Tuesday, December 28, 2010

The Finches of Darwin

I came across someone unfamiliar with the story of Charles Darwin on the Beagle in 1831 and his trip to Galapagos, so I thought I'd post on that.

The birds on Galapagos are very similar in structure, and provided Darwin inspiration for his Theory of Natural Selection. At the time they were called Finches, but Moderns call them Tanagers. They are clearly similar in features and color. Natural selection provided slight differences in bills that allowed them to eat from a variety of food sources.



In 1845, Darwin wrote, "Seeing this gradation and diversity of structure in one small, intimately related group of birds, one might really fancy that from an original paucity of birds in this archipelago, one species had been taken and modified for different ends".


I can't say it better than Darwin did.

Darwin's Tanager - by John Gould who
was on the Beagle with Darwin
Darwin's tanagers are not actually an example of speciation, but rather, they are can all still interbred. This is an example of a species with huge variety of traits. This provides huge flexibility and adaptability wthin the population.