Machado Fabio Andrade, Zahn Thiago Macek Gonçalves, Marroig Gabriel
División Mastozoologa, Museo Argentino de Ciencias Naturales, "Bernardino Rivadavia". Av. Ángel Gallardo 470 (C1405DJR), Buenos Aires, Argentina.
Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina.
Evolution. 2018 May 26. doi: 10.1111/evo.13495.
Morphological integration refers to the fact that different phenotypic traits of organisms are not fully independent from each other, and tend to covary to different degrees. The covariation among traits is thought to reflect properties of the species' genetic architecture and thus can have an impact on evolutionary responses. Furthermore, if morphological integration changes along the history of a group, inferences of past selection regimes might be problematic. Here, we evaluated the stability and evolution of the morphological integration of skull traits in Carnivora by using evolutionary simulations and phylogenetic comparative methods. Our results show that carnivoran species are able to respond to natural selection in a very similar way. Our comparative analyses show that the phylogenetic signal for pattern of integration is lower than that observed for morphology (trait averages), and that integration was stable throughout the evolution of the group. That notwithstanding, Canidae differed from other families by having higher integration, evolvability, flexibility, and allometric coefficients on the facial region. These changes might have allowed canids to rapidly adapt to different food sources, helping to explain not only the phenotypic diversification of the family, but also why humans were able to generate such a great diversity of dog breeds through artificial selection.
形态整合是指生物体的不同表型特征并非完全相互独立，而是倾向于不同程度地共同变化。性状之间的共同变化被认为反映了物种遗传结构的特性，因此可能会对进化反应产生影响。此外，如果形态整合在一个类群的历史中发生变化，那么对过去选择机制的推断可能会出现问题。在这里，我们通过使用进化模拟和系统发育比较方法，评估了食肉目动物头骨性状形态整合的稳定性和进化。我们的结果表明，食肉目物种能够以非常相似的方式对自然选择做出反应。我们的比较分析表明，整合模式的系统发育信号低于形态学（性状平均值）所观察到的信号，并且在该类群的整个进化过程中整合是稳定的。尽管如此，犬科动物与其他科不同，其面部区域具有更高的整合度、进化能力、灵活性和异速生长系数。这些变化可能使犬科动物能够迅速适应不同的食物来源，这不仅有助于解释该科的表型多样化，也解释了为什么人类能够通过人工选择培育出如此多样的犬种。
