Heroic, on a molecular level

MATT RIDLEY’S “Francis Crick: Discoverer of the Genetic Code” is the latest volume in Atlas Books’ “Eminent Lives” series, whose previous books have celebrated, among others, Caravaggio, Beethoven, Thomas Jefferson and George Balanchine. Ridley, an accomplished science writer (“Genome,” “The Agile Gene”) with a doctorate in zoology from Oxford, is the perfect choice to write this first full-length biography of Francis Harry Compton Crick, whom he considers “the greatest biologist of the twentieth century.”

That’s a powerful claim, given the stunning advances in biology in the last century, which began with the modern synthesis of Mendelian genetics and Darwinian evolutionary theory and ended with the race to sequence the human genome, with plenty in between. There are other candidates. What’s extraordinary is that several of them -- James Watson, Sydney Brenner, Leslie Orgel -- were also Crick’s collaborators. Crick’s scientific interests were prodigious in their depth and range, and Ridley notes that “Crick’s intellectual technique, throughout his life, was a dyadic pairing, a long-running two-way conversation with a chosen friend, somewhere between an interrogation and a Socratic dialogue.”

Crick began his scientific life as a physicist, not a biologist. His early career was what Ridley kindly terms “unremarkable”: In 1937, he graduated with a second-class degree in physics from University College, London, having failed to win a place at either Oxford or Cambridge. He was a voluble enthusiast, with a “loud, peculiar laugh” and a bumptious self-confidence that irritated such worthy elders as Sir Lawrence Bragg, head of Cambridge’s Cavendish Laboratory, where Crick cut his teeth as a biologist. But, says Ridley, “the signs of brilliance were all there,” among them mathematical facility, a “precocious atheism” and an obsession with fundamental, physical fact.

His graduate studies were interrupted by World War II, and for a time Crick was a civil servant working for the Admiralty, first on defenses against the German mines in the Thames estuary and later on mines to blow up German ships. He turned to biology immediately after the war, determined, Ridley explains, “to do something heroic in science and, above all, to explode a mystery.” For Crick, that meant either deciphering the brain or exploring “the border between the living and the nonliving,” which by then was firmly situated in genetics.

At the time, no one knew what genes were made of. The genetic material was eventually shown to be deoxyribonucleic acid, but its structure and how it transmitted its information remained mysterious. In 1953, Crick and Watson solved the mystery by determining DNA’s double-helical structure, greatly aided by what Ridley calls Crick’s “remarkable and perhaps unique” ability to “visualise topology in three dimensions.” Unraveled, each of the two strands becomes a template for the formation of a duplicate gene. One of the most famous understatements in all biology is nestled in the short paper in the scientific journal Nature in which they announced their discovery: “It has not escaped our notice that the specific pairing we have postulated immediately suggests a possible copying mechanism for the genetic material.”

Watson’s and Crick’s paths would diverge. They were temporarily alienated because of Watson’s 1968 account of their efforts, titled “The Double Helix,” which opens with another famous sentence in the history of biology: “I have never seen Francis Crick in a modest mood.” Watson had sent his former collaborator several drafts, but they only provoked Crick’s wrath: “My objection ... is to the widespread dissemination of a book which grossly invades my privacy.... If you publish your book now, in the teeth of my opposition, history will condemn you.” History has not done so. “The Double Helix” is generally acknowledged as one of the most engaging science books of the last century and has sold more than a million copies. .

Ridley notes that what really bothered Crick was probably not the invasion of his privacy but what Crick saw as “the cheapening of their achievement. For all his bounce, he was a man who believed in seriousness.” For a while, Crick contemplated (half seriously) writing a book of his own as a riposte and got so far as the opening line: “Jim was always clumsy with his hands. One had only to see him peel an orange.” But the immediate success of “The Double Helix,” and Crick’s basic good nature, dispelled the animosity and the friendship resumed.

Having solved the gene’s structure, Crick, working now with Brenner, turned to the next puzzle: how to explain the relationship between the simple structure of DNA and the enormous complexity of the proteins of which life is made. Their work on the genetic code and the synthesizing of proteins from amino-acid sequences via DNA’s nucleic-acid partner, ribonucleic acid, resulted in what has become biology’s “central dogma,” usually rendered as “DNA makes RNA makes protein.”

With the secret of life illuminated, Crick -- now at the Salk Institute for Biological Studies in La Jolla -- turned to the brain. His Socratic partner in this endeavor was the neuroscientist Christof Koch, of Caltech. Together they searched for the neural correlates of consciousness, an explanation for consciousness being the last (or at any rate the latest) frontier in biology.

With his physicist’s training and adamant lifelong atheism, Crick may be the prime exemplar of relentless scientific reductionism, as the opening of his 1994 book on their efforts, “The Astonishing Hypothesis,” attests: “ ‘You,’ your joys and your sorrows, your memories and your ambitions, your sense of personal identity and free will, are in fact no more than the behavior of a vast assembly of nerve cells and their associated molecules.”

Ridley notes that the book’s success helped make consciousness studies respectable. Crick and Koch sidled up to the problem by focusing on the visual sense: What are the neural correlates of our perception of, say, color? This was a far cry from corralling the whole of our consciousness, but it was the pragmatic physical approach that mattered. Crick was still pursuing the larger question when he died at age 88, in the summer of 2004; Koch continues the pursuit.

Ridley sums up his nimble biography by musing on his subject’s genius. Crick “trained his mind to be exquisitely good at solving nature’s puzzles using logic, had the courage to take on the biggest problems, and threw himself exuberantly into the task....He would have liked to find the seat of consciousness and to see the retreat of religion. He had to settle for explaining life.” *