In 1970, the biologist Lynn Margulis applied for a grant from the National Science Foundation. Three years prior, a small scientific journal had published Margulis’s paper in which she outlined a provocative theory about the evolution of life. She had hoped to continue that work with funding from one of the major federal agencies to support science and engineering research.
In a 1998 interview, she recalled what an NSF grant officer had told her: “There are some very important molecular biologists who think your work is shit.” According to Margulis, the officer also said her work appealed to “small minds” in biology. His message was clear: Your application is rejected, and don’t bother applying again.
At first, Margulis didn’t know where else to turn. But one major new scientific organization offered promise: The National Aeronautics and Space Administration had been founded just 12 years earlier, not long after the Soviet Union had launched Sputnik, the world’s first artificial satellite. Eager for the young agency to do work on the origin of life, a NASA scientist approached Margulis in 1971 and agreed to provide seed funding for her research.
“This was a key moment in modern biology,” said Robert Hazen of the Carnegie Institution for Science in an interview this year.
Up until then, many scientists embraced neo-Darwinism, a view of evolution in which change happens slowly and is driven by small, random genetic mutations that benefit an individual organism—be it a finch, a giant tortoise, an orchid, or a barnacle. Over time, these changes may lead to new forms of life. It’s a process that can be viewed in the fossil record. For example, two years after Charles Darwin published his classic text On the Origin of Species, a now-famous fossil was discovered of a creature with teeth, a long bony tail, and wings. Known as an Archaeopteryx, it is believed to represent a transitional form between dinosaur and bird.
But with NASA’s support—according to James Strick, co-author of The Living Universe, and others—Margulis and other scientists began to study life from a completely different perspective. Rather than only using fossils hidden in rock layers to study evolution, some researchers turned to the wide variety of living bacteria. What they produced in the ensuing decades was a new, microbial view of the evolution of life—one that today, according to Jan Sapp, a professor of biology and history at York University in Toronto, forms the foundation for evolutionary biology as it’s routinely taught in classrooms across the world. This line of inquiry has been buoyed by the emergence of advanced genetic sequencing tools that let biologists reconstruct, in increasingly exquisite detail, the steps taken over millennia of evolutionary change.
And all of that leaves NASA—an agency associated largely with feats of technology and engineering, devoted to interstellar exploration, and born of a bitter, militaristic, geopolitical space race—as the unlikely catalyst for a revolution in, of all things, biology.
On a Friday afternoon, October 4, 1957, a satellite went up—and by evening, the news had traveled around the world. “The success of Sputnik seemed to herald a kind of technological Pearl Harbor,” wrote Pulitzer Prize–winning journalist David Halberstam in his 1993 book The Fifties, echoing an observation from physicist Edward Teller. “Suddenly, it seemed as if America were undergoing a national crisis of confidence.” It was the Cold War, with Russia and the U.S. competing to lead the world into the future. Sputnik declared at a stroke that the Russians were winning the race. A book called Why Johnny Can’t Read—And What You Can Do About It became a smash bestseller. Life magazine printed an article called “Arguing the Case for Being Panicky.” And in government, the White House and Congress shifted gears. Science was suddenly front and center.
Within 11 months of Sputnik’s launch, President Dwight D. Eisenhower had created the job of presidential science adviser, Congress had increased federal education funds by more than a billion dollars, and NASA was founded with a $100 million annual budget.
NASA was founded to put American astronauts into space. But some scientists, led by Nobel Prize winner Joshua Lederberg, saw additional opportunities. In the weeks after Sputnik’s launch, Lederberg wrote memos to senior scientists around the country. A few months later he formalized those memos into an article for Science magazine.
Lederberg had seen Sputnik in the sky while on an academic trip in Australia. He was both exhilarated and frightened by what it portended for biology. Space had been breached. Much more would follow. Knowing a bit of history, he realized that humans had thoughtlessly contaminated every place they had visited on Earth. Now humans would soon be traveling to moons and planets.
“Since the sending of rockets to crash on the moon’s surface is within the grasp of present technique, while the retrieval of samples is not,” he wrote in Science, “we are in the awkward situation of being able to spoil certain possibilities for scientific investigation for a considerable interval before we can constructively realize them.”
As Lederberg and other scientists saw it, this was humanity’s first chance to look for life, or even for pre-life chemistry, beyond Earth. That meant, first, that spacecraft had to be sterilized in order to not contaminate samples with their own waste. Second, it meant figuring out what to look for. Water, carbon, other basic chemicals? What would life look like if it were just getting started? What would it look like where there were few resources?
NASA had been created with distinctly political and military ambitions. But scientists like Lederberg worked hard to insert science—in particular, origin-of-life research—into the agency’s mission and make it a civilian program. Ultimately, NASA appointed a 40-year-old biologist, Richard S. Young, to lead a program devoted to exobiology: a term coined by Lederberg to refer to scientific work on extraterrestrial life.
It was clear to Young that exobiology didn’t fit comfortably within the traditional biology of institutions such as the National Science Foundation and the National Institutes of Health. So he assembled the first generation of exobiologists by recruiting people from diverse backgrounds, including Lederberg, Margulis, and a University of Illinois professor, Carl Woese.
When Margulis arrived at graduate school, the University of Wisconsin had just built a huge electron microscope, among the most powerful in the world. Through it, she could see things that had previously been invisible. Most notably, she observed tiny structures called mitochondria. There can be hundreds, even thousands, inside each cell in a complex organism, and their function is to convert food into energy.
Looking into the microscope, Margulis seized on an idea that had been floated much earlier but had never gained much currency: that these mitochondria—found in the cells of complex organisms, from humans and horses to honeybees—were remnants of once free-living bacteria. Even more important, the origin of eukaryotic cells—of all the “higher organisms”—had come with the merging, somewhere back in evolutionary history, of two simpler single-celled organisms. This symbiosis had created a new, more complex creature altogether. Margulis was soon on the path to showing how central that merger was—not just to individuals, but to evolution as a whole. After all, in this scenario, evolution occurred not gradually but through a big, sudden change.
Many biologists found the notion of symbiosis hard to accept. The writer David Quammen asked a scientist whether Margulis was “perceived back then as being radical or flaky.”
“Uh-huh,” the scientist said. “Right from the beginning I think.”
But her ideas were proved right by the methods of another odd man out who was also funded by NASA: Carl Woese. A biophysicist and microbiologist, Woese felt himself an outsider in biological science, unappreciated and on the sidelines. Francis Crick, James Watson, and a few others were the field’s stars. “I differed from the whole lot of them,” Woese wrote. While others obsessed about DNA, the grand molecule that carries the information of life, Woese instead fell in love with the skinny, single-stranded ribosomal RNA that took the rich information stored in DNA and made it into working molecules—the proteins of the living cell.
This molecule is the most conserved of all those in biology, meaning it can be found in every living thing and is likely to have existed for all the four billion years of life on Earth. If you were going to compare creatures to determine which came first and which were most similar, this would be the part to use. For big animals, comparing necks and limbs and other features worked pretty well to draw out distinctions, but for the rest of living things—which are microscopic and basically round or oblong—that approach was useless. So Woese and his team began to extract RNA from living organisms. They strung it out in bits on a sheet of wet plastic so that they could eventually compare the genetic sequences of microbes.
Woese thus pressed forward a new kind of “fossil record”—one that marked similarities and differences among certain key molecules. Diving into this record, he discovered an entirely new form of life, with genetic sequences unlike bacteria and unlike the eukaryotes that make up bigger creatures in biology. He and his colleagues eventually classified these unknown creatures into their own domain, called Archaea.
Margulis hadn’t worked with molecular fragments of organisms, as Woese had; she was up to her elbows in the slimy creatures themselves. Margulis and Woese were somewhat opposite characters. She was warm and social. Woese was fairly reclusive and shy; he had studied medicine for two years, then quit after the first two days of his pediatrics rotation. He could party with a few very close friends, but rarely. The two each had a bit of disdain for the other’s specialty. Margulis thought of molecular biology as sterile and divorced from real life. Woese thought of the creatures of biology as messy and confusing, not at the intellectual center of things.
But when it came to proving Margulis’s hypothesis that the mitochondria in humans and all other animals and plants were bacterial, it was Woese’s methods that gave the initial proof.
W. Ford Doolittle, a NASA-funded biologist at Dalhousie University in Halifax, was intrigued by Margulis’s work. “Her ideas didn’t seem all that flaky to me because there was some work already out there, even though it had come along decades before we had been born,” he said. With advances in gene-sequencing technology, he spotted an opportunity to answer the open question of whether mitochondria evolved from free-living bacteria. All a scientist needed to do was pinpoint the genetic sequence of mitochondrial RNA and then compare it with the sequences of bacterial RNA and of nuclear RNA. Which was it more like?
In the early 1970s, one of Woese’s lab members arrived in Halifax and joined Doolittle’s group. Linda Bonen was an expert in the new sequencing techniques—and in the ensuing years, her skills, along with help from another researcher, Michael Gray, would make such genetic comparisons possible. The work resulted in a number of papers, including one published in 1977 showing that the RNA in wheat mitochondria doesn’t resemble the RNA inside wheat’s nucleus. Instead, it resembles the RNA of bacteria. Essentially, years of doubt and debate ended at once. Margulis’s hypothesis was shown to be correct. In 1983 she won membership in the National Academy of Sciences, reserved for top-ranking scientists in the United States. She later won the highest honor in American science, the National Medal of Science.
This all came from a string of research by outside-the-mainstream scientists working with fresh NASA money, made possible by Sputnik. They remade the central theme of biology.
“There is a new biology,” said Doolittle, in a telephone interview from Nova Scotia. “It’s microbially oriented, rather than just animal- and plant-oriented.” As a student, Doolittle had learned about animals and plants. “We thought of bacteria as an afterword,” he said. “Now it’s clear that the world is microbial.” This shift, says Doolittle, is due to the pioneering work of scientists like Margulis and Woese.
All of this has put new opportunities in front of biology students and researchers. They now range all over the world, often visiting extreme environments, to seek out new bacteria and learn how they survive. One of the biggest projects in all of biology, the Deep Carbon Observatory, has completed its first 10 years of exploring relations between bacteria and the planet, with more than 1,200 scientists in 55 nations.
The wider public has caught on, too. Margaret McFall-Ngai, an animal physiologist and biochemist at the University of Hawaii, illustrated it: “If, getting on a plane, I make the mistake of saying I work on microbiology and human health,” she said, her seatmate will inevitably ask about the human microbiome. That subfield—devoted to the bacteria that live on and inside of us—is one of many with roots in the new biology. And McFall-Ngai can predict how the conversation will go: “I’ll be in for two hours of questions.”