The Black Bellied Seed Cracker,Pyrenestes,is a West African Finch

Essay

The black bellied seed cracker,Pyrenestes,is a West African finch.Within the same geographic region,two subspecies of the finch are found.One subspecies has a large beak,which is efficient at cracking the hard seeds of the sedge,Scleria verrucosa.The other subspecies has a small beak,which is more efficient at eating the soft seeds of the sedge,Scleria goossensii.What type of selection occurred to produce this situation? Explain what a population distribution graph would look like that would depict this type of selection.