Question

For natural selection to occur, which of the following must be true for a population of organisms?

• A. Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.
• B. The population must be occupying the same niche as another local population.
• C. Organisms in the population must be capable of sexual reproduction.
• D. Food resources must be limited.

Answer 1

Answer: (A)

Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.

Evolution takes place due to various reasons like natural selection, mutation, genetic drift. Phenotypic variations must be based on genetic variations rather than on varying environmental conditions. Sexual reproduction results in the genetic variation but does not affect the natural selection. Also, limited food resources may drive natural selection but is not the reason for natural selection to occur.

Thus, the correct answer is 'Phenotypic variations must be based on genetic variations rather than on varying environmental conditions.'