Stated Clearly

The repurposing of old traits for new functions is so important in evolution (but so rarely taught) that scientists keep independently "discovering" and renaming it. The first 4 are synonyms. The last 3 are important special cases:

- Trait conversion (Charles Darwin, 1859)
- Preadaptation (George Gaylord Simpson, 1953)
- Co-option (I'm not sure who coined this or when)
- Exaptation (Stephen Jay Gould, 1982)
- Neofunctionalization (Hermann Joseph Muller 1936)
- Moonlighting (Constance J Jeffery, 1999)
- Recruitment (Refined in 2020 by Morgan Beeby et al.)

"Moonlighting" is when a trait still performs both the old and new function. "Recruitment" (2020 definition) is when two traits merge and gain a new function in the process, or enhanced one of the original functions.

2 months ago (edited) | [YT] | 56