Premium
EPISTASIS AS A SOURCE OF INCREASED ADDITIVE GENETIC VARIANCE AT POPULATION BOTTLENECKS
Author(s) -
Cheverud James M.,
Routman Eric J.
Publication year - 1996
Publication title -
evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.84
H-Index - 199
eISSN - 1558-5646
pISSN - 0014-3820
DOI - 10.1111/j.1558-5646.1996.tb02345.x
Subject(s) - epistasis , biology , population , genetic variation , population bottleneck , evolutionary biology , genetic architecture , dominance (genetics) , genetics , allele , quantitative trait locus , gene , demography , sociology , microsatellite
The role of epistasis in evolution and speciation has remained controversial. We use a new parameterization of physiological epistasis to examine the effects of epistasis on levels of additive genetic variance during a population bottleneck. We found that all forms of epistasis increase average additive genetic variance in finite populations derived from initial populations with intermediate allele frequencies. Average additive variance continues to increase over many generations, especially at larger population sizes ( N = 32 to 64). Additive‐by‐additive epistasis is the most potent source of additive genetic variance in this situation, whereas dominance‐by‐dominance epistasis contributes smaller amounts of additive genetic variance. With additive‐by‐dominance epistasis, additive genetic variance decreases at a relatively high rate immediately after a population bottleneck, rebounding to higher levels after several generations. Empirical examples of epistasis for murine adult body weight based on measured genotypes are provided illustrating the varying effects of epistasis on additive genetic variance during population bottlenecks.