 Often, these features (large horns, large size, specific pelts) are not only desirable to humans, but play roles in survival within the animal’s natural habitat and role within their ecosystem.By cutting down the number of animals bearing those desired phenotypes (and thus harboring the associated alleles), the amount of genetic material necessary for conferring those phenotypes upon later generations of the population is depleted (an example of genetic drift).This selection changes population structure over time, and can lead to a decrease in the wild-condition fitness of the population as it is forced to adapt around hunting-condition pressures.