Contribution of inbreeding to extinction risk in threatened species
Contribution of inbreeding to extinction risk in threatened species
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DOI：
10.5751/es-00387-060116
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发表时间：
2002-06
期刊：
影响因子：
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通讯作者：
B. Brook;D. Tonkyn;Julian J. O'Grady;R. Frankham
中科院分区：
文献类型：
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作者：
B. Brook;D. Tonkyn;Julian J. O'Grady;R. Frankham
野生种群面临着来自确定性因素的威胁，例如，栖息地丧失、过度开发、污染和引进物种，以及人口、遗传和环境性质的随机事件，包括灾难。近亲繁殖降低了自然远交物种的生殖适合度，但它在野生种群的繁殖中的作用是有争议的。为了严格评估近亲繁殖在灭绝中的作用，我们对20种受威胁的物种进行了现实的种群生存能力分析，有和没有近亲繁殖衰退，使用初始种群规模为50，250和1000。近亲繁殖显着减少中位数时间灭绝的50，250，和1000，分别为初始种群的28.5%，30.5%和25%，在主要类群的影响是相似的。解释物种间差异的主要变量是初始种群增长率，而在负增长率的物种中，近亲繁殖的影响最小。这些结果表明，受威胁物种的生存前景通常会被严重高估，如果遗传因素被忽视，如果近亲繁殖衰退被忽视，可能会制定不适当的恢复计划。
Wild populations face threats both from deterministic factors, e.g., habitat loss, overexploitation, pollution, and introduced species, and from stochastic events of a demographic, genetic, and environmental nature, including catastrophes. Inbreeding reduces reproductive fitness in naturally outbreeding species, but its role in extinctions of wild populations is controversial. To evaluate critically the role of inbreeding in extinction, we conducted realistic population viability analyses of 20 threatened species, with and without inbreeding depression, using initial population sizes of 50, 250, and 1000. Inbreeding markedly decreased median times to extinction by 28.5, 30.5, and 25% for initial populations of 50, 250, and 1000, respectively, and the impacts were similar across major taxa. The major variable explaining differences among species was initial population growth rate, whereas the impact of inbreeding was least in species with negative growth rates. These results demonstrate that the prospects for survival of threatened species will usually be seriously overestimated if genetic factors are disregarded, and that inappropriate recovery plans may be instituted if inbreeding depression is ignored.