Chapter 18, Problem 1TYU

Evolution is based on which of the following concepts? (a) organisms share a common origin (b) over time, organisms have diverged from a common ancestor (c) an animal’s body parts can change over its lifetime, and these acquired changes are passed to the next generation (d) a and b (e) a, b, and c

Summary Introduction

Introduction: Evolution is a process that has been occurred since the origin of life. Species have evolved themselves according to their needs with their changing environment. To explain these changes taking place in different species of plants and animals, different theories have been put forward from time to time. The most accepted theory in modern science is that of Charles Darwin.

Answer to Problem 1TYU

Correct answer: During evolution, organisms have emerged from some common ancestors and with the course of time, due to many factors, have diverged from each other to form new species. Hence, the correct answer is option (d).

Explanation of Solution

Reason for the correct answer:

Evolution is a process of continuous improvement in a population according to their need in their natural habitats. Studies have shown genetic similarities between distant living species indicating that their genome has some common origin. Molecular studies have shown ancestral similarities in different species.

Option (d) is given as, “a and b”

Different species have emerged from one or a few common origins and with changing natural environment, have diverged themselves from the ancestral species to form completely new species. Hence, the correct answer is option (d).

Reasons for incorrect answers:

Option (a) is given as, “organisms share a common origin”.

Different species share common origin during the course of evolution, but many other factors also play a major role in evolution to take place. Hence, option (a) is incorrect.

Option (b) is given as, “over time, organisms have diverged from a common ancestor”.

Organisms evolving from common ancestors have adapted according to their changing environment. Along with common ancestry, other factors have also played crucial role for evolution to take place. Hence, option (b) is incorrect.

Option (c) is given as, “an animal’s body parts can change over its lifetime, and these acquired changes are passed on to the next generation”.

During the evolutionary course, body parts of animals do not change, but the organism adapts itself according to its environment and it does not transfer to next generation until there is change in gametes. Hence, option (c) is incorrect.

Option (e) is given as, “a, b, and, c”.

Evolution is not caused by a change in body parts of an organism. Hence, option (e) is incorrect.

Hence, the options (a), (b), (c), and (e) are incorrect.

Conclusion

During evolution, organisms have originated from some common ancestors and with the course of time, due to many factors, have diverged from common ancestor to form new species.