Vestigial

Vestigiality refers to genetically determined structures or attributes that have apparently lost most or all of their ancestral function in a given species, but have been retained during the process of evolution.

Definition and examples

In the context of evolution, a vestigial organ or attribute is one that has lost all or most of its original function in a species through evolution. Although structures called vestigial often appear functionless, a vestigial structure may retain lesser functions or develop minor new ones. In some cases, structures once identified as vestigial simply had an unrecognized function.

Examples of vestigial structures in humans include the appendix, wisdom teeth, and the coccyx, or tailbone. In other animals, vestigial structures can include the wings on flightless birds or the eyes of cave-dwelling creatures.

History

The concept of vestigiality dates back to at least Charles Darwin, who argued in On the Origin of Species that the presence of vestigial organs can be explained by evolution.

Controversy

The concept of vestigiality has been controversial since its inception, with some critics arguing that what are labelled as "vestigial" organs may simply have functions that are not yet understood.

See also

• Atavism
• Spandrel (biology)
• Evolution of the horse
• Human vestigiality

References

Vestigial Resources
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