What do vestigial structure tell us about their ancestors? Give an example of a vestigial structure.
Vestigial structures are genetic remnants from ancestors that no longer serve a purpose in the current organism. These structures provide valuable insights into the evolutionary history of a species by suggesting ancestors had specific features that are no longer necessary in their descendants. Such structures are often considered as evidence of evolution.
An example of a vestigial structure in humans is the appendix. The appendix is a small, finger-shaped pouch located at the junction of the small and large intestines. In our ancestors, who likely had a plant-based diet, the appendix played a role in digesting cellulose-rich foods. However, with the evolution of a more omnivorous diet and changes in our gastrointestinal system, the appendix has become functionally redundant. In modern humans, the appendix has no known vital functions and can even become inflamed or infected, requiring its surgical removal (appendectomy). This vestigial structure suggests that our human ancestors had a physiological need for an appendix, but over time, it lost its significance and is now considered a vestige of our evolutionary history.