Fitness Components

Darwinian Fitness is often equated with simple survival (as in the unfortunate phrase "Survival of the FIttest"). However, Darwin himself emphasize that fitness encompassed both survival and reproduction. Aspects of life history that affect success in reproduction include Sexual Selection (morphological or behavioral attributes that affects success in attracting mates), Fecundity selection (for example, r and K strategies of offspring numbers), Gametic selection (biochemical competition among sperm for access to the egg), and Compatibility selection (differential fertilization success amongst sperm and egg genomes with different genotypes). Any or all of these components can be measured.