반수체 모형에서 돌연변이에 의한 성비의 치우침

Abstract

A question in evolutionary biology is why the number of males is approximately equal to that of females in many species, and Fisher’s theory of equal investment answers that it is the evolutionarily stable state. The Fhisherian mechanism can be given a concrete form by a genetic model based on the following assumptions: (1) Males and females mate at random. (2): An allele acts on the father to determine the progeny sex ratios. In this study, however, we argue that mutation plays a more subtle role in that fluctuations caused by mutation renormalize the sex ratio and thereby keep it away from 1:1 in general. This finding shows how the sex ratio is affected by mutation in a systemetic way, whereby the effective mutation rate can be estimated from an observed sex ratio.