Ten species of Darwin's finches show differences in beaks and feeding habits.

• The vegetarian tree finch uses its heavy beak to wrench buds from branches.
• Other tree finches (including the woodpecker finch) and the warbler finch feed on insects.
• Most ground finches (except cactus finch) feed on various sizes of seeds.

Such variations are best explained by "descent with modification" from a common ancestor.