A Brief History of Creation (26 page)

Timiryazev had by then become known as one of the earliest Russian converts to Darwinian evolutionism. As a young man, he had even made a pilgrimage to Darwin's house in Downe not long after the publication of
Origin
. Told that Darwin was ill and not receiving visitors, Timiryazev had rented a room above the local pub. For a week, he returned every day to sit on Darwin's stoop until his hero finally granted him a pleasant afternoon of walking and conversation. Back home, Timiryazev became the country's most prominent advocate of Darwinian evolution, occupying a role in Russia similar to Huxley's in Great Britain.

For Timiryazev, Darwinian evolution was more than just a scientific theory. It was a revolutionary force, materialistic and atheistic, with implications that could be carried into social and political spheres. Such connections usually found their way into Timiryazev's spellbinding science lectures, and eventually cost him his position at Russia's most prestigious center of higher learning, Moscow State University. Listening to Timiryazev at the Polytechnic Museum turned Oparin into a devotee of the elder scientist's radical politics and evolutionary leanings.

Oparin was captivated by Timiryazev's stories about the great Charles Darwin. But there was one thing that nagged at him from the very first
moment he heard Timiryazev explain Darwin's concept of evolution. Darwin had simply skipped over what Oparin saw as the most important part of the materialistic theory of evolution: the origin of life. Later, when he became a professor, Oparin would tell his students that “Darwin had written the book, but it was missing the very first chapter.” This was a void Oparin would spend most of his life trying to fill.

O
PARIN WAS BARELY TWENTY
when World War I broke out, and he spent most of the war studying plant biology at Moscow State University. After graduating in 1918, he started a mentorship under the eminent plant biologist Aleksei Nikolaevich Bakh, who had become a legend among Russia's socialist revolutionaries. As an old-guard member of the leftist People's Will group that had assassinated Alexander II, Bakh authored the most iconic piece of propaganda produced during the Russian Revolution,
Tsar-Golod
(“Tsar of Hunger”), an eloquent denunciation of the Romanov dynasty and capitalism.

Oparin finally met Bakh in Moscow, shortly after Bakh's return from exile in Switzerland and about a year after the abdication of the last absolute monarch in Europe, Tsar Nicholas II. Vladimir Lenin had seized power in a coup that would be remembered as the Great October Socialist Revolution, and the streets of Moscow were abuzz with revolutionary workers and menacing groups of militia calling themselves Red Guards. Under the Bolsheviks, Bakh found himself gradually elevated into an important leadership role in postrevolutionary Russian science. He and Oparin founded the country's Russian Academy of Sciences' biochemistry institute. Bakh was named the director, followed by Oparin after his mentor's death.

Much of Oparin's early work revolved around food production, a huge priority in the chaotic first years of the regime and something Oparin threw himself into wholeheartedly. But Oparin never stopped working to find answers to that seminal question that had so intrigued him since he had attended Timiryazev's lectures: the origin of life. He wrote his first work on the subject in 1919, but it was rejected by state censors. In the years immediately following the October Revolution, much of the tsarist state
apparatus was initially left intact, including the censorship boards, which were still deeply sensitive to anything that might contradict the official line of the Russian Orthodox Church. Oparin would one day see that rejection as a boon. It enabled him to sharpen a more sophisticated argument and theory.

By 1922, Oparin was presenting those new ideas on the subject of the origin of life to Soviet scientific bodies. In 1924, he sat down to write a book that would lay out what had by then blossomed into a grand theory. Like Haldane, Oparin tackled the problem in a way that was fundamentally different from the approach his scientific predecessors had taken. Scientists like Thomas Huxley or Henry Bastian had worked on the assumption that the first life appeared on an Earth not so different from the Earth as it still was. And this process, they assumed, had happened rather quickly.

Oparin and Haldane, on the other hand, were searching for answers about something that had happened, they believed, at least many hundreds of millions of years in the past on a planet that could scarcely be recognized and under conditions they could only creatively imagine. But both men had a great deal of evidence that simply had not been available to earlier evolutionists. Even though the study of the origin of life had stagnated for the previous four decades, the understanding of the conditions under which the first life appeared had changed dramatically. For the first time, scientists were beginning to appreciate that the Earth was much older than any of their predecessors had imagined, and that life had existed on the planet throughout most of its history.

T
IME HAD ALWAYS BEEN
an enigma for Charles Darwin. He believed that the pace of evolution based on natural selection was extraordinarily slow, with species being transformed inch by inch through countless generations full of evolutionary dead ends and long periods of stagnation. It was hard to account for the evolution of the simplest microorganisms into complex species like human beings in a time frame that people could accept.

The problem persisted, even though Buffon's once-radical guess at the Earth's age seemed absurdly timid by Darwin's era. In the first edition
of
On the Origin of Species
, Darwin had given his own reckoning of the Earth's age. Like the estimates arrived at by Buffon and Ussher, Darwin's figure was exact almost to the point of being silly. He estimated that the Earth was 306,662,400 years old, a figure based on his assessment, from geological clues, of the age of southern England.

Darwin's estimate drew the scrutiny of the Irish physicist William Thompson, usually remembered by the title he acquired later in life, Lord Kelvin. Kelvin was one of the most accomplished and publicly revered scientists of the age. His role in building the first transatlantic telegraph had brought him enormous fame, fantastic wealth, and ennoblement. He had also helped formulate the first and second laws of thermodynamics, which he had used to produce his own estimate of the age of the Earth. Like Buffon's estimate, Kelvin's was based on how long it would have taken the Earth to cool to its present temperature. Because he was unaware of the process of radioactive decay, which accounts for much of the heat generated below the Earth's surface, Kelvin assumed that the Earth was a rigid sphere that had been cooling since its inception, and that he could judge its age by comparing the Earth's exterior temperature to those taken from its interior.

Three years after the publication of
Origin
, Kelvin postulated that the Earth was between twenty million and four hundred million years old, but he revised the estimate downward in the coming years, largely to correspond with his much lower—and now recognized as vastly wrong—estimates of the age of the sun. By 1897, he had settled on twenty to forty million years—“much nearer 20 than 40.” Thomas Huxley attacked Kelvin's methods as faulty, but even Darwin's own son, the astronomer George Darwin, had put forth a relatively low estimate of fifty-six million years, which he based on his calculation of how long it would have taken the Earth to settle into its current twenty-four-hour cycle of daily rotation. The Earth's age remained an important—and strongly contested—subject of debate through the end of the nineteenth century.

In the face of so much dispute about the true figure, Charles Darwin removed the reference to the Earth's age from the second and all future editions of
Origin
. The question puzzled him throughout his life and hindered acceptance of the slow process of natural selection as the principal
agent of evolution. Even Darwin's staunchest supporters conceded that natural selection would likely have required hundreds of millions of years, but such a time frame was difficult to reconcile with the best estimates of how long evolution would have had.

Then, a discovery in France set in motion a chain of events that upset all the assumptions about the Earth's age. In 1896, a year before Kelvin gave his final estimate, a French physicist named Henri Becquerel happened to leave a packet of uranium salts on a Lumière photographic negative. Later, Becquerel returned to find an image of the packet burned onto the negative as if it had been photographed. By placing objects between his uranium and the negative, he found he could produce images of anything. The only conclusion he could draw was that invisible rays of energy were being emitted from the rock. Three years later, Marie Curie discovered the elements polonium and radium. She coined the term “radioactivity” to describe the mysterious energy they emitted.

In a remarkably short period of time after the discovery of radioactivity, physicists developed methods to measure the age of rocks based on the decay of radioactive elements. Every rock is made up of chemical elements, some of which are present as a mixture of isotopes, atoms of the same element that have different numbers of neutrons in their nuclei. Some isotopes are unstable and radioactive, and they are constantly, albeit slowly, decomposing into new, lighter elements. The length of time it takes for half of those molecules to decay into a new element is called half-life. Though each rock is initially endowed with some ratio of the isotopes of its various component elements, over time some of these undergo radioactive decay to give new ratios. By measuring these ratios, geologists learned to calculate how much time had passed since the rock had formed. The process came to be called “radiometric dating.”

In 1907, the chemist Bertram Boltwood published the results of a radiometric study of twenty-six rocks, one of which he found to be a staggering 570 million years old. As radiometric techniques were refined, the age of Boltwood's oldest rock increased to 1.3 billion years. Other geologists were finding rocks even more ancient, including one from Ceylon that was 1.6 billion years old. It took until the middle of the twentieth century for most
scientists to agree on a figure for the age of the Earth of about 4.5 billion years. Even by the time of Oparin's return to Moscow, most scientists understood that the Earth was vastly older than anyone a century earlier would have imagined it to be.

Yet the question still remained of just how long
life
had existed on the Earth. Huxley had postulated that abiogenesis was extremely rare, something that may have happened only once and only by a confluence of conditions and chance that made it extremely unlikely to happen again. It was possible that Earth had been lifeless for most of its existence. This was, in fact, exactly what the incomplete fossil record seemed to suggest.

During the first half of the nineteenth century, geologists had to make do with fossils found in irregular settings caused by the coming together of ideal geological circumstances, and then only those exposed at the surface were easily examined, such as the fossils Darwin had found on the volcanic island of St. Jago. The industrial revolution began to change all that. As long canals were constructed throughout the British Isles, connecting ports and coal-mining regions to inland industrial centers, geologists were left with deep, clean gashes into the Earth exposing strata that had accumulated over eons. They began to appreciate that certain fossils were always found in certain stratigraphic layers, and never in others. They didn't yet know how old those layers were—such knowledge would come only with radiometric dating—but they did understand that certain layers were older than others.

Eventually, they divided the time represented by the different layers into two long eons. The shorter and more recent was called the Phanerozoic eon, Greek for the “age of visible life.” The Phanerozoic was subdivided into even shorter geological periods, the earliest of which was called the Cambrian, a name coined by Adam Sedgwick after “Cambria,” the Latin name for Wales, where many of the first samples from that period were found. The Phanerozoic was, in turn, preceded by the older and vastly longer—and less imaginatively named—
Pre
cambrian eon.

When Darwin wrote
Origin
, all of the fossils scientists had acquired came from the shorter, more recent Phanerozoic eon, which we now know comprises a mere 15 percent of the history of the Earth. He addressed
his dilemma in
Origin
: “If the theory [evolution] be true, it is indisputable that before the lowest Cambrian stratum was deposited, long periods elapsed . . . and that during these vast periods, the world swarmed with living creatures . . . why we do not find rich fossiliferous deposits belonging to these assumed earliest periods prior to the Cambrian system, I can give no satisfactory answer. The case at present must remain inexplicable.” The answer would eventually be found nearly a half century later and half a globe away, in the United States, where a young geologist named Charles Doolittle Walcott was fast becoming the most important fossil hunter in the world.

Raised in Rhode Island by a single mother, Walcott never finished high school and never spent a day in college. As a teenager, he had become a professional fossil collector, selling his finds to universities akin to the way Alfred Russel Wallace had once supported himself by collecting live specimens. At age twenty-six, Walcott was hired as the assistant to the chief geologist of the state of New York, James Hall, a man as famous for his tyrannical disposition as his expertise in paleontology—and he was very famous for his paleontology.

Hall let Walcott in on one of his most intriguing discoveries: a strange-looking reef in a riverbed near the town of Saratoga, decorated by round patterns imprinted on limestone, each about a meter wide. Hall was convinced that the shapes were biological in origin and that they had been left by colonies of millions of microscopic algae. He called his hypothesized microbes
Cryptozoon
, “hidden life.” The trouble was that he didn't have an actual fossil. Even in the twenty-first century, identifying a microscopic fossil is a painstakingly difficult task. Microbial cells are not that different in shape and size from all manner of natural nonliving particles. Since they have no skeleton, they do not fossilize well. Debate often hangs on contextual clues such as the type of environment where the surrounding rock was deposited and the ratios of various isotopes in elements such as carbon and sulfur, which can hint at the hand of biology. While modern micropaleontologists have sophisticated equipment for determining whether fossils are biological in origin, for Walcott and his contemporaries these techniques did not yet exist. There was little scientific acceptance of
the evidence for
Cryptozoon
being of living origin. Walcott needed better microscopic evidence.