Climatic changes can affect species distributions, population abundance, and evolution. Such organismal responses could be determined by the amount and quality of available habitats, which can vary independently. In this study, we assessed changes in habitat quantity and quality independently to generate explicit predictions of the species' responses to climatic changes between Last Glacial Maximum (LGM) and present day. We built ecological niche models for genetic groups within 21 reptile, mammal, and plant taxa from the Baja California peninsula inhabiting lowland or highland environments. Significant niche divergence was detected for all clades within species, along with significant differences in the niche breadth and area of distribution between northern and southern clades. We quantified habitat quantity from the distribution models, and most clades showed a reduction in distribution area towards LGM. Further, niche marginality (used as a measure of habitat quality) was higher during LGM for most clades, except for northern highland species. Our results suggest that changes in habitat quantity and quality can affect organismal responses independently. This allows the prediction of genomic signatures associated with changes in effective population size and selection pressure that could be explicitly tested from our models.

中文翻译：

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栖息地质量还是数量？ 21 种植物和动物的生态位边缘表明高地和低地物种对过去气候变化的反应不同


气候变化会影响物种分布、种群丰度和进化。这种生物反应可能由可用栖息地的数量和质量决定，而这些栖息地可以独立变化。在这项研究中，我们独立评估了栖息地数量和质量的变化，以生成物种对末次盛冰期（LGM）至今气候变化的反应的明确预测。我们为来自下加利福尼亚半岛低地或高地环境的 21 种爬行动物、哺乳动物和植物类群的遗传群体建立了生态位模型。物种内所有分支均检测到显着的生态位差异，并且北部和南部分支之间的生态位宽度和分布面积存在显着差异。我们根据分布模型对栖息地数量进行了量化，大多数进化枝的分布面积都出现了 LGM 的减少。此外，除北部高地物种外，大多数进化枝在末次盛冰期期间的生态位边际性（用作栖息地质量的衡量标准）较高。我们的结果表明，栖息地数量和质量的变化可以独立影响生物体的反应。这使得可以预测与有效种群规模和选择压力变化相关的基因组特征，这些变化可以从我们的模型中明确测试。