Question

Which of the following is not required for a behavioral trait to evolve by natural selection?

(A) In each individual, the form of the behavior is determined entirely by genes.

(B) The behavior varies among individuals.

(C) An individual’s reproductive success depends in part on how the behavior is performed.

(D) Some component of the behavior is genetically inherited.

Short answer

1. The statement “in each individual, the form of the behavior is determined entirely by genes” istrue.

2. The statement “the behavior varies among individuals” isfalse.

3. The statement “an individual’s reproductive success depends in part on how the behavior is performed” is false.

4. The statement “some component of the behavior is genetically inherited” is false.

Step-by-step solution

Ethology

Ethology is a discipline of biological science that focuses on animal behavior. Animal communication, behavioral patterns, and sociobiology are some of the significant broad subjects of ethology.

The behavioral study of animals in ethology is scientific and gives answers for complex natural phenomena. It also helps to understand the process of behavioral evolution in humans.

Explanation of option ‘(A)’

Innate behavior is independent of natural selection. It is present in an individual from birth. However, all the traits are inherited through the process of natural selection. When genes entirely determine the behavior, it does not get selected by nature again.

Therefore, when behavior is genetic, it does not require evolution by natural selection.

Thus, the statement is true.

Explanation of option ‘(B)’

Innate behavior is similar in a population and does not vary. The environment entirely determines adaptive behavior, and it differs among individuals. The different behaviors adapted by individuals are developed as per their necessity due to natural selection.

Therefore, distinct adaptive behavior in a population evolves by natural selection.

Thus, the given statement is false.

Explanation of option ‘(C)’

Adaptive behavior, which is developed eventually to increase relative fitness, undergoes natural selection. If the traits assist in the better adaptation of a population, those traits are transferred to the next generation.

Therefore, the components of genes responsible for behavioral traits and adaptive behavior evolve by natural selection.

Thus, the given statement is false.

Explanation of option ‘(D)’

The behavior which is developed later by the force of natural selection also transfers genetically as its components. The heritable traits or behavior only move to the next generation.

Therefore, the components of genetically inherited behavior are evolved by the force of natural selection.

Thus, the given statement is false.