A Chance Encounter, a Roll of the Dice
Professor Curtis Johnson’s new book examines the role of chance in Darwin’s work on evolution.
Just as Charles Darwin’s five-year voyage on the Beagle took his thinking in a completely new direction, Professor Curtis Johnson’s research on Aristotle and Darwin led him into unexpected territory.
It was a journey that culminated in Johnson’s new book, Darwin’s Dice: The Idea of Chance in the Thought of Charles Darwin (Oxford University Press, 2014).
Today the theory of natural selection—the idea that species evolve because of traits that increase their likelihood of surviving and reproducing—is the cornerstone of evolutionary theory. It is a notion that remains as threatening to religious fundamentalists today as it was in the 19th century. But even those Victorians who accepted the idea of evolution, but saw it operating according to a divine plan, would have a hard time swallowing Darwin’s other key realization: that the mechanism of natural selection hinges on variations that are as random as a throw of the dice. Parents produce offspring very similar to themselves, but not identical, and it is these variations that are subject to natural selection.
This was Darwin’s unique insight, one not shared by Alfred Wallace, the codiscoverer of natural selection. Darwin’s notebooks and his correspondence with other scientists reveal his excruciating awareness that the idea of random variation would be every bit as offensive to Victorian society as the suggestion that humans share common ancestors with great apes and chimpanzees.
Through careful examination of Darwin’s personal notebooks, his successive revisions to his published work, and his huge correspondence with his associates, Darwin’s Dice demonstrates that once Darwin became convinced of the critical role of chance variation in natural selection, he never deviated from this view. Instead, with each new edition of his breakthrough book, On the Origin of Species, Darwin took tremendous pains to ensure that the role of chance was described in a way that would be palatable to his contemporaries.
Darwin’s Dice is not just meticulously researched and lucidly argued, it is also enlivened by ample quotes from letters that show Darwin and his correspondents at their frankest. The evolutionary philosopher David Depew recommends the book “to anyone who wants to see a great mind wrestling with a great challenge.” Evolutionary biologist Michael Ghiselin calls it “a splendid analysis of the role of chance in Darwin’s philosophy as well as his science.” Amazon’s editors named it one of their Best Books of October 2014, and it has been excerpted at length in the popular online magazine Salon.com.
So how did Johnson, who is Lewis & Clark’s Dr. Robert B. Pamplin, Jr. Professor of Government, make the leap from political theory to evolutionary biology? Surrounded by the overflowing bookcases in his third- floor corner office in J.R. Howard Hall, Johnson reflects on the circuitous route that led him to Darwin’s Dice.
It began during a 2006 sabbatical, he recalls, when he decided to revisit Aristotle’s biological works. Johnson’s field of expertise is ancient Greek political theory, as reflected in his first two books, Aristotle’s Theory of the State (1990) and Socrates and the Immoralists (2005). But he notes that Aristotle’s scholarship delved into every area of human knowledge, and his observations of the natural world were “in some ways more significant than his work in ethics and politics.”
Reading Aristotle in the original Greek, says Johnson, “I got into his biology and I started to think to myself, ‘This is sounding a lot like Charles Darwin.’ Why would I know that? Because Lewis & Clark has a class for first-year students called Exploration and Discovery. And one year, I taught a section of the class that involved reading some of Darwin.”
On a quest to find references to Aristotle, Johnson began to scour the notebooks that Darwin started writing shortly after his return from the Beagle. The notebooks, says Johnson, are incredible. “Darwin didn’t expect them ever to be published, so I believe they reflect his most private thoughts at that time. He knew he was onto something that was going to be hot. And in 1838, he made a note that said, ‘Remind myself to read Aristotle to see if any of my ideas are very ancient.’ And guess what— he never did it!” (Not until decades later, at any rate, long after the publication of Origin.)
With Aristotle temporarily eclipsed, Johnson came under the spell of Darwin’s fertile mind, and he asked himself why Origin did not appear until 1859, more than 15 years after Darwin completed the notebooks that contained his key insights. “One of my book’s major arguments,” says Johnson, “is that he was working on how to formulate his theory—not to revise what the theory was, but how to express it.”
Johnson says he could readily see embarking on another book about Darwin, perhaps one devoted to his relationships with some of his more hostile critics, including the notoriously competitive paleontologist Richard Owen and the social evolutionist Herbert Spencer, from whom Darwin borrowed the unforgettable term “survival of the fittest.” Whether friends or foes, Darwin and his contemporaries were in constant contact. Johnson notes that the collected Darwin correspondence currently stands at 19 thick volumes—and the compilation process still isn’t finished. “There’s so much valuable material there,” says Johnson. “I’d love to read that stuff and to write about it.”