Research Scholars Annex Hall

Effect of drift, selection and recombination on the equilibrium frequency of deleterious mutations

Sona John

JNCASR, Bangalore

We study the advantage of recombination for a population evolving under the action of random genetic
drift, selection and both deleterious and reverse beneficial mutations. We find that the equilibrium fraction
of deleterious mutations decreases (or fitness increases) as the population size increased for both sexual
and asexual populations. Whereas recombination alleviates the effect of deleterious mutations for
moderately large populations, but for small and very large populations, the fraction of deleterious
mutations depends weakly on recombination. An analytical argument shows recombination decreases the
fraction of deleterious mutations appreciably when beneficial mutations are rare as in the case of
adapting populations, whereas it has a moderate effect on codon bias where the mutation rates between
the prefferred and unpreffered codons are comparable. All these results obtained by considering a smooth
single peak fitness landscape, but now we are trying to explore the advantage of recombination in a more
realistic tunable rugged landscape.