Fitness

Definition

A measure of an organism's ability to survive and reproduce in its environment.

Etymology

From English 'fit', influenced by Old English 'fitt', meaning 'a conflict or contest'.

Example

The fitness of a butterfly depends on its ability to find food, avoid predators, and successfully reproduce.

Related Terms

• Adaptation
• Selection

Usage Notes

In entomology, fitness is often used to refer to the relative success of different genotypes in passing on their genes to the next generation.