Question

Which of the following is not an observation or inference on which natural selection is based?

(A) There is heritable variation among individuals.

(B) Poorly adapted individuals never produce offspring.

(C) Species produce more offspring than the environment can support.

(D) Only a fraction of an individual's offspring may survive.

Short answer

1. The statement "There is heritable variation among individuals" is false.
2. The statement "Poorly adapted individuals never produce offspring" is true.
3. The statement "Species produce more offspring than the environment can support is false.
4. The statement "Only a fraction of an individual's offspring may survive" is false.

Step-by-step solution

Natural selection

The primary phenomenon that drives evolution is natural selection. It helps the population and individuals to adapt and survive better according to the environmental challenges. The other assisting forces are mutation, gene flow, and genetic drift. Natural selection works following the genetic processes by supporting the beneficial traits.

Explanation for option (A)

Genetic variations are one of the prime requirements that need to get passed onto subsequent generations. They must be inherited among individuals to produce a viable impact on the population.

Thus, changes must be heritable among individuals.

Therefore, the given statement is true, and hence it is the incorrect option.

Explanation for option (B)

The population undergoing evolutionary changes is subjected to genetic changes. The individuals who successfully adapt to the changes are well received by nature, while those that poorly adapt to the changes are less preferred by nature and are eventually eliminated. The poorly adapted individuals tend to produce lesser offspring.

Thus, the individuals who fail to adapt to variations can produce offspring.

Therefore, option b is false, and hence it is the correct option.

Explanation for option (C)

Species often produce more offspring to enhance the chances of survival. The phenomenon of overproduction supports the fact that most reproductively immature individuals do not attain sexual maturity. Therefore, to increase the species' chances of survival, a population that practices overproduction beyond the environment can support it.

Thus, species are able to produce more offspring in a limited environment.

Therefore, option c is true, and hence it is the incorrect option.

Explanation for option (D)

Not all offspring of every individual would survive. The limiting factors include food resources, shelter, and predation.

Thus, all offspring do not survive.

Therefore, the given statement is true, and hence it is the incorrect option.