AP BIOLOGY

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: -A vestigial structure is a biological structure that has lost a major ancestral function and is usually drastically reduced in size. Well-known examples include the eyes of blind cave fishes and blind cave salamanders, and the diminutive wings of kiwis and emus.

Detailed explanation-3: -adjective. ves·ti·gial ve-ˈsti-jē-əl.-jəl. Synonyms of vestigial. of a body part or organ : remaining in a form that is small or imperfectly developed and not able to function : being or having the form of a vestige (see vestige sense 2)

Detailed explanation-4: -Often, these vestigial structures were organs that performed some important functions in the organism at one point in the past. However, as the population changed due to natural selection, those structures became less and less necessary until they were rendered pretty much useless.

Detailed explanation-5: -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.