Department of Ecology and Evolution, Stony Brook University, Stony Brook, New York, USA.
Cornell Lab of Ornithology, Cornell University, Ithaca, New York, USA.
Mol Ecol. 2024 Mar;33(6):e17282. doi: 10.1111/mec.17282. Epub 2024 Feb 1.
Many species are shifting their ranges in response to climate-driven environmental changes, particularly in high-latitude regions. However, the patterns of dispersal and colonization during range shifting events are not always clear. Understanding how populations are connected through space and time can reveal how species navigate a changing environment. Here, we present a fine-scale population genomics study of gentoo penguins (Pygoscelis papua), a presumed site-faithful colonial nesting species that has increased in population size and expanded its range south along the Western Antarctic Peninsula. Using whole genome sequencing, we analysed 129 gentoo penguin individuals across 12 colonies located at or near the southern range edge. Through a detailed examination of fine-scale population structure, admixture, and population divergence, we inferred that gentoo penguins historically dispersed rapidly in a stepping-stone pattern from the South Shetland Islands leading to the colonization of Anvers Island, and then the adjacent mainland Western Antarctica Peninsula. Recent southward expansion along the Western Antarctic Peninsula also followed a stepping-stone dispersal pattern coupled with limited post-divergence gene flow from colonies on Anvers Island. Genetic diversity appeared to be maintained across colonies during the historical dispersal process, and range-edge populations are still growing. This suggests large numbers of migrants may provide a buffer against founder effects at the beginning of colonization events to maintain genetic diversity similar to that of the source populations before migration ceases post-divergence. These results coupled with a continued increase in effective population size since approximately 500-800 years ago distinguish gentoo penguins as a robust species that is highly adaptable and resilient to changing climate.
许多物种正在响应气候驱动的环境变化而改变其分布范围，尤其是在高纬度地区。然而，在分布范围变化事件中，扩散和殖民的模式并不总是清楚的。了解种群如何通过空间和时间连接，可以揭示物种如何在不断变化的环境中导航。在这里，我们提出了一个关于巴布亚企鹅（Pygoscelis papua）的精细种群基因组学研究，巴布亚企鹅是一种假定的定点繁殖的殖民地筑巢物种，其种群数量增加，并沿着西南极半岛向南扩展其范围。使用全基因组测序，我们分析了 129 只巴布亚企鹅个体，这些个体分布在 12 个位于或接近南部范围边缘的殖民地中。通过对精细种群结构、混合和种群分歧的详细考察，我们推断巴布亚企鹅历史上以石墙式的扩散模式迅速从南设得兰群岛扩散，导致安沃尔岛的殖民化，然后是相邻的西南极半岛大陆。最近，西南极半岛的向南扩展也遵循石墙式扩散模式，同时来自安沃尔岛的殖民地的基因流有限。遗传多样性似乎在历史扩散过程中在各个殖民地得到维持，而范围边缘的种群仍在增长。这表明大量的移徙者可能在殖民事件开始时为建立者效应提供缓冲，以维持与迁移停止后的源种群相似的遗传多样性。这些结果加上自大约 500-800 年前以来有效种群数量的持续增加，将巴布亚企鹅区分出来，成为一种适应力强、对气候变化具有弹性的稳健物种。
