RT Journal Article
SR Electronic
T1 Mutation-Selection Balance, Dominance and the Maintenance of Sex
JF Genetics
JO Genetics
FD Genetics Society of America
SP 1419
OP 1425
VO 156
IS 3
A1 Chasnov, J. R.
YR 2000
UL http://www.genetics.org/content/156/3/1419.abstract
AB A leading hypothesis for the evolutionary function of sex postulates that sex is an adaptation that purges deleterious mutations from the genome, thereby increasing the equilibrium mean fitness of a sexual population relative to its asexual competitor. This hypothesis requires two necessary conditions: first, the mutation rate per genome must be of order one, and, second, multiple mutations within a genome must act with positive epistasis, that is, two or more mutations of different genes must be more harmful together than if they acted independently. Here, by reconsidering the theory of mutation-selection balance at a single diploid gene locus, we demonstrate a significant advantage of sex due to nearly recessive mutations provided the mutation rate per genome is of order one. The assumption of positive epistasis is unnecessary, and multiple mutations may be assumed to act independently.