Genetic evidence for widespread population size expansion in North American boreal birds prior to the Last Glacial Maximum
Genetic evidence for widespread population size expansion in North American boreal birds prior to the Last Glacial Maximum
复制标题
DOI：
10.1098/rspb.2022.1334
复制
发表时间：
2023-01-25
影响因子：
4.7
通讯作者：
Winger，Benjamin M. M.
中科院分区：
文献类型：
--
作者：
Kimmitt，Abigail A. A.;Pegan，Teresa M. M.;Winger，Benjamin M. M.
更新世的气候周期被很好地记录下来，塑造了当代的物种分布和遗传多样性。据推测，在末次盛冰期（LGM，约21 000年前）后，冰川消退导致向北的范围扩大，导致陆地类群的人口规模扩大和季节性迁徙行为的变化。然而，最近的研究结果表明，一些北方温带种群可能比预期的更稳定，通过LGM。我们从完整的线粒体基因组和物种特异性分子速率中模拟了19种共同分布的北方繁殖北美鸟类的人口统计学历史。我们使用这些人口重建来测试具有不同迁移策略的物种如何受到冰川周期的影响。我们的研究结果表明，有效的人口规模增加更新世冰川消退早于LGM，而遗传多样性保持在整个LGM，尽管地理范围的变化。我们的结论是，冰川周期之前的LGM最强烈地塑造了当代这些物种的遗传多样性。我们没有发现历史人口动态和迁移策略之间的关系，有助于越来越多的证据表明，在LGM迁移策略的重大转变是不必要的，以解释当代的迁移模式。
Pleistocene climate cycles are well documented to have shaped contemporary species distributions and genetic diversity. Northward range expansions in response to deglaciation following the Last Glacial Maximum (LGM; approximately 21 000 years ago) are surmised to have led to population size expansions in terrestrial taxa and changes in seasonal migratory behaviour. Recent findings, however, suggest that some northern temperate populations may have been more stable than expected through the LGM. We modelled the demographic history of 19 co-distributed boreal-breeding North American bird species from full mitochondrial gene sets and species-specific molecular rates. We used these demographic reconstructions to test how species with different migratory strategies were affected by glacial cycles. Our results suggest that effective population sizes increased in response to Pleistocene deglaciation earlier than the LGM, whereas genetic diversity was maintained throughout the LGM despite shifts in geographical range. We conclude that glacial cycles prior to the LGM have most strongly shaped contemporary genetic diversity in these species. We did not find a relationship between historic population dynamics and migratory strategy, contributing to growing evidence that major switches in migratory strategy during the LGM are unnecessary to explain contemporary migratory patterns.