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, potentially increasing genetic variation as more individuals can survive and reproduce.
• A decrease in tuna fishing would mean more tuna survive, which could also lead to a larger population and potentially more genetic variation.
• A decrease in tuna predators would allow more tuna to live, again potentially increasing the population size and genetic variation.
• However, an increase in pollution can cause selective pressure. It may harm or kill certain individuals with specific genetic traits more than others. For example, some tuna may be more sensitive to pollutants in the water. If a significant number of individuals with particular genetic make - ups are affected (sick or die), the overall genetic variation in the population will decrease as those alleles are lost or become less common.

Answer:

an increase in pollution