Finch comic

Comic from Animals Have Problems Too:

The Galapagos finches (also called Darwin's finches) of course being the birds that helped Darwin formulate his theory of evolution by natural selection (although he didn't realize their significance until back in England with the help of an ornithologist). They are still under study by many, but notably Peter and Rosemary Grant which have shown beak size can rapidly change via natural selection in response to climatic changes.