Department of Forestry & Natural Resources, Purdue University, West Lafayette, IN, USA.
Camp Fire Program in Wildlife Conservation, State University of New York College of Environmental Science and Forestry, Syracuse, NY, USA.
Mol Ecol. 2019 Nov;28(22):4914-4925. doi: 10.1111/mec.15266. Epub 2019 Oct 26.
Genomic diversity is the evolutionary foundation for adaptation to environmental change and thus is essential to consider in conservation planning. Island species are ideal for investigating the evolutionary drivers of genomic diversity, in part because of the potential for biological replicates. Here, we use genome data from 180 individuals spread among 27 island populations from 17 avian species to study the effects of island area, body size, demographic history and conservation status on contemporary genomic diversity. Our study expands earlier work on a small number of neutral loci to the entire genome and from a few species to many. We find significant positive correlation between island size and genomic diversity, a significant negative correlation between body size and genomic diversity, and that historical population declines significantly reduced contemporary genomic diversity. Our study shows that island size is the key factor in determining genomic diversity, indicating that habitat conservation is key to maintaining adaptive potential in the face of global environmental change. We found that threatened species generally had a significantly smaller values of Watterson's theta (θ = 4N μ) compared to nonthreatened species, suggesting that θ may be useful as a conservation indicator for at-risk species. Overall, these findings (a) provide biological insights into how genomic diversity scales with ecological, morphological and demographic factors; and (b) illustrate how population genomic data can be leveraged to better inform conservation efforts.
基因组多样性是适应环境变化的进化基础，因此在保护规划中必须加以考虑。岛屿物种是研究基因组多样性进化驱动因素的理想选择，部分原因是它们具有潜在的生物学重复。在这里，我们使用来自 17 种鸟类的 180 个个体的基因组数据，这些个体分布在 27 个岛屿种群中，研究了岛屿面积、体型、种群历史和保护状况对当代基因组多样性的影响。我们的研究将早期在少数中性基因座上的工作扩展到整个基因组，并从少数物种扩展到许多物种。我们发现岛屿大小与基因组多样性呈显著正相关，体型与基因组多样性呈显著负相关，历史种群下降显著降低了当代基因组多样性。我们的研究表明，岛屿大小是决定基因组多样性的关键因素，这表明栖息地保护是在全球环境变化面前保持适应潜力的关键。我们发现，受威胁物种的 Watterson 氏θ（θ=4Nμ）值通常明显小于非受威胁物种，这表明θ值可用作濒危物种的保护指标。总的来说，这些发现（a）提供了关于基因组多样性如何与生态、形态和人口因素相关的生物学见解；（b）说明了如何利用群体基因组数据更好地为保护工作提供信息。
