School of Biological Sciences, University of East Anglia Norwich, Norfolk, UK ; Behavioural Ecology and Self-organization Group, Centre for Ecological and Evolutionary Studies, University of Groningen Groningen, The Netherlands.
School of Biological Sciences, University of East Anglia Norwich, Norfolk, UK ; Department of Animal and Plant Sciences, NERC Biomolecular Analysis Facility, University of Sheffield Sheffield, UK.
Evol Appl. 2014 Nov;7(9):1134-43. doi: 10.1111/eva.12191. Epub 2014 Aug 11.
The importance of evolutionary conservation - how understanding evolutionary forces can help guide conservation decisions - is widely recognized. However, the historical demography of many endangered species is unknown, despite the fact that this can have important implications for contemporary ecological processes and for extinction risk. Here, we reconstruct the population history of the Seychelles warbler (Acrocephalus sechellensis) - an ecological model species. By the 1960s, this species was on the brink of extinction, but its previous history is unknown. We used DNA samples from contemporary and museum specimens spanning 140 years to reconstruct bottleneck history. We found a 25% reduction in genetic diversity between museum and contemporary populations, and strong genetic structure. Simulations indicate that the Seychelles warbler was bottlenecked from a large population, with an ancestral N e of several thousands falling to <50 within the last century. Such a rapid decline, due to anthropogenic factors, has important implications for extinction risk in the Seychelles warbler, and our results will inform conservation practices. Reconstructing the population history of this species also allows us to better understand patterns of genetic diversity, inbreeding and promiscuity in the contemporary populations. Our approaches can be applied across species to test ecological hypotheses and inform conservation.
进化保护的重要性——了解进化力量如何帮助指导保护决策——已得到广泛认可。然而，许多濒危物种的历史种群动态却未知，尽管这对当代生态过程和灭绝风险有重要影响。在这里，我们重建了塞舌尔莺（Acrocephalus sechellensis）——一种生态模式物种的种群历史。到 20 世纪 60 年代，这种物种已濒临灭绝，但它的过去历史却未知。我们利用跨越 140 年的当代和博物馆标本的 DNA 样本来重建瓶颈历史。我们发现，博物馆和当代种群之间的遗传多样性减少了 25%，并且存在强烈的遗传结构。模拟表明，塞舌尔莺是从一个大种群中经历瓶颈效应的，其祖先的有效种群数量（Ne）约为数千，在过去一个世纪中降至<50。由于人为因素导致如此迅速的下降，对塞舌尔莺的灭绝风险有重要影响，我们的结果将为保护实践提供信息。重建该物种的种群历史也使我们能够更好地理解当代种群中遗传多样性、近交和杂交的模式。我们的方法可以应用于各个物种，以检验生态假设并为保护提供信息。
