"the first species of finch to inhabit the galapagos islands thousands of years ago was most likely an insect eater. today, finch species on these islands feed on a great variety of plants and animals. one early event that probably occurred that led to this feeding diversity was that
(1)members of the ancestral finch species had to decide if they would be better off feeding on seeds rather than on relatively scarce insect species
(2)some of the finch ancestors were born with beaks that were different from the beaks of other finches, and could eat both insects and seeds
(3)some members of the ancestral species that fed on insects began to die off, leaving few offspring
(4)another species of bird, a seed eater, arrived on the islands and began to breed with members of the ancestral species"