Question

which environmental factor could lead to a decrease in genetic variation in a population of tuna? an increase in pollution; an increase in food availability; a decrease in tuna fishing; a decrease in tuna predators

Explanation:

To determine which environmental factor decreases genetic variation in tuna:

• An increase in pollution (e.g., toxins) can harm or kill tuna, reducing population size and genetic diversity (bottleneck effect).
• An increase in food availability would likely support population growth, increasing genetic variation.
• A decrease in tuna fishing or predators would reduce mortality, allowing populations to grow and genetic variation to increase.

Answer:

an increase in pollution