Question

4.a - lesson 1: natural selection self check
which of the following are necessary for natural selection?
○ variation of traits
○ small population
○ large population
○ asexual reproduction

Explanation:

To determine the necessary factor for natural selection, we analyze each option:

• Variation of traits: Natural selection requires heritable variation in traits among individuals in a population. Different traits affect survival and reproduction, allowing some individuals to be more successful (selected) than others.
• Small population: Natural selection is more about differential survival/reproduction due to traits, not population size. Genetic drift (not natural selection) is more prominent in small populations.
• Large population: Population size alone isn’t a requirement. Natural selection can occur in any population with trait variation, though large populations might show selection more clearly over time, but it’s not necessary.
• Asexual reproduction: Natural selection occurs in both sexual and asexual populations, but variation (even in asexual populations via mutation) is key, not the reproduction type. Asexual reproduction doesn’t guarantee selection; variation is still needed.

So, variation of traits is necessary for natural selection.

Answer:

A. variation of traits