2. What is the effect of differential reproduction over time?

changes in a population's gene pool

the overproduction of beneficial traits

interbreeding of two or more populations

the disappearance of beneficial alleles

The correct answer is - changes in a population's gene pool

Explanation:

Differential reproduction suggest that those organism who are well adapted to there environment and reproductive fit are more likely to survive till reproductive age and are more likely to produce their offsprings.

So only those genes will pass to the next generation which is more suited to the environment and the less adapted genes will disappear over time due to differential reproduction.

Therefore if some genes are lost over time by loss of less reproductive suitable individuals of a population then their gene pool also changes because the gene pool is the sum of all the genes found in a population.

Therefore the correct answer is-changes in a population's gene pool.

A - Changes in a population's gene pool. That's your answer.