Limited genetic differentiation among chinstrap penguin (Pygoscelis antarctica) colonies in the Scotia Arc and Western Antarctic Peninsula
Limited genetic differentiation among chinstrap penguin (Pygoscelis antarctica) colonies in the Scotia Arc and Western Antarctic Peninsula
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DOI：
10.1007/s00300-015-1711-2
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发表时间：
2015-09-01
期刊：
影响因子：
1.7
通讯作者：
Hart, Tom
中科院分区：
文献类型：
--
作者：
Freer, Jennifer J.;Mable, Barbara K.;Hart, Tom
对南极洲周围海鸟数量的长期监测显示，金丝雀企鹅(南极洲金丝雀)在整个Scotia Arc活动范围内都在大幅下降。这一大片地区的群岛是通过扩散保持联系，还是代表基因上孤立的群体，目前还没有确定。本研究的目的是利用基于微卫星的种群结构分析方法，评估西南极半岛(WAP)、南设得兰、南奥克尼和南桑威奇群岛四个繁殖群体之间的遗传分化水平。所有群体具有相似的遗传多样性水平(平均杂合度，H(O)=0.583)，但来自华南和南奥克尼岛的群体具有显著的近交系数。分层和成对的F统计数据显示，斯科舍弧区的人口结构非常有限，来自WAP、南设得兰和南奥克尼群岛的殖民地相对于南桑威奇群岛的分化较弱，南桑威奇群岛与这些其他群岛至少相距1000公里。基于贝叶斯模型的聚类法没有发现显著的种群结构的证据，这表明虽然可能会发生一些距离隔离，但在这个广泛的地理范围内扩散没有强大的障碍。没有发现性别歧视扩散的证据。我们的结论是，横跨Scotia Arc的chinstrap企鹅群代表着一个相互关联的繁殖种群。高水平的基因流动对于维持较小的、不太稳定的群体可能是重要的，这种状态应该通过在整个Scotia Arc建立扩散走廊来保持。
Long-term monitoring of seabird numbers around Antarctica has revealed that the chinstrap penguin (Pygoscelis antarctica) is largely declining throughout its range in the Scotia Arc. Whether archipelagos across this large area remain connected via dispersal or represent genetically isolated groups has not yet been established. The purpose of this study was to assess the level of genetic differentiation between four breeding colonies on the Western Antarctic Peninsula (WAP), South Shetland, South Orkney, and South Sandwich Islands using microsatellite-based analysis of population structure. All colonies had similar levels of genetic diversity (mean heterozygosity, H (O) = 0.583) but colonies from the WAP and South Orkney Island had significant inbreeding coefficients. Hierarchical and pairwise F-statistics revealed very limited population structure in the Scotia Arc, with weak differentiation between colonies from the WAP, South Shetland and South Orkney Islands relative to the South Sandwich Islands, which are situated at least 1000 km apart from these other archipelagos. Bayesian model-based clustering methods found no evidence of significant population structuring, suggesting that whilst some isolation by distance may occur, there are no strong barriers to dispersal across this wide geographic range. No evidence of sex-biased dispersal was detected. We conclude that chinstrap penguin colonies across the Scotia Arc represent one interconnected breeding population. High levels of gene flow may be important in maintaining smaller, less stable colonies, and this status should be preserved by creating dispersal corridors throughout the Scotia Arc.