creek Dr., Milwaukee, WI 53219; Susan E. Fisher Trust, 3430 E. Sunrise Dr., Ste. 200, Tucson, AZ 85718; Bruce H. ■ Grunden, 255 Vista Del Lago Dr., Huffman, TX 77336-4683; Linda H. Hanson Trust, 363G Bateman ■ Circle S., Barrington Hills, IL 60010; Mary Kay Herrmann, 1530 Tallgrass Circle, Waukesha, WI 53188; ■ George F. Hirschmann Trusts, 363G Bateman Circle S., Barrington Hills, IL 60010; James & Carol ■ Ingles, 1907 Sunnyside Dr., Waukesha, WI 53186; Charles & Lois Kalmbach, 7435 N. Braeburn Ln., Glendale, WI 53209; Kalmbach Profit Sharing/401K Savings Plan & Trust, P.O. Box 1612, Waukesha, ■ WI 53187-1612; James & Elizabeth King, 2505 E. Bradford Ave. #1305, Milwaukee, WI 53211-4263; ■ Mahnke Family Trust, 4756 Marlborough Way, Carmichael, CA 95608; Jennifer McGraw, 630 Quail ■ Run, Colgate, WI 53017; Milwaukee Art Museum, Inc., 700 N. Art Museum Dr., Milwaukee, WI 53202; James W. Mundschau, N24 W30420 Crystal Springs Dr., Pewaukee, WI 53072; Daniel & Mary ■ Murphy, 4722 Lincrest Dr., Brookfield, WI 53045; Lois E. Stuart Trust, 1320 Pantops Cottage Ct. #1, ■ Charlottesville, VA 22911-4663; David M. Thornburgh Trust, 8855 Collins Ave., Apt. 3A, Surfside, FL ■ 33154-0436 ■ 11. Known Bondholders, Mortgagees, and Other Security Holders Owning or Holding ■ 1 Percent or More of Total Amount of Bonds, Mortgages, or Other Securities: N/A ■ 12. Tax Status: Has not changed during preceding 12 months ■ 13. Publication Title: DISCOVER ■ 14. Issue Date for Circulation Data: SEP-16 ■ 15. Extent and nature of circulation ■ ■ Average No. No. Copies of Copies Each Single Issue ■ Issue During Published ■ Preceding Nearest to ■ 12 Months Filing Date ■ a. Total Number of Copies 520,201 482,300 ■ b. Paid Circulation (By Mail and Outside ■ the Mail) ■ (1) Mailed Outside-County Paid ■ Subscriptions Stated on PS Form 3541 322,320 292,900 ■ (2) Mailed In-County Paid ■ Subscriptions Stated on PS ■ Form 3541 0 0 ■ (3) Paid Distribution Outside the Mails ■ Including Sales Through ■ Dealers and Carriers, Street Vendors, Counter Sales, and Other ■ Paid Distribution Outside the USPS® 41,402 30,400 ■ (4) Paid Distribution by Other Classes ■ of Mail Through the USPS ® ■ (e.g., First-Class Mail )00 ■ c. Total Paid Distribution (Sum of 15b (1), (2), (3), and (4)) 363,722 323,300 ■ d. Free or Nominal Rate Distribution (By ■ Mail and Outside the Mail) ■ (1) Free or Nominal Rate Outside- ■ County Copies Included on ■ PS Form 3541 0 0 ■ (2) Free or Nominal Rate In-County Copies Included on PS Form 3541 0 0 ■ (3) Free or Nominal Rate Copies ■ Mailed at Other Classes Through ■ the USPS (e.g., First-Class Mail) 250 250 ■ (4) Free or Nominal Rate Distribution ■ Outside the Mail ■ (Carriers or other means) 0 0 ■ e. Total Free or Nominal Rate Distribution (Sum of 15d (1), (2), ■ (3), and (4)) 250 250 ■ f. Total Distribution (Sum of 15c ■ and 15e) 363,972 323,550 Breakthrough ■ g. Copies Not Distributed 156,229 157,750 ■ Starshot aims to h. Total (Sum of 15f and g) 520,201 482,300 ■ send tiny space i. Percent Paid (15c divided by 15f ■ times 100) 99.93% 99.92% probes (left) to ■ Alpha Centauri 16. Electronic Copy Circulation ■ ■ (above). The project, Average No. No. Copies of Copies Each Single Issue ■ funded by Russian Issue During Published ■ entrepreneur Yuri Preceding Nearest to ■ 12 Months Filing Date Milner (center), was ■ announced with a. Paid Electronic Copies 24,484 19,049 ■ b. Total Paid Print Copies (Line 15c) + ■ great fanfare at a Paid Electronic Copies (Line 16a) 388,206 342,349 ■ gathering in New c. Total Print Distribution (Line 15f) + ■ Paid Electronic Copies (Line 16a) 388,456 342,599 ■ York that included d. Percent Paid (Both Print & Electronic Stephen Hawking Copies) (16b divided by 16c x 100) 99.93% 99.93% ■ ■ and other big 17. Publication of Statement of Ownership: If the publication is a general publication, publication of this statement is required. Will be printed in the JAN/FEB-17 issue of this publication. ■ names (right). ■ ILLUSTRATION: ESO/L. CALÇADA/NICK RISINGER (SKYSURVEY.ORG). INSETS: BREAKTHROUGH INITIATIVES INSETS: RISINGER (SKYSURVEY.ORG). CALÇADA/NICK ESO/L. ILLUSTRATION: 18. Signature and Title of Editor, Publisher, Business Manager, or Owner: Nicole McGuire, Date: 9/27/16

January/February 2017 DISCOVER 93 DiscoverSCIENCE FOR THE CURIOUS MAGAZINE®

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DISCOVERMAGAZINE.COM IMAGE OF THE YEAR OFTHE IMAGE Shadow Play ENGULFED IN A coronal halo and topped by a ruby- colored solar flare, the moon’s face is evident during last March’s solar eclipse, seen from Tidore Island in Indonesia. Romanian photographer Catalin Beldea took 12 rapid- fire pictures at varying shutter speeds to capture the brilliant corona and the much dimmer moon, lit only by earthshine. Alson Wong, a California physician and amateur stargazer, digitally combined the frames into one spectacular photograph, revealing what the naked eye cannot see because of the corona’s glare. In 2017, the solar eclipse spectacle will land in the United States for the first time in 38 years. Millions are expected to gaze up Aug. 21 as the moon’s shadow races along a path from Oregon to South Carolina.  ERNIE MASTROIANNI

January/February 2017 DISCOVER 97 2016 98 YEAR IN SCIENCE

DISCOVERMAGAZINE.COM p. 27 p. 89 p. 23 p. 36 p. 80 p. 57 Index Archaeology/Paleontology/Anthropology permission ofKalmbachPublishingCo., 21027CrossroadsCircle, P.O. Box 1612, Waukesha, WI 53187-1612. PrintedintheU.S.A. Agreement #40010760, returnallundeliverable CanadianaddressestoP.O. Box 875, STN A Windsor, ON, N9A6P2. Backissuesavai Box 1612, Waukesha, WI 53187-1612. Periodical postagepaidat Waukesha, WI, andatadditionalmailingoffices. POSTMASTER: Send DISCOVER (ISSN0274-7529, USPS#555-190)ispublishedmonthly, exceptforcombinedissuesinJanuary/February andJuly/August. Medicine/Genetics Earth/Environment/Energy #43 Living World #14 #13 #11 #6 #9 Sciences Math/Physical #25 #23 #18 #97 #90 #80 #69 #62 #59 #54 #44 #93 #76 #75 #74 #41 #66 #47 #37 #34 #31 #30 #73 #45 #35 #10 #56 #91 #86 #85 #81 #77 #68 #65 #64 #51 #38 #36 #28 #24 #16 #15 #5 #3 #4 Confirmed:Birdssleepwhileflying Ozoneholeisfinallyhealing Coralreefssuffer devastatingbleaching DiscoveryofdeadlythreatunderBangladesh 2016’s climatechangeroundup DidfamoushomininLucyfalltoherdeath? Labdivideshumaneggcells Firstartificial speciescreated Effects ofZika’s spread Fail:LHC’s huntfornewparticle AlegendaryArthurianpalacefound? Whatdinosaurssoundedlike Fungusturnedsandintosoil Fossilshowshowspidersevolved Monkeys’firstmigrationtoNorthAmerica Thegreatarchaichumanhook-up Mostprimitiveprimatediscovered OldestbookinAmericasauthenticated Tully monstermysterysolved Amateurarchaeologistsfindstill-sharpsword Newlinkin ExpertsfindPhilistinecemetery EvidenceforChina’s greatflood New“Hobbit”fossilsfillevolutionarygaps OldestDNArevisesevolutiontimeline Antibioticsinbooger-dwelling bacteria ZincsparksIDhealthyhumaneggs Theranosbloodtestsabust Antibiotic-resistant superbughitsU.S. Ethicsof embryoslivinglongerinlabs Depression’s geneticroots Metallic glassstrongerthansteel Neutron-only atom Shortcutforellipticcurves’manysolutions Pushingthelimitsofperiodictable Primenumbers revealoddbehavior Electronsshatterintonewformofmatter Tree oflifegrowsnewbranches Newbacteriathriveinfrackingwastewater Giantsharkslivelongtime Cellssansmitochondria Pepperedmoth’s colormutationfound Virushacksbacterialimmunity withCRISPR Linkbetweenscales,feathersandhair 2016’s newspeciesmakeashow ofit Majorheliumreservediscovered Antarctica’s RossSeagetsprotection Mammalextinctviahuman-causedclimatechange Turning carbondioxideintostone Ourmoon’s roleinearthquakes Homo sapiens T. rex migrationtimelinerevealed evolution ......

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