Origin of the species: where did Darwin's finches come from?

Galápagos finches have been the subject of a plethora of evolutionary studies, but where did the first ones come from?When the first of the Galápagos Islands arose from the ocean floor around 3m years ago, they were naked, angry, lava-spewing cones devoid of life. Now, millions of years later, they are alive with some of the world's most iconic animals. Giant tortoises. Sea iguanas. Flightless cormorants. And those finches equipped with Swiss army knife beaks.The Galápagos finches are probably one of the most well-known examples of evolution and will forever be tightly linked to Charles Darwin's voyage and his theory of natural selection (although you may be surprised to learn that the Galápagos finches were not as central to Darwin's theory as we like to think). With their diversity of bill sizes and shapes, each species has adapted to a specific type of food; the ground-finch (Geospiza) has a thick beak adapted to feeding on a variety of crunchy seeds and arthropods, whereas the warbler finch (Certhidae olivacea) developed a slender, pointy bill to catch tasty insects hiding between the foliage. The woodpecker finch (Cactospiza pallida) even uses twigs or cactus spines to pry arthropods out of treeholes. Continue reading...