- Evolutionary theory focuses on the idea of Darwin's natural selection.
- The survival of the fittest is the idea of reproductive fitness.
- Evolutionary psychology assumes that individuals act in particular ways to increase the survival of their genes.
Sperm competition - natural selection caused males to be more competitive by producing larger testicles, more copious ejaculations and faster swimming sperm. This is supported by Simmons research which found that testes size was larger in humans than of other monogamous animal species therefore supporting the theory of competition and natural selection.
Size - males evolved to be bigger demonstrating strength and threat to other males in competition for a mate. This is more obvious in some species such as deer evolving antlers.
- Clark and Hatfield found that males are more promiscuous therefore supporting gender differences in sexual selection.
- Dewsbury found support for sperm competition in other species as multiple male rats mate…