Natural selection requires that variation exists in a population and that the variation
A) is generated by mechanisms other than mutation.
B) is heritable.
C) does not affect reproductive success.
D) is consistent across environments.

Question

Quizplus · Accepted Answer

Natural selection acts on heritable traits, so variation must be passed down from one generation to another in order to be subject to selection. Therefore, option B is the correct choice. The other choices are incorrect because:

A) Mutations can generate variation, so this is not a necessary condition for natural selection. 
C) Variation in reproductive success is precisely what natural selection acts upon, so this cannot be a condition for it. 
D) Variation can be specific to certain environments or arise as a result of environmental change, so consistency across environments is not a necessary condition.

Natural Selection Requires That Variation Exists in a Population and That