vestigial structure
Functionally obsolete anatomy
A vestigial structure is a body part that has lost most or all of its original function through evolution.
The human appendix, tailbone, and wisdom teeth are classic examples—organs that served purposes in ancestors but now do little or nothing useful.
Vestigial doesn't necessarily mean completely useless; some structures retain minor functions or have been repurposed.
The whale's pelvis is a vestigial structure from when its ancestors walked on land.
- living fossilOrganism unchanged since prehistory
- atavismReturn to ancestral type
- appendageProjecting body part
- nictitating membraneTransparent inner eyelid
- throwbackReturn to ancestral type
goosebumps · Darwinism · junk DNA · evolution · remnant · tonsils · wisdom teeth · outgrowth · dewclaw · obsolescence · body hair · third eyelid · tailbone · transitional fossils · comparative anatomy · rudimentary · relic · biology
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