Question

A bat wing, a primate arm, and the front leg of a cat all have similar bone structure where one bone is attached at the shoulder, two bones in the forearm, a series of wrist bones and digits. Based on this evidence, what conclusion can be drawn?
A. Cats, bats, and primates evolved in similar environmental conditions.
B. Cats, bats, and primates have common ancestors with the same bone configuration.
C. Gene flow has occurred between Cats, bats, and primates.
D. Natural selection favoured this bone configuration of animal groups.

Answer 1

Hint: A bat wing, a primate arm, and the front leg of a cat are the example of homologous structures. They differ in function but have similar structure.

Complete Answer:
- The organs which differ in function but are similar in structure are called the homologous organs. The difference in function is due to the adaptation with different uses but they share a common ancestry. They also share similarities between the DNA and protein sequences. Charles Darwin in 1859 stated that the organisms having common ancestry show a similar body plan.
- This type of evolution is known as divergent evolution. This occurs when two organisms are separated by geographical barrier. This exerts pressure and drives adaptation to the new environment. After many generations, the population becomes different and interbreeding is no more possible between them.

Thus the correct answer is (A). Cats, bats, and primates have common ancestors with the same bone configuration.

Note: The divergent evolution takes place due to predator or their absence, environmental factors. Darwin finches are an example of divergent evolution. Adaptation is the driving force for divergent evolution.