Which set of three conditions is necessary for natural selection to occur in a population?

• A. Individuals vary in heritable traits, more offspring are produced than can survive, and individuals with certain heritable traits leave more surviving offspring than others.
• B. The population is small, all alleles are dominant, and the environment remains constant over time.
• C. Traits are acquired during an organism’s lifetime, mutations are always beneficial, and all individuals have equal survival.
• D. All individuals are genetically identical, resources are unlimited, and mating is completely random.

Answer: (A)

Verified step by step guidance

1. Understand that natural selection requires variation in traits among individuals in a population. This means individuals must differ in characteristics that can be passed on genetically.
2. Recognize that more offspring are produced than can survive, creating competition for limited resources. This leads to a struggle for survival among individuals.
3. Identify that individuals with certain heritable traits have a higher chance of surviving and reproducing, thus leaving more offspring than others. This differential reproductive success drives natural selection.
4. Note that the other options describe conditions that do not support natural selection, such as no genetic variation, traits acquired during lifetime (not inherited), or unlimited resources.
5. Conclude that the necessary conditions for natural selection are: heritable variation, overproduction of offspring, and differential survival and reproduction based on traits.