Evolutionary dynamics of covariation patterns in craniometric traits was studied for bats from the Myotis myotis–Myotis blythii species group (Mammalia, Chiroptera, Vespertilionidae) namely M.m.myotis, M.b.oxygnathus, M.b.omari, M.b.blythii, and M.b.altaicus. These species evolved towards increasing the size. One more species, M.dasycneme, which is phylogenetically, morphologically, and ecologically rather distant from these OTUs, also was studied for comparison with them. A set of 30 craniometric traits was studied for each of the OTUs using the quantitative genetics approaches. Phenotypic covariance matrices were used as proxies for additive genetic covariance matrices. The analysis has shown that multivariate divergence of the studied Myotis OTUs was governed by selection rather than by random drift and that these OTUs evolved in the direction close to the line of least evolutionary resistance. As overall size increases, the skull integration, respondability, and evolvability increase, while flexibility slightly decreases. Such a pattern can possibly be explained as a consequence of adaptation of M.blythii and especially M.myotis to prey on considerably large hard-shelled insects. A high cohesion of skull structures is needed for the effective functioning of their jaw apparatus. For Myotis bats with other foraging strategies (such as M. dasycneme that catches insects mainly using the claws of hind feet) this cohesion seems to be of lesser importance.

中文翻译：

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沿着最小抗性遗传系进化的自然选择可能会影响自然进化中的Myotis myotis – Myotis blythii物种组（Vespertilionidae，Chiroptera）的头骨整合模式和内部约束。

在craniometric性状共变图案进化动力学进行了研究用于从蝙蝠鼠耳鼠耳-鼠耳blythii种组（哺乳纲，翼手目，Vespertilionidae）即M.米。鼠耳蝠，M.湾 oxygnathus，M 。奥马里，M.湾 blythii，和M.湾 阿尔泰克斯。这些物种进化为增加大小。一个种类比较多，M. dasycneme与这些OTU在系统发育，形态和生态上相距较远的地方，也进行了研究，以与它们进行比较。使用定量遗传学方法对每个OTU进行了30种颅骨测量性状的研究。表型协方差矩阵用作加性遗传协方差矩阵的代理。分析表明，研究的Myotis OTU的多元发散性是由选择而不是由随机漂移决定的，并且这些OTU在接近最小进化阻力线的方向上进化。随着整体尺寸的增加，头骨的整合，响应能力和可进化性会增加，而柔韧性会略有下降。这种模式可能可以解释为M. blythii的结果尤其是Myotis M. myotis捕食相当大的硬壳昆虫。颅骨结构需要高内聚力才能有效发挥其颌骨器械的功能。对于具有其他觅食策略的Myotis蝙蝠（例如主要通过后足爪抓捕昆虫的达氏甲烷八叠球菌），这种内聚力似乎不太重要。