Individual characters/Population sizes

Individual characters of animals affect their population sizes. This can be seen in the studies of Darwin during his stay at the galapagos islands. He studied finches in all the islands and he saw that the finches had different characteristics because they had to adapt to the environment around them. So for certain islands, only a certain kind of finch with features and characteristics that fit the surroundings would be found in a large population while other finches would have low or no populations in those areas.