Question

In the Pleistocene period 10,000 years ago, there was a remarkable extinction of vertebrates in many continents, which may explain why the cheetah has famously low levels of genetic variation. Which evolutionary mechanism does this reflect?

A:natural selection
B:bottleneck effect
C:founder princable

Answer 1

B - Bottle neck effect. Caused by a large number of a population of die, leaving only a few individuals. These few individuals are the only ones left to pass on their genetic material and hence the genetic variation in that population is greatly decreased.

Founder principle/effect is when a small group of a large population get geographically separated (e.g. a 50 birds of a population of 500 get blown off course while migrating at settle on island previously uninhabited by the birds). The two new populations then begin to speciate. Note that here, the original population remains.

Your question talks about extinction and has no mention of another species very similar to the cheetah elsewhere in the world. Therefore, your answer is B.

(Note it's not A because natural selection increases genetic variation. Do you want me to explain what natural selection is or do you know that already?).