Environmental changes since the Pleistocene and commercial whaling in the last few centuries have drastically reduced many whale populations, including gray whales in the North Pacific. Herein we use complete mitogenome sequences from 74 individuals to evaluate gray whale phylogeography and historical demography, then use environmental niche modeling to assess how habitat availability has changed through time for Pacific gray whales. We identify a large degree of haplotype sharing between gray whales sampled in Russian and Mexican waters, coupled with very limited matrilineal population structure. Confirming previous studies, our environmental niche models showed a decrease in available habitat during the Last Glacial Maximum, but we find no genetic signals of recent population declines in mitochondrial genomes despite both sustained habitat loss and a commercial whaling bottleneck. Our results illustrate the complex dynamics of baleen whale biogeography since the Holocene as well as the difficulty in detecting recent demographic bottlenecks from mitochondrial DNA sequences.

中文翻译：

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从全线粒体基因组序列和环境生态位模型推断，全新世栖息地可用性对太平洋灰鲸 (Eschrichtius robustus) 种群动态的影响

自更新世以来的环境变化和过去几个世纪的商业捕鲸活动已经大大减少了许多鲸鱼的数量，包括北太平洋的灰鲸。在这里，我们使用来自 74 个人的完整有丝分裂基因组序列来评估灰鲸的系统地理学和历史人口学，然后使用环境生态位模型来评估太平洋灰鲸的栖息地可用性如何随时间变化。我们发现在俄罗斯和墨西哥水域采样的灰鲸之间存在很大程度的单倍型共享，以及非常有限的母系种群结构。确认先前的研究，我们的环境生态位模型显示在末次盛冰期可用栖息地减少，但我们没有发现线粒体基因组近期种群减少的遗传信号，尽管栖息地持续丧失和商业捕鲸瓶颈。我们的研究结果说明了自全新世以来须鲸生物地理学的复杂动态，以及从线粒体 DNA 序列中检测近期人口统计学瓶颈的困难。