Handicaps are costly traits in organisms, often in animals.

One way of explaining them is as a form of signalling. Cf. Biosemiotics, Biocommunicaiton

Zahavi, Amotz, and Avishag Zahavi. The Handicap Principle: A Missing Piece of Darwin’s Puzzle. Revised. New York: Oxford University Press, 1997.

Biernaskie, Jay M., Jennifer C. Perry, and Alan Grafen. ‘A General Model of Biological Signals, from Cues to Handicaps’. Evolution Letters 2, no. 3 (2018): 201–9. https://doi.org/10/grwz7s.

Relevant for design, bioinspiration, biomimicry as a pattern that is hard to separate from the rest of phenotypical traits but that is also easy to see as not useful out of context. Cf. Biomimicry