Question

Which of the following must exist in a population before natural selection can act upon that population?

A) Genetic variation among individuals
B) Variation among individuals caused by environmental factors
C) Sexual reproduction
D) B and C only
E) A, B, and C

Answer 1

A) Genetic variation among individuals.

Step-by-step explanation:

Natural selection is the process by which certain heritable traits become more or less common in a population over time. This process depends on the presence of genetic variation among individuals in a population. Without genetic variation, there would be no differences in traits for natural selection to act upon.