Question

select the explanation for why a phenotype is selected for in the first environment but selected against in the second environment.
the phenotype leads to higher rates of survival and reproduction in the first environment but lower rates of both in the second environment.
the phenotype makes it difficult to secure resources in the first environment but provides access to resources in the second environment.
the phenotype is caused by alleles that disadvantage the organism in the first environment but benefit the organism in the second environment.
the phenotype stands out to predators in the first environment but blends into the background in the second environment.
the phenotype is found as a low percentage of the population in the first environment and is found as a high percentage in the second environment.

Explanation:

Natural selection depends on how a phenotype affects an organism’s fitness (survival and reproduction) in a specific environment. A phenotype selected for increases fitness, while one selected against decreases it. This option directly links the phenotype’s fitness consequences to the selection outcome in each environment. Other options either reverse the effect (B, C, D) or describe population frequency (a result of selection, not the cause, in E).

Answer:

A. The phenotype leads to higher rates of survival and reproduction in the first environment but lower rates of both in the second environment.