Department of Science, Chatham University, Pittsburgh, Pennsylvania, United States of America.
Department of Ecology and Evolutionary Biology, Yale University, New Haven, Connecticut, United States of America.
PLoS One. 2021 Aug 18;16(8):e0255393. doi: 10.1371/journal.pone.0255393. eCollection 2021.
Identifying the historical processes that drive microhabitat transitions across deep time is of great interest to evolutionary biologists. Morphological variation can often reveal such mechanisms, but in clades with high microhabitat diversity and no concomitant morphological specialization, the factors influencing animal transitions across microhabitats are more difficult to identify. Lungless salamanders (family: Plethodontidae) have transitioned into and out of the arboreal microhabitat many times throughout their evolutionary history without substantial morphological specialization. In this study, we explore the relationship between microhabitat use and broad-scale climatic patterns across species' ranges to test the role of climate in determining the availability of the arboreal microhabitat. Using phylogenetic comparative methods, we reveal that arboreal species live in warmer, lower elevation regions than terrestrial species. We also employ ecological niche modeling as a complementary approach, quantifying species-level pairwise comparisons of niche overlap. The results of this approach demonstrate that arboreal species on average display more niche overlap with other arboreal species than with terrestrial species after accounting for non-independence of niche model pairs caused by geographic and phylogenetic distances. Our results suggest that occupation of the arboreal microhabitat by salamanders may only be possible in sufficiently warm, low elevation conditions. More broadly, this study indicates that the impact of micro-environmental conditions on temporary microhabitat use, as demonstrated by small-scale ecological studies, may scale up dramatically to shape macroevolutionary patterns.
确定驱动长时间跨度中小生境转变的历史进程是进化生物学家非常感兴趣的问题。形态变异通常可以揭示这种机制，但在具有高度小生境多样性且没有相应形态特化的进化枝中，影响动物跨小生境转变的因素更难识别。无肺蝾螈（科：有肺螈科）在其进化历史中多次进出树栖小生境，而没有实质性的形态特化。在这项研究中，我们探讨了物种分布范围内的小生境利用与广泛气候模式之间的关系，以检验气候在决定树栖小生境的可利用性方面的作用。我们使用系统发育比较方法发现，树栖物种生活在比陆生物种更温暖、海拔更低的地区。我们还采用生态位模型作为补充方法，量化物种水平上的生态位重叠对。这种方法的结果表明，在考虑到由于地理和系统发育距离而导致的生态位模型对的非独立性后，树栖物种与其他树栖物种的平均生态位重叠度大于与陆生物种的生态位重叠度。我们的研究结果表明，蝾螈对树栖小生境的占据可能仅在足够温暖、低海拔的条件下才有可能。更广泛地说，这项研究表明，小规模生态研究表明的环境条件对临时小生境利用的影响可能会大大扩展，从而塑造宏观进化模式。
