LIFE SCIENCE

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OBJECTIVE LIFE SCIENCE

EVOLUTION

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
In whale flippers, we see the same bones that humans have in their arms, just in different proportions (length and size) as their mammal ancestors lived on land. This also demonstrates that we share a distant common ancestor with whales. These are known as what kind of structures?
A
Analogous
B
Homologous
C
Vestigial
D
Remnant
Explanation: 

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

Detailed explanation-2: -Whales, lizards, humans, and birds all have the same basic limb layout. But how did such different animals wind up with the same sort of limb? The answer is that they inherited it from a common ancestor, just as cousins might inherit the same trait from their grandfather.

Detailed explanation-3: -Cetacean flippers have the same bones as the forelimbs of other mammals. The humerus, radius, ulna, carpals, metacarpals and phalanges are all present. However, in cetaceans the radius and ulna (forearm) and humerus (upper arm) are fused. Thus, they don’t have elbows.

Detailed explanation-4: -Whales have arm, wrist & finger bones in their front flippers. This is the front flipper bones of a Grey whale.

Detailed explanation-5: -An example of homologous structures are the limbs of humans, cats, whales, and bats. Regardless of whether it is an arm, leg, flipper or wing, these structures are built upon the same bone structure. Homologies are the result of divergent evolution.

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