When comparative neuromorphological studies are extended into evolutionary contexts, traits of interest are often linked to diversification patterns. Features demonstrably associated with increases in diversification rates and the infiltration or occupation of novel niche spaces are often termed "key innovations." Within the past decade, phylogenetically informed methods have been developed to test key innovation hypotheses and evaluate the influence these traits have had in shaping modern faunas. This is primarily accomplished by estimating state-dependent speciation and extinction rates. These methods have important caveats and guidelines related to both calculation and interpretation, which are necessary to understand in cases of discrete (qualitative) character analysis, as can be common when studying the evolution of neuromorphology. In such studies, inclusion of additional characters, acknowledgement of character codistribution, and addition of sister clade comparison should be explored to ensure model accuracy. Even so, phylogenies provide a survivor-only examination of character evolution, and paleontological contexts may be necessary to replicate and confirm results. Here, I review these issues in the context of selective brain cooling - a neurovascular-mediated osmoregulatory physiology that dampens hypothalamic responses to heat stress and reduces evaporative water loss in large-bodied mammals. This binary character provides an example of the interplay between sample size, evenness, and character codistribution. Moreover, it allows for an opportunity to compare phylogenetically constrained results with paleontological data, augmenting survivor-only analyses with observable extinction patterns. This trait- dependent diversification example indicates that selective brain cooling is significantly associated with the generation of modern large-mammal faunas. Importantly, paleontological data validate phylogenetic patterns and demonstrate how suites of characters worked in concert to establish the large-mammal communities of today.

中文翻译：

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化石证据增强特质依赖的多样化估计：使用渗透调节性神经脉管系统的案例研究。

当比较神经形态学研究扩展到进化背景时，感兴趣的特征通常与多样化模式相关。与多样化率的提高以及新颖的利基空间的渗透或占领明显相关的特征通常被称为“关键创新”。在过去的十年中，已开发出系统进化的方法来测试关键的创新假设，并评估这些特征对现代动物群形成的影响。这主要是通过估计依赖状态的物种形成和灭绝速率来实现的。这些方法具有与计算和解释相关的重要警告和准则，在研究离散（定性）特征分析的情况下，有必要了解这些准则和准则，这在研究神经形态学演变时很常见。在此类研究中，应探索其他字符的加入，字符共同分布的确认以及姐妹进化枝比较的添加，以确保模型的准确性。即使是这样，系统发育也只能对字符演变进行幸存者检查，古生物学环境对于复制和确认结果可能是必要的。在这里，我将在选择性脑冷却的背景下回顾这些问题，这是一种神经血管介导的渗透调节生理学，可抑制下丘脑对热应激的反应并减少大体哺乳动物的蒸发水分流失。此二进制字符提供了样本大小，均匀性和字符共分布之间相互作用的示例。此外，它还提供了将系统发育受限的结果与古生物学数据进行比较的机会，通过观察到的灭绝模式增强仅幸存者的分析。这个依赖于性状的多样化例子表明，选择性的大脑冷却与现代大型哺乳动物动物的产生显着相关。重要的是，古生物学数据验证了系统发育模式，并证明了一系列字符如何协同作用以建立当今的大型哺乳动物群落。