Fitness is the ability to fulfill a particular role or task. In evolutionary biology, fitness is an individual's ability to propagate its genes, i.e. the ability to leave offspring in its particular environment. It is a measure how good an organism or species is adapted to its environment. Charles Darwin used the verb "fit" synonymously with "adapt", and the adjective "fitted" with "adapted" or "suitable" (Keller and Lloyd, 1992). Fitness in general describes the ability to both survive and reproduce, and can be mesaure in evolutionary systems as survival period or offspring production in a particular environment.
- Wikipedia Entry for http://en.wikipedia.org/wiki/Fitness_(biology)
- Evelyn Fox Keller and Elisabeth A. Lloyd, "Keywords in Evolutionary Biology", Harvard University Press, 1992