An experimental test of alternative population augmentation scenarios
An experimental test of alternative population augmentation scenarios
复制标题
替代人口增加情景的实验测试
DOI：
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发表时间：
2018
影响因子：
6.3
通讯作者：
W. C. Funk
中科院分区：
文献类型：
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作者：
J. Kronenberger;Jill C. Gerberich;S. Fitzpatrick;E. D. Broder;L. Angeloni;W. C. Funk
人类的土地使用正在使世界各地的生境支离破碎，并阻碍了以前相互联系的生物种群之间的扩散，在环境迅速变化的情况下，往往导致近亲繁殖减少和进化潜力降低。为了对抗这种孤立的人口与移民的增加，有时被用来促进人口和遗传拯救。与目标群体在遗传和适应性上相似的移民的扩增有效地增加了群体适应性，但如果移民在遗传或适应性上非常不同，扩增可能导致远系繁殖衰退。尽管移民来源的最佳实践选择的指导方针被广泛引用，但通常只有高度分化的人群仍然存在，并且这些风险较高的扩增场景的实验测试基本上不存在。我们进行了一个围隔实验与特立尼达孔雀鱼（孔雀鱼），以测试多代人口和遗传效应的3种不同的移民增加2个目标群体。我们没有发现人口拯救的证据，但我们确实在一个人群中观察到了基因拯救。不同的移民治疗往往保持更大的遗传多样性，丰度，和混合健身比控制接收移民的来源用于种子的围隔。在第二个种群中，不同的移民在一个处理中有轻微的负面影响，而扩增的好处总体上不太明显，可能是因为这个种群开始时具有较高的遗传多样性和较低的生殖率，限制了遗传混合。我们的研究结果增加了一个越来越多的共识，即基因流可以增加人口的健身，即使移民是更高的分歧，并可能有助于减少不确定性的保护使用增强。
Human land use is fragmenting habitats worldwide and inhibiting dispersal among previously connected populations of organisms, often leading to inbreeding depression and reduced evolutionary potential in the face of rapid environmental change. To combat this augmentation of isolated populations with immigrants is sometimes used to facilitate demographic and genetic rescue. Augmentation with immigrants that are genetically and adaptively similar to the target population effectively increases population fitness, but if immigrants are very genetically or adaptively divergent, augmentation can lead to outbreeding depression. Despite well‐cited guidelines for the best practice selection of immigrant sources, often only highly divergent populations remain, and experimental tests of these riskier augmentation scenarios are essentially nonexistent. We conducted a mesocosm experiment with Trinidadian guppies (Poecilia reticulata) to test the multigenerational demographic and genetic effects of augmenting 2 target populations with 3 types of divergent immigrants. We found no evidence of demographic rescue, but we did observe genetic rescue in one population. Divergent immigrant treatments tended to maintain greater genetic diversity, abundance, and hybrid fitness than controls that received immigrants from the source used to seed the mesocosms. In the second population, divergent immigrants had a slightly negative effect in one treatment, and the benefits of augmentation were less apparent overall, likely because this population started with higher genetic diversity and a lower reproductive rate that limited genetic admixture. Our results add to a growing consensus that gene flow can increase population fitness even when immigrants are more highly divergent and may help reduce uncertainty about the use of augmentation in conservation.