Canalization and Epistasis
Epistasis has been defined in multiple different ways (e.g. Hollander 1955; Philips 1998; Brodie 2000; Wade et al. 2001; Cordell 2002; Moore and Williams 2005). Most definitions relate back to early work by Bateson (1909) and Fisher (1918) that focused on "biological epistasis" and "statistical epistasis", respectively. A biological system is said to be canalized (Waddington 1942, 1957) when it is buffered against mutations and/or environmental change. Canalization results from stabilizing selection and leads to robust genetic networks that exhibit epistasis (e.g. Gibson and Wagner 2000; de Visser et al. 2003). A new review by Proulx and Phillips (2005) discusses canalization and the evolution of genetic networks.
Bateson W. Mendel's Principles of Heredity. Cambridge University Press, Cambridge, 1909.
Brodie III ED. Why evolutionary genetics does not always add up. In: Wolf J, Brodie III B, Wade M (eds) Epistasis and the Evolutionary Process, Oxford University Press, New York, pp. 3-19, 2000.
Cordell. Epistasis: what it means, what it doesn't mean, and statistical methods to detect it in humans. Hum Mol Genet. 2002 Oct 1;11(20):2463-8. [PubMed]
de Visser et al. Perspective: Evolution and detection of genetic robustness. Evolution Int J Org Evolution. 2003 Sep;57(9):1959-72. [PubMed]
Fisher RA. The correlations between relatives on the supposition of Mendelian inheritance. Trans R Soc Edinb 52:399-433, 1918.
Gibson G, Wagner G. Canalization in evolutionary genetics: a stabilizing theory? Bioessays. 2000 Apr;22(4):372-80. [PubMed]
Hollander WF. Epistasis and hypostasis. J Hered 1955;46:222-225.
Moore and WIlliams. Traversing the conceptual divide between biological and statistical epistasis: systems biology and a more modern synthesis. BioEssays 2005 June, in press. [BioEssays]
Phillips. The language of gene interaction. Genetics. 1998 Jul;149(3):1167-71. [PubMed]
Proulx and Phillips. The opportunity for canalization and the evolution of genetic networks. Am Nat. 2005 Feb;165(2):147-62. [PubMed]
Wade et al. Alternative definitions of epistasis: dependence and interaction. Trends in Ecology and Evolution 2001;16:498-504. [pdf]
Waddington CH. Canalization of development and the inheritance of acquired characters. Nature 1942;150:563-5.
Waddington CH. The Strategy of the Genes. MacMillan, New York, 1957.