The conditional ancestral selection graph with strong balancing selection.
Using a heuristic separation-of-time-scales argument, we describe the behavior of the conditional ancestral selection graph with very strong balancing selection between a pair of alleles. In the limit as the strength of selection tends to infinity, we find that the ancestral process converges to a neutral structured coalescent, with two subpopulations representing the two alleles and mutation playing the role of migration. This agrees with a previous result of Kaplan et al., obtained using a different approach. We present the results of computer simulations to support our heuristic mathematical results. We also present a more rigorous demonstration that the neutral conditional ancestral process converges to the Kingman coalescent in the limit as the mutation rate tends to infinity.
Wakeley
John
J
Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA. wakeley@fas.harvard.edu
Sargsyan
Ori
O
D000483:Alleles; D003198:Computer Simulation; D008962:Models, Theoretical; D012641:Selection, Genetic