Bats are atypical small mammals. Size is crucial for bats because it affects most aerodynamic variables and several key echolocation parameters. In turn, scaling relationships of both flight and echolocation have been suggested to constrain bat body size evolution. Previous studies have found a large phylogenetic effect and the inclusion of early Eocene fossil bats contributed to recover idiosyncratic body size change patterns in bats. Here, we test these previous hypotheses of bat body size evolution using a large, comprehensive supermatrix phylogeny (+800 taxa) to optimize body size and examine changes reconstructed along branches. Our analysis provides evidence of rapid stem phyletic nanism, an ancestral value stabilized at 12 g for crown-clade Chiroptera followed by backbone stasis, low-magnitude changes inside established families, and massive body size increase at accelerated rate in pteropodid subclades. Total variation amount explained by pteropodid subclades was 86.3%, with most changes reconstructed as phyletic increases but also apomorphic decreases. We evaluate these macroevolutionary patterns in light of the constraints hypothesis, and in terms of both neutral and adaptive evolutionary models. The reconstructed macroevolution of bat body size led us to propose that echolocation and flight work as successive, nested constraints limiting bat evolution along the body size scale.

中文翻译：

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蝙蝠体重的进化：来自大型超级矩阵系统发育的见解

蝙蝠是非典型的小型哺乳动物。尺寸对蝙蝠至关重要，因为它会影响大多数空气动力学变量和几个关键的回声定位参数。反过来，飞行和回声定位的比例关系已被建议限制蝙蝠体型的进化。以前的研究发现了一个很大的系统发育效应，早期始新世蝙蝠化石的加入有助于恢复蝙蝠的特殊体型变化模式。在这里，我们使用大型综合超矩阵系统发育（+800 个分类群）来测试蝙蝠体型进化的这些先前假设，以优化体型并检查沿分支重建的变化。我们的分析提供了快速茎系统进化的证据，冠枝手足目的祖先值稳定在 12 g，随后是骨干停滞，已建立家庭内部的低幅度变化，和巨大的体型在翼足类亚支中以加速的速度增加。翼足类亚分支解释的总变异量为 86.3%，大多数变化随着系统的增加而重建，但也有变质减少。我们根据约束假设以及中性和适应性进化模型评估这些宏观进化模式。蝙蝠体型的重构宏观进化使我们提出回声定位和飞行作为连续的、嵌套的约束限制蝙蝠沿体型的进化。我们根据约束假设以及中性和适应性进化模型评估这些宏观进化模式。蝙蝠体型的重构宏观进化使我们提出回声定位和飞行作为连续的、嵌套的约束限制蝙蝠沿体型的进化。我们根据约束假设以及中性和适应性进化模型评估这些宏观进化模式。蝙蝠体型的重构宏观进化使我们提出回声定位和飞行作为连续的、嵌套的约束限制蝙蝠沿体型的进化。