What are darwin's finches?

Charles Darwin is known as the father of evolution. When he was a young man, Darwin set out on a voyage on the HMS Beagle to Galapagos Islands. He collected several finch species, including the warbler finch, sharp-beaked finch, ground finch, small tree finch, large tree finch, common cactus finch and large ground finch.These birds, although nearly identical in all other ways to mainland finches, had different beaks. So, he wanted to soldify his idea of natural selection.