What are vestigial organs? Explain with an example in digestive system of human body.

Explanation

The organs that are present in the rudimentary form and do not perform any significant function in certain organisms, but correspond to fully developed functional organs of other closely related organisms are called vestigial organs.
• These organs were well-developed and functional in their ancestors but became nonfunctional and rudimentary in the present living forms because of change in their mode of life. For example, monkey possesses tail due to its arboreal habitat.
Ancestral man also possessed tail.
Present-day man does not possess fully developed tail. But the rudimentary form of tail is there in the form of a tail bone composed of four fused vertebrae and some muscles attached to that. The presence of this rudimentary tail in man indicates the common ancestry of man and monkey.