Modeling the effect of changing selective pressures on polymorphism and divergence.

ABSTRACT: The most common models of sequence evolution used to make inferences about adaptation rely on the assumption that selective pressures at a site remain constant through time. Instead, one might plausibly imagine that a change in the environment renders an allele beneficial and that when it fixes, the site is now constrained-until another change in the environment occurs that affects the selective pressures at that site. With this view in mind, we introduce a simple dynamic model for the evolution of coding regions, in which non-synonymous sites alternate between being fixed for the favored allele and being neutral with respect to other alleles. We use the pruning algorithm to derive closed forms for observable patterns of polymorphism and divergence in terms of the model parameters. Using o

SUBMITTER: Benger E 

PROVIDER: S-EPMC4296563 | biostudies-literature | 2013 May

REPOSITORIES: biostudies-literature