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Vestigial Organ


Degenerated organ; Remnant; Rudiment; Rudimentary organ; Vestige


Anatomical structure that has lost its original function in a species during the course of evolution.


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. The term “vestigial” was first utilized by Wiedersheim (1895) for use in the context of rudimentary structures that serve no apparent function. Archetypal examples of vestigial organs include structures such as wings in nonflighted birds, eyes in blind species, and vestigial limbs in snakes. Organs often become vestigial when selection for their original function becomes relaxed. They range from disadvantageous to selectively neutral to slightly advantageous (Gould 1980). Vestigial organs may be more...

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Smith, H.F., Wright, W. (2018). Vestigial Organ. In: Vonk, J., Shackelford, T. (eds) Encyclopedia of Animal Cognition and Behavior. Springer, Cham.

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