vestigial structures
Functionless inherited features
Vestigial structures are body parts that have lost most or all of their original function through evolution.
The human appendix, wisdom teeth, and tailbone are classic examples—remnants of organs that served purposes in our ancestors but now do little or nothing.
In biology, these structures provide evidence for evolutionary theory, since they reveal traces of an organism's ancestral history.
The whale's vestigial hip bones suggest it evolved from land mammals.
- nictitating membraneTransparent inner eyelid
- third eyelidTranslucent inner ocular shield
- wisdom teethFinal molars to erupt
- remnantWhat stays after most goes
- atavismReturn to ancestral type
appendix · spandrel · tailbone · male nipples · evolution · tonsils · gill slits · biology · goosebumps · body hair · dewclaws · embryology · leftover · functionless · morphology · living fossils · junk DNA · degenerate
- evolutionevolution, natural selection, mutation, adaptation, speciation
- biologycells, DNA, cell, biology, gene
- macroevolutionmacroevolution, speciation, extinction, fossil record, common descent