I'm looking for a commonly used term to describe a trait that has clear current utility but an evolutionary origin that is uncertain and that we do not necessarily wish to emphasize in our description (e.g. to avoid unnecessary speculation):

  • Adaptation emphasizes an origin driven by natural selection.
  • Exaptation emphasizes an origin driven by co-option.
  • "Aptation" fits the bill, but it seems cryptic and rarely used.

Thank you for your help.

  • 4
    $\begingroup$ Can you give an example of such a trait? It's not clear to me what you are describing? $\endgroup$
    – kmm
    Jul 11, 2018 at 18:59
  • $\begingroup$ I have rephrased the question to make it more precise. A vast number of traits have some function but an uncertain evolutionary history (that we often do not wish to emphasize). $\endgroup$
    – Akim
    Jul 11, 2018 at 21:10
  • $\begingroup$ @kmm, maybe woman breasts? It's still unclear why are they prominent. But that's only if "being sexually succesful" counts as current utility. $\endgroup$
    – rus9384
    Jul 11, 2018 at 21:42
  • $\begingroup$ Intelligent design. $\endgroup$ Jul 18, 2018 at 20:05

1 Answer 1


As you point out, people have sampled other terms like "aptation" but these terms are not commonly used.

In order to not imply anything about the evolutionary history, since it is unknown, I think it makes most sense to refer to these simply as traits or phenotypes (or genotype for that matter, depending on the approach you are taking). If you wish to emphasize that these traits are beneficial to the organism, it is sufficient to call them beneficial traits or use other adjectives like useful, positive, etc.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.