小种群的遗传变异和近交衰退

小种群一般拥有较小的遗传变异.当前人为干扰和破坏造成了生物种群个体数量减少,导致种群遗传多样性丧失,引起近交衰退,影响到种群后代适应性.产生近交衰退的原因是近交增加了有害等位基因纯合几率,导致个体适应能力下降.近交衰退受交配系统、世系效应、环境胁迫等的影响.在物种保护和恢复过程中,要防止近交衰退.

Genetic Variation and Inbreeding Depression in Small Populations

Inbreeding depression has long been observed because it exists in ourselves due to consanguineous mating. Inbreeding may reduce population fitness through the expression of recessive, deleterious alleles in homozygous form. Inbreeding depression is influenced by lineage effects, mating system, environment stress and so on. Human disturbance and overexploitation are the main reasons causing population decline and consequently inbreeding depression. For species conservation and restoration, we should take inbreeding into consideration.