Accelerated Brain Shape Evolution Is Associated with Rapid Diversification in an Avian Radiation
Accelerated Brain Shape Evolution Is Associated with Rapid Diversification in an Avian Radiation
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DOI：
10.1086/713664
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发表时间：
2021-05-01
影响因子：
2.9
通讯作者：
Hackett, Shannon J.
中科院分区：
文献类型：
--
作者：
Eliason, Chad M.;McCullough, Jenna M.;Hackett, Shannon J.
生态位扩展是物种形成过程中的关键步骤。与认知能力提高相关的大大脑可能使物种能够扩大其生态位并以新的方式觅食，从而促进物种形成。尽管人们对大脑大小的生态差异及其在物种形成中的重要性进行了大量研究，但人们对大脑形状如何与宏观进化尺度的行为、生态和分类多样性之间的关系知之甚少。这在一定程度上是由于量化许多物种的大脑形状所面临的固有挑战。在这里，我们提出了一种新颖的半自动化方法，使用从 X 射线计算机显微断层扫描中获得的半地标来快速对大脑形状进行表型分析。然后，我们通过解析各种鸟类的进化趋势来测试其实用性：翠鸟（鸟纲：Alcedinidae）。多变量比较分析表明，大脑形状进化率（但不是喙形状）与谱系多样化率呈正相关。独特的大脑形状进一步与身体大小和觅食行为的变化相关，这表明异速生长和生态对大脑形状进化的限制。这些结果符合大脑作为物种形成关键过程（例如扩散、觅食行为和饮食生态位）“主调节器”的想法。
Niche expansion is a critical step in the speciation process. Large brains linked to improved cognitive ability may enable species to expand their niches and forage in new ways, thereby promoting speciation. Despite considerable work on ecological divergence in brain size and its importance in speciation, relatively little is known about how brain shape relates to behavioral, ecological, and taxonomic diversity at macroevolutionary scales. This is due in part to inherent challenges with quantifying brain shape across many species. Here we present a novel, semiautomated approach for rapidly phenotyping brain shape using semilandmarks derived from X-ray computed microtomography scans. We then test its utility by parsing evolutionary trends within a diverse radiation of birds: kingfishers (Aves: Alcedinidae). Multivariate comparative analyses reveal that rates of brain shape evolution (but not beak shape) are positively correlated with lineage diversification rates. Distinct brain shapes are further associated with changes in body size and foraging behavior, suggesting both allometric and ecological constraints on brain shape evolution. These results are in line with the idea of brains acting as a "master regulator" of critical processes governing speciation, such as dispersal, foraging behavior, and dietary niche.