Thompson E A, Roberts D F
Am J Hum Genet. 1980 May;32(3):445-52.
Although there are many factors influencing the genotype proportions in a small population [1], a heterozygote excess, caused by avoidance of incestuous matings, will often be the expected observation. In the population of the small South-Atlantic islands of Tristan da Cunha, such an excess if observed [2], and we have investigated its origin, partitioning the population by sex and by generation. Although for such a small population the test for random pairing of genes [3, 4] is not sufficiently powerful to produce significant results, the pattern of homozygote deficiency is suggestive of avoidance of close matings. We have also investigated the effect of current nuclear family structure and family-size distribution.
尽管有许多因素会影响小群体中的基因型比例[1]，但由于避免近亲交配导致的杂合子过剩往往是预期的观察结果。在南大西洋特里斯坦-达库尼亚群岛的小群体中，如果观察到这种过剩现象[2]，我们就会按性别和世代对群体进行划分，研究其起源。尽管对于这样一个小群体来说，基因随机配对的检验[3,4]不够有力，无法产生显著结果，但纯合子不足的模式表明存在避免近亲交配的情况。我们还研究了当前核心家庭结构和家庭规模分布的影响。
