fourteen dull brown birds that quietly demolished the idea species are fixed forever.
means a group of closely related finch species on the galapagos islands whose varied beak shapes, evolved to exploit different foods, became a founding case study in natural selection.
from darwin collected them in 1835 during the beagle voyage but barely noticed them, mislabeling several and lumping specimens by island instead of species; it was ornithologist john gould, back in london, who realized they were separate species descended from a common ancestor, a discovery that helped crystallize darwin's thinking on evolution years later.
large ground finch — crushes the toughest seeds with a nutcracker beak
woodpecker finch — uses a cactus spine as a tool to dig grubs
warbler finch — thin insect-picking beak, barely looks like a finch
vampire finch — on wolf island, drinks blood from booby seabirds