Chapter 19, Problem 1TYU

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

1. A.    There is heritable variation among individuals.
2. B.     Poorly adapted individuals never produce offspring.
3. C.     Species produce more offspring than the environment can support.
4. D.    Only a fraction of an individual's offspring may survive.

Summary Introduction

Introduction:

Natural selection is an important process that leads to evolutionary changes. In this process, nature selects species that have a great survival ability in the environment and produces a high number of offspring. Natural selection is discovered by Charles Darwin. The mechanism of natural selection is based on the survival and reproductive success of the species.

Answer to Problem 1TYU

Correct answer:

Natural selection is not based on the statement “poorly adapted individuals never produce offspring”. Therefore, option (B) is correct.

Explanation of Solution

Reason for the correct statement:

Natural selection is a mechanism in which nature selects species that have a better survival ability or fittest to the environment and produce more numbers of offspring.

Option (B) is given as “Poorly adapted individuals never produce offspring”.

As the natural selection is not based on “poorly adapted individuals never produce offspring”, it is the right answer.

Hence, option (B) is correct.

Reasons for the incorrect statements:

Option (A) is given as “There is heritable variation among individuals”.

Natural selection is a key step in the evolution. The individuals having heritable variations fit to the environment and are selected. Hence, it is the wrong answer.

Option (C) is given as “Species produce more offspring than the environment can support”.

Nature selects the individual that produces a high number of offspring. Hence, it is the wrong answer.

Option (D) is given as “Only a fraction of an individual’s offspring may survive”.

Nature selects individuals who fit to the environment, only a fraction of an individual’s offspring fits to the environment. Hence, it is the wrong answer.

Hence, options (A), (C) and (D) are incorrect.

Conclusion

Natural selection is not based on an observation denoting “poorly adapted individuals never produce offspring”.