Concept explainers
Whale skeletons contain nonfunctional pelvic bones
a. as a result of convergent evolution.
b. due to catastrophism.
c. because whales evolved from ancestors that had hind legs.
d. because the bones might be needed for a future adaptation.
Introduction:
The vestigial can be referred to a rudimentary structure present in the body of an organism, which does not have any prominent function. These structures were functional in the ancestors of the organism, but during the course of evolution, the organism loses its function.
Answer to Problem 1MC
Correct answer:
The pelvic bone in the whales is a vestigial organ, which had a function in their ancestors, having hind limbs.
Explanation of Solution
Explanation for the correct answer:
Option (c) is given that the nonfunctional pelvic bones are present in whale’s skeleton as whales evolved from the ancestors that had hind legs. The whales are known to evolve from the Pakicetus. These organisms had four legs, and the hind limbs were functional. During the evolution, the hind limbs were lost, but the pelvic bone is still present in the whales. Hence, option (c) is correct.
Explanation for the incorrect answers:
Option (a) is given that the nonfunctional pelvic bones are present in whale’s skeleton as a result of convergent evolution. The convergent evolution can be defined as the process, in which the closely related species independently evolve the similar structures or traits to adapt to the environment. However, the pelvic bones were present in the ancestor of the whales, this is not evolved. So, it is an incorrect option.
Option (b) is that the nonfunctional pelvic bones are present in whale’s skeleton due to catastrophism. The catastrophism referred to a change, which occurs suddenly in the organism. However, the pelvic bones are not suddenly developed in the whales, it is not an example of catastrophism. So, it is an incorrect option.
Option (d) is because that the nonfunctional pelvic bones are present in whale’s skeleton might be needed for a future adaptation. The bones of the pelvis were functional in the ancestors of the whales. This is not evolved for the future adaptation. So, it is an incorrect option.
Hence, options, (a), (b), and (d) are incorrect.
Thus, it can be concluded that pelvic bones are a vestigial organ in whales. These were functional in their ancestors, but in whales, they are nonfunctional.
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Chapter 15 Solutions
BIOLOGY:LIFE ON EARTH-W/ACCESS
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