RATE OF DECREASE OF GENETIC VARIABILITY IN A TWO-DIMENSIONAL CONTINUOUS POPULATION OF FINITE SIZE

[摘要] The rate of decay of genetic variability was investigated for two-dimensional continuous populations of finite size. The exact value of the rate involves a rather complicated expression (formula (4-1)). However, numerical examples indicate that in a population habitat size L × L and density D , the rate is approximately equal to (see PDF) where σ2 is the variance of dispersion distance assuming isotropical migration. The value given in (2) is equal to that of a panmictic population of size DL 2. It is remarkable that whether the rate assumes the value given by (1) or by (2) depends only on D σ2 (a local property), which is independent of the habitat size. Since, in a one-dimensional population, this depends on both D σ2 and the habitat size, there is an essential difference between the two types of population structure.—The function giving the probability of two homologous genes separated by a given distance being different alleles was also obtained, (formula (5-1)).

[学科分类] 医学（综合）