The Search for Extreme Life

BIOCHEMIST_BARUCH S. BLUMBERG The Search for Extreme Life

ofile If microorganisms exist on other worlds, the head of NASA’s fledgling Astrobiology Institute plans to find them

he relentless heat cooks the the space agency aims to someday find “Technology is available to decipher Pr Badwater region of California’s on other worlds. the intricacies of this cause-and-effect Death Valley so thoroughly that “I always liked the idea of doing field- chain” that wasn’t available even five some expanses are textured like work, exploring, going out and finding years ago, Blumberg notes, citing in par- Tdry serpent skin. At some 284 feet below new things,” Blumberg says back at NAI ticular advances achieved through the sea level—North America’s lowest point— headquarters, which is nestled near Sili- Human Genome Project. The 1996 an- it is perhaps the hottest place on the sur- con Valley at the NASA Ames Research nouncement of potential fossilized life in face of the earth: the temperature once Center at Moffett Field. Out of his desert a Martian meteorite known as ALH84001 peaked at a record 53.01 degrees Celsius garb, the outdoors-loving Blumberg looks boosted enthusiasm worldwide. Even (127.4 degrees Fahrenheit). Out here, a good decade younger than his 75 years. Congress, which had quashed NASA’s blood-pumping mammals are scarce. It At the job only since last September, Blum- search for extraterrestrial intelligence may seem unfitting to find a Nobel Prize berg is trying to marshal gaggles of as- (SETI) program in 1993, became recep- winner, renowned for hepatitis B work, tronomers, chemists, ecologists, geologists, tive. On sabbatical at Stanford University in this scorching pit. But Baruch S. Blum- biologists, physicists and even zoologists. in 1998, Blumberg, along with scores of berg’s latest challenge takes him beyond He is convinced that advances in molecu- others, helped to craft NASA’s Astrobiolo- human subjects. As the first director of the lar biology, space exploration and other gy Roadmap during a series of workshops. National Aeronautics and Space Adminis- endeavors make timely the reexamination It defined the role for the new institute. tration’s Astrobiology Institute (NAI), he is of such age-old issues as the origins of life “With NASA’s Astrobiology Institute searching for extreme life-forms, the kind and its possible existence elsewhere. we are witnessing not just a shift in scientific paradigm but, more important, a shift in cultural acceptability among sci- entists,” says extrasolar planet hunter Geoffrey W. Marcy of San Francisco State University. Already Blumberg’s institute is becoming “the intellectual basis for a broad range of NASA missions,” says NASA administrator Daniel S. Goldin. Goldin hopes to raise the NAI’s budget from about $15 million to $100 million within five years. The NAI now comprises some 430 astrobiologists at 11 universi- ties and research institutions. Although the institute is lending new credibility to the search for extraterrestrial life, X-Files fans needn’t hold their breath. Unlike the now privately funded SETI program, which focuses on radio transmissions and other hallmarks of presumably sentient beings [see “Where Are They?” by Ian Crawford, on page 38], the NAI is targeting microorganisms and other, even more primitive evidence of lifelike matter. Specifically, the NAI is looking for life in hostile environments— in deserts, volcanoes and ice caps; down BARUCH S. BLUMBERG: NONEXTREMOPHILE thousands of meters below Earth’s surface • Born July 28, 1925: “A very optimistic time” or into the ocean; and on Mars, Jupiter’s • Wife, Jean, a painter; daughters, Anne and Jane; sons, George and Noah moon Europa, Saturn’s satellite Titan, even • Most Important Field Trip: The Philippines in 1967 to test hepatitis virus theory planets beyond the solar system. • Best-Known Fact: Won 1976 Nobel Prize for Physiology or Medicine For now at least, extremophiles on Earth

• Least-Known Fact: His rustic western Maryland farm lacks indoor plumbing offer the most probable model for testing Liaison Agency • On Extraterrestrials in Our Solar System: “Highly evolved life is very unlikely, the hypothesis that life exists elsewhere. but we have to continue our search” NAI researchers hope to use genomic TIN KLIMEK AR M

30 Scientific American July 2000 Profile Copyright 2000 Scientific American, Inc. databases of key microorganisms to link pursue his own longing to be a scientist was the Rosetta stone for unraveling the evolutionary sequences with geochemi- and went in 1955 to the University of Ox- nature of the hepatitis viruses,” com- cal and paleontological events. Another ford, where he began his doctorate in bio- ments Robert H. Purcell, head of the NIH’s desire is to launch DNA microprobes on chemistry under Alexander G. Ogston. At hepatitis lab. board miniature spacecraft to search for the time, Oxbridge was buzzing with ex- This key finding enabled researchers to signs of life. Answers, if they ever come, citement over Watson and Crick’s discov- develop the first blood test to screen for

ofile may take many decades. ery of the DNA double helix. Blumberg the virus, thus protecting blood supplies. Blumberg believes his past biochemical himself had become intrigued with inher- In 1969 Blumberg and microbiologist Irv- work gives him intimate insights into life- ited genetic variations a few years earlier. ing Millman patented a strategy to devel- forms, whether of this world or not. “One In 1950 he had gone to a desolate min- op a hepatitis B vaccine. Their novel ap- Pr of the things about doing medicine and ing-town hospital in Suriname in South proach relied on purifying from the virus medical research is that you really get a America, where, besides witnessing the those very same surface antigen particles— kind of feeling for the organism that you devastation caused by infectious diseases, which by good fortune proved not only work with,” he observes. Hence, pro- he observed large differences in suscepti- to produce protective antibodies but to found questions of life “are coming di- bility to the elephantiasis parasite among be noninfectious. For advancing under- rectly and indirectly into your thinking.” diverse immigrant workers. A 1957 field standing of the mechanisms of infectious As a child in a tight-knit immigrant trip to West Africa formally launched his diseases, Blumberg shared the 1976 No- community in Brooklyn, N.Y., Blumberg study of such genetic variations, called bel Prize for Physiology or Medicine. checked out book after library book on polymorphisms, which he would contin- A commercial vaccine based on Blum- the reigning explorers. “Amundsen, Peary, ue at the National Institutes of Health. berg’s method, now made using recombi- Scott, Shackleton, Rae, Nansen nant DNA techniques, has saved tens of were common names in my millions of lives, according to World circle of friends,” he recalls. “I Health Organization estimates. Blumberg believe this had an effect on remains optimistic that hepatitis B can my seeing science as discovery. someday be eradicated, but today the My interest in fieldwork also fed virus continues to kill more than a million into this.” To this day he col- people a year, including 5,000 in the U.S. lects books on early travel and When not working, the Nobelist pre- Arctic expeditions. fers to birdwatch or kayak or even shovel After graduating from Far manure on a cattle farm he owns with Rockaway High School in friends in western Maryland. “That kind 1943, he enlisted in the Naval of manual labor is an antidote to too Reserves and secured a physics much thinking,” he says. degree at Union College in CRYPTOENDOLITHS—microcolonies of fungi, al- In Death Valley, Blumberg and other re- Schenectady, N.Y. At age 21 he gae and cyanobacteria (colored layers)—thrive inside searchers, led by Christopher McKay of made captain of a small U.S. this sandstone rock from cold and dry Antarctica, NASA Ames, used syringes to extract heat- Navy ship. “It is a great sensa- showing that life can exist in hostile conditions. loving microbes for DNA analysis back at tion to plot a course, take a few the lab. Blumberg plans to accompany re- sights, do some dead reckoning, and end Blumberg collected data on the distri- searchers on other field trips to collect up more or less where you had predicted. bution of polymorphisms. Initially, he extremophiles, perhaps in Mongolia’s It gives one confidence in the power of ap- culled blood for clues to disease resist- Gobi Desert or in Antarctica. Tests of new plied mathematics and the effectiveness of ance. To find possible variants, he and his robots for planetary exploration might rational solutions.” Captaining that crew colleagues relied on the natural immune even send him to the Canadian Arctic. 24 hours a day instilled an unshakable response to compare blood proteins from Besides guiding and inspiring his re- confidence in him. “I assumed that I frequently transfused patients, mainly he- searchers, Blumberg wants to take advan- would have leadership roles in whatever I mophiliacs. From antibodies in the pa- tage of powerful computers to model how did,” he says. tients’ bloodstream, they could derive for- life might evolve elsewhere. “Astrobiolo- In 1946, thanks to the G.I. Bill, Blum- eign antigens. In 1963 Blumberg’s team gy lends itself to iterated induction- berg started graduate school in mathemat- isolated a peculiar variant and dubbed it deduction exercises, as well as theory and ics at Columbia University, only to trans- “Australian antigen.” Common among model construction,” Blumberg explains. fer a year later to the medical school at the Australian Aborigines, Micronesians, Viet- He notes wryly that in this field “there’s a behest of his attorney father. For his med- namese and Taiwanese, the blood protein high probability you will reject the mod- ical internship and residency, Blumberg was rare among Westerners. The team, el.” Just the same, he and his followers picked the crowded, understaffed wards of however, observed it in leukemia patients hope the conditions that allow life to New York City’s Bellevue Hospital, where in the U.S., who also were receiving trans- flourish on Earth exist elsewhere in the the poor and chronically ill were typically fusions. The researchers set off exploring Milky Way and beyond. “It could hap- sent. “And this was before health insur- whether the unusual antigen played a pen,” Blumberg says. “In any case, you ance,” he emphasizes. Bellevue taught role in susceptibility to leukemia. have to go and look.” —Julie Wakefield TITUTE S

Blumberg a new deﬁnition of responsibili- Instead of an inherited immune factor, IN Y

ty: “The fact that you’ve got to do it—if the curious surface antigen proved to be JULIE WAKEFIELD writes frequently on OG you don’t do it, nobody else will.” part of the then mysterious hepatitis B science and technology. She is based in TROBIOL Equipped with an M.D., he decided to virus. “His discovery of Australian antigen Washington, D.C. S A S NA