Coalescent theory for age-structured random mating populations with two sexes

► Theory is derived for age-structured random mating populations with two sexes. ► Time points, backward from the present, are assumed to be discrete and equally spaced. ► Unchanging numbers in various age-sex classes are assumed. ► Coalescent theory then holds under fairly general conditions. ► Time in this process is measured in multiples of twice the effective population size.