Abstract—

Methods of geometric morphometrics have been used to assess chronographic variation of morphofunctional traits in the same cenopopulations of the bank vole (Clethrionomys glareolus) and pigmy wood mouse (Sylvaemus uralensis) in Orenburg oblast. Changes in the mandible size and shape and in morphofunctional mandibular indices that occurred over 30 years (1986–2016) have been evaluated. As a result, directional shifts in morphogenesis of the mandible and its morphofunctional transformations related to change in trophic preferences have been revealed in both voles and mice. The mandible shape has changed toward specialization for food gnawing and crushing in C. glareolus cenopopulation and for transverse food grinding in S. uralensis cenopopulation. Sexual dimorphism in the mandible centroid size (CS) in both species has increased over the 30-year period, whereas the parameter of morphological disparity (MNND) has decreased significantly, providing indirect evidence for an increase in developmental stability. Despite a shift in climatic regime and associated changes in vegetation, parallelism of chronographic variation has been revealed in the two taxonomically distant species, reflecting a high and positive coevolutionary potential, i.e., similar morphogenetic responses to changes in environmental conditions in different years. These results show that rapid directional modifications of morphogenesis actually occur in cenopopulations of sympatric rodent species under climate change.

中文翻译：

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两种同伴啮齿类动物物种的形态特征在形态特征上的时间变化耦合。

摘要-

几何形态计量学的方法已被用于评估奥伦堡州的田鼠（Clethrionomys glareolus）和矮木鼠（Sylvaemus uralensis）的同一个种群中形态功能性状的时序变化。已评估了30年（1986-2016年）发生的下颌骨大小和形状以及形态功能下颌指数的变化。结果，在田鼠和小鼠中都揭示了下颌骨形态发生的方向性转变及其与营养偏好改变有关的形态功能转变。下颌骨的形状具有朝向专业化改变食品咬和在破碎C. glareolus cenopopulation和横向食品在磨削S.甘草人口众多。在过去的30年中，两个物种的下颌骨质心大小（CS）的性二态性均增加，而形态差异（MNND）的参数已显着降低，这为发育稳定性的增加提供了间接证据。尽管气候状况发生了变化，植被也发生了相应的变化，但在两个分类学上相距遥远的物种中却发现了时间变化的平行性，反映出高正的协同进化潜力，即对不同年份环境条件变化的相似形态发生响应。这些结果表明，在气候变化下，同伴啮齿动物物种的孢子群实际上发生了形态发生的快速定向修饰。