Question

If extrinsic mortality is high, which of the following statements are correct?

1) Selection will act more strongly against mutations that negatively affect organisms late in life than early in life
2) Selection will act equally strongly on mutations that negatively affect organisms early in life and late in life
3) Organisms should age more rapidly than if extrinsic mortality was low
4) a and c are correct
5) b and c are correct

Answer 1

In high extrinsic mortality environments, selection acts more strongly against mutations that negatively affect organisms late in life and organisms age more rapidly.

Step-by-step explanation:

If extrinsic mortality is high, the correct statements are:

1. Selection will act more strongly against mutations that negatively affect organisms late in life than early in life: In high extrinsic mortality environments, organisms are more likely to die at a younger age. Therefore, mutations that negatively affect organisms later in life will have a greater impact on their reproductive success, leading to stronger selection against such mutations.
2. Organisms should age more rapidly than if extrinsic mortality was low: In environments with high extrinsic mortality, organisms are under increased pressure to reproduce quickly and at an earlier age. This results in a faster aging process and shorter lifespan.

If extrinsic mortality is high, selection will act less strongly on mutations affecting organisms late in life, and organisms should indeed age more rapidly. 2) Selection will act equally strongly on mutations that negatively affect organisms early in life and late in life and 3) Organisms should age more rapidly than if extrinsic mortality was low. Option 4 (is not accurate because selection will not act more strongly against late-life mutations—if death is likely due to external factors before old age, there's less evolutionary pressure against harmful late-life traits.