Here's a breakdown:
* Vestigial: Relating to a part of an organism that has lost its original function through evolution.
Examples of vestigial structures include:
* The appendix in humans: While once thought to be useless, recent research suggests it may play a role in immune system development. However, it is still considered vestigial as its original function in digestion has been lost.
* The wings of flightless birds (like ostriches): They are remnants of wings that were once used for flight, but are now reduced and non-functional.
* The pelvic bones in whales: These bones are remnants of a time when whales had legs and walked on land.
It's important to note that the term "vestigial" is not always clear-cut. Sometimes, structures may have a reduced or altered function, but not completely lost.
