The Beagle finches

Finches (Geospizinae) collected from different islands in the Galápagos. These are all ‘type specimens’, that is, they are the individual birds from which the description of each species was originally established. On display in the University Museum of Zoology Cambridge

The various species of Galápagos finches, with their differently adapted beaks, confined to individual islands in the group, have become iconic specimens but were hardly referred to by Darwin himself. They are not mentioned in Origin of Species, for example, their value to Darwin probably being undermined by the inadequate labelling of the specimens and uncertainty as to exactly where each one had been found. Their importance as examples of adaptive radiation and of evolutionary processes has been acquired as a result of much distinguished work after Darwin’s own time. So pervasive is the ‘well known’ importance of the finches to Darwin that he is often credited with observations and discoveries made well after his death.  It is probable that Darwin was able to interpret the finches in the light of his evolutionary ideas, rather than the other way round.