Myth 5 - That Darwin Converted to Evolutionary Theory During His Historic Galápagos Islands Visit

Summary

It is sometimes said that Darwin was converted to the theory of evolution by the striking evidence provided by his famous Galápagos finches, and, in this connection, that his historic visit to the Galápagos Islands had an immediate impact on his evolutionary thinking.  Such was not the case.  During his five-week visit to these islands in September and October 1835, Darwin was still under the spell of creationist thinking, so much so that he failed to label most of his Galápagos birds by island—information that was of vital importance for establishing that these species had arisen by geographic isolation on the different islands of the Galápagos group.  Moreover, at the time Darwin collected the famous finches that are now named after him, he was misled by their remarkable beak diversity into thinking they were members of different avian families rather than being closely related descendants of a common ancestor. It was not until after Darwin’s return to England, and more particularly during Darwin’s fateful meeting with distinguished ornithologist John Gould in March of 1837, that Darwin finally became convinced that different species of birds indeed inhabited the different islands of the Galápagos group.  In addition, Gould’s astute correction of Darwin’s provisional voyage taxonomic assessments of the Galápagos finches allowed Darwin to grasp that these birds were members of a single avian subfamily. Inspired by this new information, Darwin realized that evolution could account for it, and he now generalized these conclusions to other aspects of his Beagle voyage collections.