Read Online The Reluctant Mr. Darwin by David Quammen - Free Book Online

present, he needed to focus himself on immediate tasks and conserve strength. His volume on coral reefs would be published any month. He was offering an ingenious, well-supported explanation for how they are formed. Next he would do a book on volcanic islands. Both of those had been added to his original ambitious plan for the Zoology of the Beagle series. Eventually he would write three complete volumes of geological observations from the voyage, plus editing five volumes on the zoology. All this took time; years. Where did the days go? In his diary he tried to keep track. The coral reef book alone, Darwin figured, cost him twenty months of effort. That was spread across four years during which he had worked also on the Zoology , the Glen Roy paper, some other geological projects, and (marginally) transmutation, losing the rest of his workdays to illness. Being a husband, a father, and a householder also took time, notwithstanding the help supplied by a butler, a cook, a nurse for the children, and other servants, as well as Emma’s own indulgence of his detached, contemplative habits. In May, he and Emma bustled their gang off to Staffordshire for a vacation at her family home. After a month there, he shuttled over to stay with his father and sisters in Shrewsbury, leaving Emma and the kids behind.
    He had left his notebooks behind too, in London, but that didn’t stop him thinking. The holiday from other work became a chance to put something on paper about transmutation. During those summer weeks of 1842, amid Emma’s family and then his own, he found enough quiet hours to write a dense précis of his ideas and of the evidence and arguments he’d collected to support them. He worked in pencil. This “sketch,” as he called it, came to thirty-five pages. Unlike the notebooks it was carefully structured, moving from topic to topic in a way meant to build his case clearly and cogently; but like the notebook entries it was elliptical, with phrases and sentences suggesting much more (at least to him) than they actually said. It was an outline, an extensive one, of the book he intended to write.
    He began with the topic of variation among domestic animals, noting the obvious point that individuals differ slightly from one another in size, weight, color, and other ways. Because some of those differences are heritable, human breeders have been able to perpetuate and even amplify desirable traits by carefully selecting which animals to pair. With enough selection over long stretches of time, breeders even produced new races—speedy horses versus dray horses and tallow cows versus beef cows, for instance. This was the setup for Darwin’s crucial analogy.
    From variation among domestics he moved to variation among wild creatures, and to what he called here “the natural means of selection.” Variation in the wild might not be as common or as extreme as variation among domestics (so he thought), but under certain circumstances it did occur. What caused it? He didn’t know—and, for the present, that didn’t matter. Some of those variations, like the ones among domestic animals, were heritable. Given the inherent rates of population increase and the enormous excess of insupportable offspring, to which Malthus had awakened him, wild creatures would be subjected to an automatic sort of culling, based on their capacities to compete for survival and for mating opportunities. By now he had hit upon not just his analogy, with domestic breeding, but his chosen term: “natural selection.” The net result over thousands of generations, he wrote mutedly, would be to “alter forms.”
    He had described a physical mechanism (or at least, part of it) by which new species could be produced. But was there empirical evidence that they had been produced, one from another, through any such pageant of organic change? Yes, and in the second half of his draft he sketched that evidence,