LIFE SCIENCE

Detailed explanation-1: -Structures that have no apparent function and appear to be residual parts from a past ancestor are called vestigial structures. Examples of vestigial structures include the human appendix, the pelvic bone of a snake, and the wings of flightless birds.

Detailed explanation-2: -Vestigial organs are organs, tissues or cells in a body which are no more functional the way they were in their ancestral form of the trait. It is authentication of evolution and hence, were helpful in explaining adaptation. Such a structure can arise due to gene mutation which causes a change in the proteins.

Detailed explanation-3: -Examples of vestigial structures (also called degenerate, atrophied, or rudimentary organs) are the loss of functional wings in island-dwelling birds; the human vomeronasal organ; and the hindlimbs of the snake and whale.

Detailed explanation-4: -The pelvic girdle connects the spine to the lower limbs. Therefore, it is not vestigial.

Detailed explanation-5: -Vestigial structures are anatomical structures of organisms in a species which are considered to have lost much or all of their original function through evolution. These structures are typically in a degenerate, atrophied, or rudimentary condition or form.