TABLE 1

Frequently used notations

SymbolUsage
CAverage improvement in log-fitness per generation.
ΔCAverage improvement in log-fitness per beneficial substitution.
fiFraction of the wild-type population carrying i deleterious alleles.
hiNumber of deleterious alleles fixed by hitchhiking, conditional on the beneficial allele arising in background i and becoming fixed.
iNumber of deleterious alleles in a given genetic background.
imaxGreatest i for which Pi ≠ 0.
IInflation of fixation probability caused by nonequilibrium wild-type population.
kRatio of beneficial to deleterious mutations.
mi,jProbability that offspring is in site j given parent in site i.
NPopulation size.
p[∙]Unique function satisfying 0 ≤ p[s] ≡ 1 - exp[-(1 + s)p[s]].
piAbbreviation for p[e-U Wi - 1].
PfixFixation probability of a single copy of the beneficial allele arising in a random genetic background.
PiFixation probability of a single copy of the beneficial allele in background i.
QiExtinction probability; 1 - Pi.
RRelative fixation probability (relative to no interference).
sbSelection coefficient for the beneficial allele under consideration.
sdSelection coefficient against a deleterious allele.
UDeleterious mutation rate per individual per generation.
wFitness relative to fittest wild-type genotype present.
WAbsolute fitness, i.e., expected number of offspring.
xiContribution to Pi arising from beneficial alleles lost from their original background but fixed in some lower fitness background.
λMean i in the wild-type population.