reduce the female's attractiveness. The adaptation of sperm traits, such as length, viability and velocity might be constrained by the influence of cytoplasmic DNA (e.g. mitochondrial DNA); mitochondrial DNA is inherited from the mother only and it is thought that this could represent a constraint in the evolution of sperm. See also Concealed ovulation Strategic pluralism Sociobiological theories of rape Polygamy in house mouse Human sperm competition Sperm competition in mammals References Further reading Alcock, John 1998. Animal Behavior. Sixth Edition. 429-519. Eberhard, William 1996 Female Control: Sexual Selection by Cryptic Female Choice Freeman, Scott; Herron, Jon C.; (2007). Evolutionary Analysis (4th ed.). Pearson Education, Inc. . Ryan, Christopher & Jethá, Calcilda. Sex at Dawn: The prehistoric origins of modern sexuality. New York: Harper, 2010. Shackelford, T. K. & Pound, N. 2005. Sperm Competition in Humans : Classic and Contemporary Readings . Simmons, Leigh W. 2001. Sperm competition and its evolutionary consequences in the insects. Princeton University Press, and Snook, Rhonda R. Postcopulatory reproductive strategies. Encyclopedia of Life Sciences http://www.els.net Evolutionary biology Evolutionary psychology Sexual selection Semen