natural selection
The process by which individuals’ inherited needs and abilities are more or less closely matched to resources available in their environment, giving those with greater "fitness" a better chance of survival and reproduction.
Charles Darwin’s theory of biological evolution, based on the survival and replication of the fittest and most adaptable genes, through competition over limited natural resources.
References
Jensen JD, Wong A, Aquadro CF. Approaches for identifying targets of positive selection. Trends Genet. 2007 Nov;23(11):568-77. PMID: 17959267
Gilad Y, Oshlack A, Rifkin SA. Natural selection on gene expression. Trends Genet. 2006 Aug;22(8):456-61. PMID: 16806568
Vallender EJ, Lahn BT. Positive selection on the human genome. Hum Mol Genet. 2004 Oct 1;13 Spec No 2:R245-54. PMID: 15358731
Wooding S. Natural selection: sign, sign, everywhere a sign. Curr Biol. 2004 Sep 7;14(17):R700-1. PMID: 15341758