Under these drastically changing conditions, the struggle to survive favored the larger birds with deep, strong beaks for opening the hard seeds. Smaller finches with less-powerful beaks perished.

The most characteristic feature of Darwin's finches is the diversification of beak morphology that has allowed these species to expand their utilization of food resources in Galápagos ...

The different finch species on the islands are closely related to each other, but show wide variations in beak and body size and feeding behaviour. In particular, changes to the size and shape of the ...

The paper, by S. Lamichhaneyat Uppsala University in Uppsala, Sweden, and colleagues was titled, "A beak size locus in Darwin's finches facilitated character displacement during a drought." ...