Question

Assertion (A): A group of apes split into two smaller groups - one evolved into the modern gorillas, and the other into a chimpanzee - human ancestor.
Reason (R): Bipedal locomotion is advantageous because it frees forelimbs for more actions.

• A. Both A and R are correct and R explains A
• B. Both A and R are correct and R does not explain A
• C. A is incorrect but R is correct
• D. Both A and R are incorrect

Answer 1

The correct option is B Both A and R are correct and R does not explain A

The earliest primates are assumed to have evolved from the then common mammals like shrews. Some of the early primates evolved into monkeys. Some of these monkeys, further, became the common modern monkeys, while the relatives of monkeys which diverged from the common ancestor, evolved into primitive apes. A group of apes split into two groups - one evolved into the modern gorillas, and the other into chimpanzee - human ancestor. Then from this group, modern chimpanzees and humans parted ways and evolved into their modern forms. During the course of all this evolution, the forelimbs of apes got modified, resulting in bipedalism, which freed the forelimbs for more actions. However, this is not the reason for the evolution of apes into humans.