Question

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

Explanation:

• An increase in food availability would likely support a larger population size, which could potentially increase genetic variation as there are more individuals contributing to the gene pool.
• A decrease in tuna fishing would also allow the population to grow, potentially increasing genetic variation.
• A decrease in tuna predators would lead to a more stable or growing population, which might increase genetic variation.
• However, an increase in pollution can cause selective pressures. It can harm or kill individuals, especially those with less resistance. If only a subset of the population (with certain genetic traits) survives, genetic variation decreases as many alleles are lost from the gene pool.

Answer:

an increase in pollution