PAGE THE QUEST TO EXPLAIN THE GALAXY’S STRANGEST STAR 36 DAWN OF TECHNOLOGY The discovery of 3.3-million-year-old stone tools overturns long-standing views on human evolution PLUS HOW TO TURN A FOX INTO A DOG A bold experiment tests ideas about domestication PAGE 68 A WILD CARD IN CLIMATE CHANGE India’s choices could have a profound impact PAGE 48 WORLD’S FASTEST CAMERA MAY 2017 Chemical reactions caught on film PAGE 62 ScientificAmerican.com © 2017 Scientific American MAY 2017 VOLUME 316, NUMBER 5 68 ARCHAEOLOGY NEUROSCIENCE 28 The New Origins 54 Schizophrenia’s of Technology Unyielding Mysteries Ancient stone tools from Kenya Major gene studies have shatter the classic story of when failed to identify the disorder’s and how humans became innova­ causes, so scientists are tors. By Kate Wong broadening the search. ASTROPHYSICS By Michael Balter 36 Strange News CHEMISTRY from Another Star 62 Split-Second Is alien technology making Boy a­ Reactions jian’s star flicker? It’s surprisingly Never before seen images of hard to rule out. By Kimberly drug proteins or photosynthesis Cartier and Jason T. Wright in action show how the molecules EVOLUTION work—or fail. 42 Missing Links By Petra Fromme Defining human traits may have and John C. H. Spence emerged when we shed key pieces GENETICS of DNA. By Philip L. Reno ON THE COVER 68 How to Early human ancestor knaps stone tools, using CLIMATE Build a Dog an anvil and hammerstone to remove sharp 48 The Global Warming To test ideas of animal domestica­ flakes from a core. Archaeologists working in Wild Card tion, a bold experiment in Siberia Kenya have uncovered stone tools dating to India’s energy decisions could put evolution on a fast track. 3.3 million years ago—the oldest artifacts in the world. The discovery has upended conventional determine the fate of the planet. By Lyudmila Trut and wisdom about the origins of our genus, Homo. COURTESY OF LYUDMILA TRUT AND INSTITUTE OF CYTOLOGY AND GENETICS By Varun Sivaram Lee Alan Dugatkin Image by Jon Foster. May 2017, ScientificAmerican.com 1 © 2017 Scientific American 4 From the Editor 6 Letters 9 Science Agenda Marching for science is good. Voting is much better. By the Editors 10 Forum A healthy democracy depends on the free and open pursuit of knowledge. By Jonathan Foley 12 Advances Reconciling faith and evolution education. Brains remember languages lost in childhood. An agile robot 10 to leap walls. Greener road to a hydrogen economy. 24 The Science of Health Aspirin might reduce cancer’s ability to spread. By Viviane Callier 26 TechnoFiles How to build a better battery. By David Pogue 74 Recommended Apollo 8’ s historic orbit of the moon. How the natural world helps humans innovate. Intuition can blind us to science. By Andrea Gawrylewski 77 Skeptic Torture still doesn’t work. By Michael Shermer 16 78 Anti Gravity The greatest taboos in American science are ... medical marijuana and gun violence? By Steve Mirsky 79 50, 100 & 150 Years Ago 80 Graphic Science Why the Northwest Passage is so elusive. By Katie Peek ON THE WEB The Eyes Never Lie Richard Schwartz of the Graduate Center, City University of New York, uses eye­tracking technology to better under­ stand children with specific language impairment (SLI). Go to www.ScientificAmerican.com/may2017/sli 79 Scientific American (ISSN 0036-8733), Volume 316, Number 5, May 2017, published monthly by Scientific American, a division of Nature America, Inc., 1 New York Plaza, Suite 4500, New York, N.Y. 10004-1562. Periodicals postage paid at New York, N.Y., and at additional mailing offices. Canada Post International Publications Mail (Canadian Distribution) Sales Agreement No. 40012504. Canadian BN No. 127387652RT; TVQ1218059275 TQ0001. Publication Mail Agreement #40012504. 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Scientific American is part of Springer Nature, which owns or has commercial relations with thousands of scientific publications (many of them can be found at www.springernature.com/us). Scientific American maintains a strict policy of editorial independence in reporting developments in science to our readers. Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations. 2 Scientific American, May 2017 © 2017 Scientific American FROM THE EDITOR Mariette DiChristina is editor in chief of Scientific American. Follow her on Twitter @mdichristina light­years away from Earth? Probably not, write Kimberly Car­ Dawn of tier and Jason T. Wright in their feature, “Strange News from Another Star.” Still, the two astronomers are among those who find it difficult to account for the dramatic and sporadic dim­ Innovation ming with natural phenomena. Theorists posit ex­­otic possible explanations, among A number of animals employ existing ob jects them­­­ comet swarms or black holes. Beyond to carry out certain tasks. Seagulls drop mol­ those is the intriguing possibility of an lusks onto rocks to crack open a snack, for ex ­ ad­­vanced cosmic civilization. Sound far­ ample. Corvids wield twigs to create in­­sect­ fetched? Turn to page 36 to learn more. gathering hooks. Apes probe termite mounds Technology has its downsides, of course. with sticks. But humans have taken tool use to a Thousands of studies demonstrate that hu ­ level no other creature has ever matched. Tech­ man activity, including the burning of fossil nology innovation is so extensive that Michael fuels, has led to global climate change. But Haslam of the University of Oxford has said, how bad will it be? That’s a question that will “It’s like an addition to our bodies.” depend at least in part on the actions of a In this issue’s cover story, “The New Origins of number of major emitters. Technology,” starting on page 28, senior features In “The Global Warming Wild Card,” start­ editor Kate Wong investigates its surprisingly ing on page 48, Varun Sivaram, a fellow at the ancient beginnings. Recently Sonia Harmand Council on Foreign Relations and acting direc­ and her husband, Jason Lewis, both at Stony tor of its program on Energy Security and Climate Change, ex ­ Brook University, discovered 3.3­million­year­old tools at a site amines one wild­card country in our climate future: India. With in Kenya called Lomekwi 3. The great age of the implements— its population and living standards rising quickly, India could far too early to be made by our own species, Homo —is forcing prevent the world from limiting global warming to sought­for researchers to rethink what they believed they knew about the levels—or it could help make the difference in a better future. It origins of technology and how incorporating tools into our exis­ is already the third­largest emitter after China and the U.S. but tence has, in turn, shaped the human family tree. could become the largest by midcentury if it does not take Could alien technology be causing the mysterious dimming strong measures. Can India make a low­carbon transition? Tech­ of Boyajian’s star, also known as KIC 8462852, more than 1,000 nical and financial support from other nations will be crucial. BOARD OF ADVISERS Leslie C. Aiello Kaigham J. Gabriel Christof Koch Martin A. Nowak Terry Sejnowski President, Wenner-Gren Foundation President and Chief Executive Officer, President and CSO, Director, Program for Evolutionary Professor and Laboratory Head for Anthropological Research Charles Stark Draper Laboratory Allen Institute for Brain Science Dynamics, and Professor of Biology and of Computational Neurobiology Roger Bingham Harold “Skip” Garner Lawrence M. Krauss of Mathematics, Harvard University Laboratory, Salk Institute for Co-Founder and Director, Director, Origins Initiative, Biological Studies The Science Network Executive Director and Professor, Robert E. Palazzo Arizona State University Michael Shermer Arthur Caplan Primary Care Research Network Dean, University of Alabama at Publisher, Skeptic magazine Director, Division of Medical Ethics, and Center for Bioinformatics and Morten L. Kringelbach Birmingham College of Arts and Sciences Associate Professor and Senior Michael Snyder Department of Population Health, Genetics, Edward Via College Carolyn Porco NYU Langone Medical Center of Osteopathic Medicine Research Fellow, The Queen’s College, Professor of Genetics, Stanford Leader, Cassini Imaging Science Vinton Cerf University of Oxford University School of Medicine Michael S. Gazzaniga Team, and Director, CICLOPS, Chief Internet Evangelist, Google Steven Kyle Michael E. Webber Director, Sage Center for the Study Space Science Institute George M. Church of Mind, University of California, Professor of Applied Economics and Co-director, Clean Energy Incubator, Director, Center for Computational Management, Cornell University Vilayanur S. Ramachandran Santa Barbara and Associate Professor, Genetics, Harvard Medical School Robert S. Langer Director, Center for Brain and Cognition, Department of Mechanical Engineering, David J. Gross Rita Colwell David H. Koch Institute Professor, University of California, San Diego University of Texas at Austin Distinguished University Professor, Professor of Physics and Permanent Department of Chemical Lisa Randall Steven Weinberg University of Maryland College Park Member, Kavli Institute for Theoretical Engineering, M.I.T.