A zombie apocalypse wipes out almost the entire human species before the zombie threat is eliminated. Only a group of 100 people who were at a family reunion on an uninhabited island survived. They returned to the mainland completely unaware of what had happened to everyone. Answer the following questions regarding the few survivors that now begin to rebuild the human population.

A straggler with green eyes stumbles into the last remaining human outpost. The green eye trait did not exist in the outpost before her arrival, but it does now. What is the name of this mechanism of evolution?

Genetic drift is an arbitrary procedure that can prompt enormous changes in populaces over a brief time frame. Arbitrary float is brought about by repeating little populace sizes, extreme decreases in populace size called "bottlenecks" and originator occasions where another populace begins from few people.

Genetic drift is the adjustment in the recurrence of a current quality variation in a populace because of arbitrary inspecting of living beings. The alleles in the posterity are an example of those in the guardians, and chance has a job in deciding if a given individual endures and imitates.