Final Answer:
The statement that is not necessary for the selection of one phenotype over another to lead to evolutionary change is option D. The phenotypes are not affected by the environment.
Step-by-step explanation:
Natural selection, a driving force of evolutionary change, relies on specific conditions. Options A, B, and C are crucial for selection to occur.
A states that phenotypes must differ in reproductive success, a fundamental principle of natural selection. B emphasizes the importance of selection being strong enough to counteract opposing forces like drift, migration, and mutation. C underscores the need for phenotypic differences to be caused by heritable genetic variation.
However, option D, stating that phenotypes are not affected by the environment, is not essential. In reality, environmental factors can influence the expression of phenotypes, impacting their survival and reproductive success.
Therefore, option D is not a necessary condition for evolutionary change through selection.
Option D is the answer.