Question

Which environmental factor would likely lead to an increase in genetic variation in a population of squirrels?
an increase in predators
an increase in available food
an increase in forest fires
an increase in pollution

Answer 1

An increase in pollution.

Explanation: Many pollutants are mutagens (or increase mutation rates), which produces new genetic variants. The other options (more predators or forest fires) tend to cause stronger selection or population bottlenecks that reduce variation, and more food doesn't by itself create new genetic variation.