National Geographic : 2009 Feb
adapted individuals of each population survive to leave o spring and others don t. en he nur- tured, re ned, developed, and concealed that theory for 20 years, until a younger man named Alfred Russel Wallace (see " e Man Who Wasn t Darwin" in National Geographic, December 2008) struck upon the same idea, forcing Dar- win to rush to get his own ready for print. at was 1858. By then Darwin had begun writing a long, detailed, heavily footnoted trea- tise on natural selection, but it was only half nished. Panicked, feeling proprietary, yet also reawakened to the wondrous immediacy of the story he had to tell, he shoved the big book aside and quickly composed a more streamlined account. is shorter, slapdash version would be merely an "abstract" of the theory and its supporting data, he claimed. He called it "my abominable volume" because, a er decades of cogitation and delay, the writing process was so hurried and painful. He wanted to title it An Abstract of an Essay on the Origin of Species and Varieties rough Natural Selection, but his publisher persuaded him to accept something at least marginally more snappy. It appeared in November 1859, titled On the Origin of Species by Means of Natural Selection et cetera, and was a sellout success immediately. Five more editions went to print during Darwin s lifetime. Almost inarguably, it s the most signi - cant single scienti c book ever published. A er 150 years, people still venerate it, people still deplore it, and e Origin of Species continues to exert an extraordinary in uence---though, unfortunately, not many people actually read it. And the forgotten clues that led him to his theory are still largely forgotten. Anyway, they re omitted from the mythic account. Scholars still dispute the signi cance of those extinct and liv- ing Argentine creatures, especially the ground sloths and glyptodonts, the tree sloths and armadillos and rheas. Evidence is mixed, even among the various comments on the matter le behind by Darwin himself. e most telling of those comments, in my view, is one so conspic- uously placed that it tends to get overlooked. It comprises the rst two sentences of e Origin of Species, beginning the book on a nostalgic note. It says: "When on board H.M.S. Beagle, as natural- ist, I was much struck with certain facts in the distribution of the inhabitants of South Ameri- ca, and in the geological relations of the present to the past inhabitants of that continent. ese facts seemed to me to throw some light on the origin of species. ..." The finches of the Galápagos make their appearance about 400 pages later. j Fossils collected by Darwin of the giant ground sloth Megatherium had sharp teeth (above), vastly different from those of its living tree-dwelling cousins.