What did Charles Darwin observe in finch populations on the Galápagos Islands off the coast of South America?

1 Answer
Dec 20, 2017

Finches on the Galapagos Islands showed a far greater variety of beak shapes and sizes than anywhere else.

Explanation:

John Gould identified the Galapagos species as belonging to an entirely different group of finches made up at least 12 different species.
The difference in their beaks shows a clear gradation from the very large to the very small.The beak vary such that the different species feed on different parts of their favourite food Opuntia.

Long beaked species feed by punching holes in the cactus,shorter beaked species tear at the base of the plant.

These morphological differences adapted to different conditions were one of the most crucial examples that helped Darwin to support his ideas on speciation and evolution.

They have been called Darwin's Finches in popular science.

https://en.wikipedia.org/wiki/Darwin%27s_finches
Lack, David. 1947. Darwin's Finches. Cambridge University Press (reissued in 1961 by Harper, New York, with a new preface by Lack; reissued in 1983 by Cambridge University Press with an introduction and notes by Laurene M. Ratcliffe and Peter T. Boag). ISBN 0-521-25243-1