“Darwin’s finches” are a variety of small black birds that were observed and collected by British naturalist Charles Darwin during his famous voyage on the H.M.S. Beagle in the early 1800s. Years later, Darwin argued that subtle variations in their beak sizes supported his concept that all organisms share a common ancestor (a theory known as macroevolution). The finches, whose technical name is Geospiza, have since become classic evolutionary icons...