Evolution of Evolution — Text-only | Flash Special Report
The Mythology of Natural Selection
Darwin’s ideas were crafted and refined within communities in London, not in isolation on the Galapagos
By Jim Secord
Where did Charles Darwin become convinced of the truth of evolution? Certainly not in the Galapagos Islands, with its extraordinary animals and plants, but rather in the smoky, noisy world of early Victorian London.
The story goes that Darwin was so struck by the unique fauna of the Galapagos during his five year voyage aboard the HMS Beagle that he immediately abandoned his belief in the stability of species. More than that, it is often claimed that his observations of finches, the beaks of which vary from island to island, immediately led him to believe in natural selection. But these accounts of instant conversion are myths. During the long, boring months of Beagle’sreturn to England, Darwin’s doubts about species began to crystallize.
It was only after moving to London in 1837, that he became a convinced evolutionist. The significance of Darwin’s finds started to take shape when experts such as the bird man, John Gould, began to identify his Galapagos specimens. ;The different varieties of tortoises and mockingbirds provided powerful evidence of the relations between the Galapagos fauna and that of nearby South America. In geographical space, as in geologic time, closely allied species emerged successively and in order, just as they did in the fossil record. These relations, which impressed Darwin throughout the voyage, suggested that species were not specially created.
As for the Galapagos finches, during his brief stay, Darwin failed to notice the significance of the variations of birds found on different islands. In a brilliant piece of detective work, historian Frank Sulloway examined Darwin's specimens now held in the Natural History Museum in London. It turns out that Darwin had been skeptical of local reports that the finches varied, so back in London his labels had to be corrected as much as possible using the collections of his shipmates. So despite popular claims, evidence suggests the Galapagos finches were not the reason for Darwin developing his theory of natural selection.
Instead, the inspiration came when Darwin combined insights from his post-voyage inquiries into breeding-related reproduction and generation, with an understanding of economics-based population increase. At that time, London was a hotbed of discussion about new theories in the sciences, so it is entirely appropriate that the central theory of modern biology was elaborated in a dingy bachelor’s flat in a crowded city—the largest the world had ever known.
To imagine that natural selection emerged fully when the Beagle landed on the Galapagos not only minimizes the challenges Darwin faced, but also fails to recognize that even the greatest innovations in science depend upon others. Today the Galapagos are a marvellous laboratory for understanding evolution, but only because Darwin made them so.
Jim Secord is director of the Darwin Correspondence Project, professor of history and philosophy of science at the University of Cambridge and a fellow of Christ's College. He recently edited Darwin's Evolutionary Writings for Oxford University Press, including the full text of his autobiography.
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