Question

which of the following is least likely to change the gene pool of a population of chipmunks?
a pesticide poisons and kills a large number of chipmunks.
a group of chipmunks moves to a new habitat.
a number of chipmunks die due to old age.
a genetic mutation causes some of the chipmunks to have larger eyes.

Explanation:

• Option A: Pesticide poisoning and killing a large number of chipmunks can lead to a change in the gene pool as it may disproportionately affect certain genotypes (e.g., if some chipmunks have a genetic trait that makes them more vulnerable to the pesticide).
• Option B: A group of chipmunks moving to a new habitat (emigration) can change the gene pool of the original population as the alleles carried by the emigrating individuals are no longer in the original gene pool.
• Option C: Chipmunks dying due to old age is a natural part of the life - cycle. If it is a random process (not related to any genetic disadvantage), it is least likely to change the gene pool. The gene frequencies remain relatively stable as there is no selective pressure based on genetics.
• Option D: A genetic mutation introduces new alleles into the population, which will change the gene pool.

Answer:

C. A number of chipmunks die due to old age.