Genetic Drift
Genetic Drift - The Bottleneck Effect The population starts off normally. Then a catastrophic event happens, a chasm opens up in the cats' habitat and swallows up a good chunk of the population. This chasm, as a result, erases all of the orange cat population. The orange cat population did not go extinct because they were not "fit" enough or "good" enough to survive, this was simply due to random chance. The grey or calico cats are not better adapted, they just got lucky they were not in the area where the chasm opened up in. By luck, the grey and calico cats survived. The not-so-lucky orange cats go extinct, which will change the allelic frequency of the population due to this random catastrophic event. This illustrates the bottleneck effect. Genetic Drift - The Founder Effect The population starts off normally. There is a dry river in between the high land, and the lowland. Some of the cats get curious and decide to wander off to the lowland to see what is ove...