Department of Cell Biology and Anatomy, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, LA, 70112, USA.
Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, 02138, USA.
Sci Rep. 2020 Jan 20;10(1):717. doi: 10.1038/s41598-019-57144-w.
Rodents are the most species-rich order within Mammalia and have evolved disparate morphologies to accommodate numerous locomotor niches, providing an excellent opportunity to understand how locomotor innovation can drive speciation. To evaluate the connection between the evolutionary success of rodents and the diversity of rodent locomotor ecologies, we used a large dataset of proximal limb CT scans from across Myomorpha and Geomyoidea to examine internal and external limb shape. Only fossorial rodents displayed a major reworking of their proximal limbs in either internal or external morphology, with other locomotor modes plotting within a generalist morphospace. Fossorial rodents were also the only locomotor mode to consistently show increased rates of humerus/femur morphological evolution. We propose that these rodent clades were successful at spreading into ecological niches due to high behavioral plasticity and small body sizes, allowing them to modify their locomotor mode without requiring major changes to their proximal limb morphology.
啮齿动物是哺乳动物中物种最丰富的目，它们进化出了截然不同的形态结构，以适应众多的运动生态位，为理解运动创新如何推动物种形成提供了极好的机会。为了评估啮齿动物进化成功与啮齿动物运动生态多样性之间的联系，我们使用了来自 Myomorpha 和 Geomyoidea 的大量近端肢体 CT 扫描数据集，以检查内部和外部肢体形状。只有穴居啮齿动物在内部或外部形态上表现出对其近端肢体的重大改造，而其他运动模式则在一般形态空间内绘制。穴居啮齿动物也是唯一一种表现出肱骨/股骨形态进化率持续增加的运动模式。我们提出，这些啮齿动物分支之所以能够成功地扩散到生态位中，是因为它们具有高度的行为可塑性和较小的体型，使它们能够改变其运动模式，而无需对其近端肢体形态进行重大改变。
