The effect of variable progeny size and social selection on the population dynamics of rare lethal genes

Abstract

When a family has a member affected by a rare lethal genetic disease, the normal members of the family have a reduced chance of marrying or of reaching the fertility level of the general population. This paper shows that gene frequency change is divided approximately into two parts: the change due to individual selection and that due to social pressure. It is also shown that a large progeny size in a family generally decreases the equilibrium of lethal genes because of social pressure.