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 allow more tuna to survive and reproduce, potentially increasing genetic variation as more individuals contribute to the gene pool.
• A decrease in tuna fishing would mean more tuna survive, which could also lead to an increase in genetic variation as the population size is larger and more individuals can pass on their genes.
• A decrease in tuna predators would result in more tuna surviving, similar to the above cases, and may increase genetic variation.
• An increase in pollution can cause selective pressure. It may harm or kill many tuna, especially those that are less resistant. If only a small subset of the population (those with certain genetic traits that make them more resistant to the pollution - related stress) survives and reproduces, this reduces the overall genetic diversity in the population.

Answer:

an increase in pollution