ANATOMY

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 structures are remnants of organs or structures that had a function in an early ancestor. Ostrich wings are examples of vestigial structures.

Detailed explanation-3: -Vestigial organs are rudimentary anatomical structures that are retained in a species despite having lost their primary ancestral function. These structures often lack an apparent purpose, in contrast to the full functionality of these organs observed in closely related and ancestral species.

Detailed explanation-4: -Vestigial structures are often homologous to structures that are functioning normally in other species. Therefore, vestigial structures can be considered evidence for evolution, the process by which beneficial heritable traits arise in populations over an extended period of time.

Detailed explanation-5: -A vestigial structure is a feature that a species inherited from an ancestor but that is now less elaborate and functional than in the ancestor.