NEET BIOLOGY

Detailed explanation-1: -So, the correct answer is ‘They share a common ancestor’.

Detailed explanation-2: -Did you know that humans, birds, and bats have the exact same types of bones in their forearm? These organisms share the same forearm bones because they all evolved from a common ancestor. Human, bird, and bat forearm bones include the humerus, ulna, radius, carpals, metacarpals, and phalanges.

Detailed explanation-3: -But beneath the skin, the forelimb bones of these animals are startlingly similar. These likenesses in structure, called homologies, are the result of descent from a common ancestor.

Detailed explanation-4: -Whales, bats, cheetah and human share similarities in the pattern of bones of forelimbs. Though these forelimbs perform different functions in these animals, they have similar anatomical structure – all of them have humerus, radius, ulna, carpals, metacarpals and phalanges in their forelimbs.

Detailed explanation-5: -The upper forelimbs of humans and bats have fairly similar skeletal structures, whereas the corresponding bones in whales have very different shapes and proportions. However, genetic data suggest that all three kinds of organisms diverged from a common ancestor at about the same time.