Question

Write the correct alternative:
(i) Vestigial organ ................................... present in human body is proof of evolution.

• A. \( \text{Human hand} \)
• B. \( \text{Appendix} \)
• C. \( \text{Ear muscles} \)
• D. \( \text{Tail-bone} \)

Hint:

Vestigial organs are reduced remnants of formerly functional structures; common textbook examples in humans include the appendix and the coccyx, while fully functional structures like the hand are not vestigial.

Answer 1

The Correct Option is B

Step 1: Define vestigial organ
A vestigial organ is a reduced or rudimentary structure in a living organism that has lost most or all of its ancestral function through evolution. Vestigial structures provide evidence that species have changed over time because they are remnants of organs that were functional in ancestral species.

Step 2: Examine each option with respect to vestigial status
(A) Human hand: The human hand is fully functional for grasping, manipulation, and sensation; it is not reduced compared with ancestral function, so it is not vestigial.
(B) Appendix: The vermiform appendix in humans is a narrow, blind-ended tube attached to the cecum. In many herbivorous ancestors and relatives, a larger cecal pouch and associated structures aided cellulose digestion. In humans the appendix is much reduced in size and has no essential role in digestion for the typical adult, making it a classical example of a vestigial organ and evidence of evolutionary change.
(C) Ear muscles: Some auricular (ear) muscles are present in humans and are sometimes considered vestigial because they are reduced and most people cannot move their ears voluntarily; however, they are less commonly cited as the standard textbook proof of evolution compared with the appendix.
(D) Tail-bone: The coccyx (tail-bone) is also a vestigial structure, being the remnant of a tail present in ancestral primates; it is a valid example of vestigiality.

Step 3: Choose the best single answer
Both the appendix and the coccyx are vestigial structures, but among the given options the appendix is the classical, unambiguous textbook example frequently used as direct evidence of evolution. Therefore option (B) Appendix is the correct single-best choice.