Questions: Which type of selection increases overall genetic variation in a population?

The answer is the first one: disruptive selection.

Explanation for each option:

1. Disruptive Selection: This type of selection increases overall genetic variation in a population. It favors individuals at both extremes of a trait distribution, leading to a bimodal distribution. By promoting extreme phenotypes, disruptive selection can increase genetic diversity within a population.

2. Stabilizing Selection: This type of selection reduces genetic variation in a population. It favors the average individuals and selects against extreme phenotypes, thereby maintaining the status quo and reducing variation.

3. Directional Selection: This type of selection can reduce genetic variation over time. It favors one extreme phenotype over others, causing a shift in the population's trait distribution in one direction. While it can initially increase variation by introducing new alleles, it often leads to a decrease in genetic diversity as the population becomes more uniform in the favored trait.

In summary, disruptive selection is the type of selection that increases overall genetic variation in a population.