Get The Origin Of Species The Beak Of The Finch Gif. Over the past four decades, evolutionary biologists rosemary and peter grant have documented the evolution of the famous galápagos finches by tracking changes in body traits directly tied to survival, such as beak length. Darwin observed the galapagos finches had a graded series of beak sizes and shapes and predicted these species were modified from one original mainland species.

They saw which species of finch were more likely to survive during droughts and which finches thrived during the wet years. This illustration shows the beak shapes for four species of ground finch: Explain why you think the range of beak depths is equal to the difference between the largest and smallest beaks.

In particular, changes to the size and shape of the beaks have enabled the different species to specialise in different types of food:

It is the only member of the genus platyspiza. It is the only member of the genus platyspiza. Darwin observed the galapagos finches had a graded series of beak sizes and shapes and predicted these species were modified from one original mainland species. He mentions the beak of a woodpecker, which allows it to gather insects for food;