Sperm competition in humans

ABSTRACT—With the recognition, afforded by recent evo-lutionary science, that female infidelity was a recurrent feature of modern humans ’ evolutionary history has come the development of a unique area in the study of human mating: sperm competition. A formofmale–male postcopul-atory competition, sperm competition occurs when the sperm of two or more males concurrently occupy the re-productive tract ofa femaleandcompete to fertilize her ova. Malesmust compete formates, but if twoormoremales have copulated with a female within a sufficiently short period of time, sperm will compete for fertilizations. Psychological, behavioral, physiological, and anatomical evidence indi-cates that men have evolved solutions to combat the adap-tive problem of sperm competition, but research has only just begun to uncover these adaptations