Question

Why would a diverse population be more resistant to disease, predation, and invasion?

Answer 1

A diverse population means a variety of genetic traits within the population. Certain traits are things that would get one group killed faster in any of these events. Let's say that you have a group of antelope with short legs while another group has long legs. Imagine these two groups being chased by hungry cheetahs. The group with short legs would most likely die because they wouldn't be as fast as the group with long legs. Since the whole species did not have the short legs trait, they did not all get wiped out and the species is able to live on and hopefully pass on the long legs trait to avoid predators.