Question

During drought years on the galapagos, small, easily eaten seeds become rare, leaving mostly large, hard-cased seeds that only birds with large beaks can eat. if a drought persists for several years, what should one expect to result from natural selection?

Answer 1

One would expect the population of small beaked birds to decline much more than the population of large beaked birds due to starvation. With this change in population ratios, the next generation of birds will have a higher percentage of large beaks. So because of natural selection, the ratio of large beaked birds compared to small beaked birds will increase.