A Brief History of Creation (31 page)

From a pocket in his space suit, Armstrong took out a collapsible rod with a bag at one end. He began scooping dust and a couple of small rocks from the ground below him, until the sample bag was packed full of gray-black powder. Even if something went awry and the moonwalk had to be aborted, the astronauts would at least return with this bag of what the scientists back at mission control called the “contingency sample.” After a series of other experiments, the astronauts went about a more discerning process of collecting what would be called the “documented sample.” A phone call from President Nixon had put them behind schedule, and they had to rush through what was supposed to be one of the most careful and deliberate phases of their excavation. Armstrong set about filling two more aluminum containers that the scientists had dubbed “rock boxes.” While Aldrin began hammering away at the surface with a core tube searching for a specimen that would provide scientists a picture of what lay just under
the moon dust that represented a kind of topsoil, Armstrong hurried about with a long pair of tongs, grabbing the rocks that looked most interesting.

Buzz Aldrin drives a core tube sampler into the lunar soil. Photographed by Neil Armstrong.

T
HE ASTRONAUTS RETURNED TO
Earth with 45.5 pounds of the lunar surface for the scientists at home, but there would be a delay before the business of serious study could begin. From the outset of the
Apollo
program, NASA officials had taken seriously Joshua Lederberg's warnings of contamination
from lunar bacteria. An elaborate quarantine center had been built at the Johnson Space Center in Houston, with a containment room for the lunar samples just down the way from the one that had been built for the astronauts themselves. In the case of the moon rocks, scientists had more to consider than the dangers of a lunar organism: contamination of the moon rocks themselves from microorganisms on Earth was a major concern, as it would taint the precious samples and could lead to misleading results.

Three weeks after the
Eagle
lifted off from the moon, the samples were ready to be parceled out for study by four research groups in NASA's exobiology program, each led by scientists who either had been or would be key figures in the search for the origin of life. Two of the teams were headed by scientists directly employed by NASA—one headed by geologist David McKay, who had personally trained Armstrong and Aldrin for their scientific work during their moonwalk; the other, by Sri Lankan chemist Cyril Ponnamperuma, who had become an important authority on the origin of life in NASA exobiology circles. A third box of samples was shipped off to UC San Diego, where they would be studied by a group led by Harold Urey, whose theories on the composition of the lunar environment had by then earned him the title “father of lunar science.” The fourth box of samples was delivered to the University of Miami, where it would be examined by a team headed by a colorful iconoclast named Sidney Fox, a six-foot-four chemist with a reputation as an absentminded professor, capable of spending hours in parking lots searching for his car and falling asleep in midsentence while standing up and delivering a lecture.

Fox's life story was almost as colorful as his personality. His father was a wig maker; his mother, a Ukrainian Jew who had fled tsarist Russia when she was just eleven years old, stowed away in a crate on board a steamship. Fox grew up in Los Angeles with a passion for music, particularly Benny Goodman–style big-band jazz and Broadway musicals. In his twenties, he dabbled in composing. While studying chemistry at UCLA, he even wrote the scores for several of the university's well-received annual musical revues. In 1935, he received a phone call from Walt Disney Studios asking whether he would be interested in composing the score for a movie based on an old Brothers Grimm fairy tale. It was going to be called
Snow White and the Seven Dwarfs
.
Fox was enthralled, but first he sought out the advice of his mentor at UCLA, a professor named Max Dunn. “You are going to make a choice between music and chemistry,” said Dunn. “And it is going to be chemistry.”

After UCLA, Fox moved to the California Institute of Technology. Founded in 1891 as a vocational school, tiny Caltech had, in a few decades, transformed itself into a world-class scientific research institution. Despite its relatively small size, as of 2015, Caltech scientists had won thirty-four Nobel Prizes, and the university had the distinction of having the highest faculty citation rate in the world. Even by the time Fox arrived in the 1930s, it had attracted some of the most important scientific minds in the United States to its faculty, including two who were making remarkable strides toward understanding the way living things work on a subcellular level: the chemist Linus Pauling and the biologist Thomas Hunt Morgan. Pauling was a pioneer in quantum chemistry and, in later years, would become one of the key elaborators of the molecular structures that make up living cells. Morgan had won fame as an evolutionary biologist who had just won a Nobel Prize for discovering, in fruit flies, the precise role that chromosomes play in genetic inheritance. Both men exerted a strong influence on Fox and the shape of his future scientific work.

At Caltech, Fox began to take a keen interest in evolution, particularly the prebiological history that resulted in what he often called the spontaneous appearance of the first life-forms. Fox was ambitious. He wanted to work in a field that would allow him to make a real impact. To Fox, the question of the origin of life was the central biological problem, precisely the sort of question that so many other scientists avoided and nobody seemed close to being able to answer. It was also a question that enabled him to forge new ground and challenge long-held assumptions of the scientists who came before him. Ironically, toward the end of his career, many scientists would end up accusing Fox of being stuck in scientific assumptions that were losing relevance to the understanding of the earliest life-forms.

A
S A PROFESSOR AT
Florida State University, Sidney Fox had become one of the more prominent origin-of-life scientists in the United States. He was
also one of the first to be drawn into the web of NASA's exobiology program, which was rapidly expanding along with the rest of the agency. He had been asked by NASA to organize the first American scientific conference on the origin of life, the Wakulla Springs conference, where he had brought Haldane and Oparin together. Ever since, he had aggressively tapped into NASA funding, using it to establish the first exobiology lab in the country, the Institute for Space Biosciences at Florida State. When Fox moved on to the University of Miami in 1964, NASA funding helped him establish a freestanding research facility, the Institute of Molecular Evolution, where several luminaries in origin-of-life research would be trained over the next two decades.

Prior to the
Apollo 11
landing, most NASA scientists predicted they would find a bounty of organic compounds on the moon. Cyril Ponnamperuma had been particularly confident. As it turned out, the
Apollo
astronauts found a desolate landscape without a protective atmosphere provided by a planet like the Earth and shaped by billions of years of exposure to the sun. Though the lunar samples from
Apollo 11
were eventually found to contain small traces of amino acids, these were so scarce that it was hard to see them as significant. As Fox would later write, it was as if the surface of the moon had been “baked to a cinder.”

Fox wasn't terribly disappointed. Officially, his role in the space program was to look for traces of organic compounds, evidence that the precursors of life were strewn throughout the solar system. But his real interest in exobiology wasn't so much the possibility of life in space as it was what space could tell us about life on Earth. He was looking for clues to how life might have begun on Earth, as he put it, “to test proposed concepts of steps leading to the emergence of life.” By the time of the
Apollo 11
mission, Fox had already come to believe that his laboratory experiments had shown the next crucial step in the evolution from amino acids to full-fledged proteins, and that he had solved the riddle of what Haldane would have called the “half-living” stage in the evolution of a living cell might have been like.

From the beginning of his experimental work on proteins, Fox had had his share of detractors. By the time of
Apollo 11
, those critics had grown numerous. Scientific understanding of the molecular composition of living
cells had grown exponentially in the decade and a half since the famous Miller-Urey experiment, and those advances were undermining Fox's conception of the earliest life-forms.

Like almost everyone in the field by then, Fox believed that a full-fledged living cell had not simply appeared fully formed on the primitive Earth. It had become apparent that simple
components
of living cells must have arisen first, which could then begin the long evolutionary process that would produce cells as we know them today. But which crucial component had it been? In many ways, this was the same problem faced by Fox and other scientists in the NASA exobiology program as they looked for microscopic life on other worlds: what was it about living cells that actually made them
alive
?

I
N 1944
, the Austrian theoretical physicist Erwin Schrödinger wrote a book called
What is Life?
The question was an old one. Even the most primitive ancient peoples noticed the differences between plants and animals and the inanimate world about them. The vitalists of earlier centuries had been captivated by the question of what exactly that difference was, or at least what caused it. But few had ever sought to really quantify the problem as Schrödinger had, and his book generated a great deal of excitement in the scientific world.

Schrödinger was a physicist, and a very successful one. His elaborations of quantum mechanics would eventually win him a Nobel Prize, and he approached the phenomenon of life as one might expect a physicist to. For him, the basic element inherent to all life was its ability to avoid the inevitable fate of all matter in the physical world: the decay into entropic chaos. A living thing does this by what Schrödinger described as “drinking order” from its environment: drawing in chemical elements and energy from the environment, and then transforming and rearranging them, via a functioning metabolism. But Schrödinger also singled out another factor in what made living things living: mutation, the replication with change that lies at the heart of the modern concept of evolution.

Schrödinger deduced that the basis of genetic inheritance must lie in
a molecule he called an aperiodic crystal. He chose a crystal because he believed that this molecule had to be ordered and stable, and thus able to persist over generations, which would not be true for a coacervate-like suspension. The crystal had to be aperiodic because he believed it would have to be able to store limitlessly variable information to allow for mutation and evolution. In other words, it had to be a single molecule structured in a way that atoms could store information.

Since the complexity of the first living thing must have stopped well short of a full-fledged cell, it stood to reason that some
part
of a cell had come first. The first half-living thing—what would come to be called a protocell—would have to have been able to do both of two things: metabolize using components of its environment and replicate with modification. Metabolism and replication were the same factors that Oparin and Haldane had singled out in their own hypotheses for the origin of life. The problem that would eventually arise was that these two functions are handled by different but mutually interdependent subsystems within the cell itself.

In later years, it would usually be described as the chicken-or-the-egg paradox of the origin of life. But in the mid-twentieth century, when Miller and Urey had reinvigorated the field with their experiment at the University of Chicago, it was a problem that hadn't yet reared its head. Though the workings of enzymes that govern metabolism were becoming well understood, little was concretely known about chromosomes. Since Thomas Hunt Morgan's elucidation of the chromosome's role in genetic inheritance, it had been clear that chromosomes play a central role in the functioning of genetics. But no one yet understood what they were actually made of. It was reasonable to assume that replication was handled by the same part of the cell that governed metabolism, that the chicken and the egg were the same thing. The reality was that scientists didn't yet really know all that much about cells.

T
HE CELL PROVIDES
one of the strongest pieces of evidence of the deep evolutionary connection between all life on Earth. Just as Geoffroy Saint-Hilaire
had seen the similarities in such seemingly different appendages as a bird wing and a human hand, microbiology, as it became more sophisticated, revealed equally compelling similarities in the structures of living cells of diverse organisms. The structures, the functions, even the language of genes, are too similar for cells not to have originated from the same cellular ancestor.