Reed Courtney G, Swartz Sharon M, Littleford-Colquhoun Bethan L, Florida Madeleine, Torres Logan, Roberts Thomas J, Kartzinel Tyler R
Department of Ecology, Evolution, and Organismal Biology, Brown University, Providence, RI 02912, USA.
Institute at Brown for Environment and Society, Providence, RI 02912, USA.
J Exp Biol. 2025 Feb 1;228(3). doi: 10.1242/jeb.250091. Epub 2025 Feb 13.
Theoretically, animals with longer hindlimbs are better jumpers, while those with shorter hindlimbs are better maneuverers. Yet, experimental evidence of this relationship in mammals is lacking. We compared jump force and maneuverability in a lab population of Mongolian gerbils (Meriones unguiculatus). We hypothesized that gerbils with long legs (ankle to knee) and thighs (knee to hip) would produce the greatest jump forces, while gerbils with short legs and thighs would be able to run most rapidly around turns. Consistent with these hypotheses, gerbils with longer legs produced greater jump forces after accounting for sex and body mass: a 1 mm greater leg length provided 1 body weight unit greater jump force on average. Furthermore, gerbils with shorter thighs were more maneuverable: a 1 mm greater thigh length reduced turn speed by 5%. Rather than a trade-off, however, there was no significant correlation between jump force and turn speed. There was also no correlation between jump force and total hindlimb length, and a weak positive correlation between corner-turning speed and total hindlimb length. These experiments revealed how distinct hindlimb segments contributed in different ways to each performance measure: legs to jumping and thighs to maneuvering. Understanding how variations in limb morphology contribute to overall gerbil locomotor performance may have important impacts on fitness in natural habitats.
从理论上讲，后肢较长的动物更擅长跳跃，而后肢较短的动物则更善于灵活移动。然而，目前尚缺乏关于哺乳动物中这种关系的实验证据。我们在一个实验室饲养的蒙古沙鼠（长爪沙鼠）种群中比较了跳跃力和灵活性。我们假设，腿部（从脚踝到膝盖）和大腿（从膝盖到臀部）较长的沙鼠会产生最大的跳跃力，而腿部和大腿较短的沙鼠在转弯时能够跑得最快。与这些假设一致，在考虑了性别和体重因素后，腿部较长的沙鼠产生了更大的跳跃力：腿部长度每增加1毫米，平均能提供1个体重单位更大的跳跃力。此外，大腿较短的沙鼠更灵活：大腿长度每增加1毫米，转弯速度降低5%。然而，跳跃力和转弯速度之间并没有显著的权衡关系，二者之间没有明显的相关性。跳跃力与后肢总长度之间也没有相关性，而转弯速度与后肢总长度之间存在微弱的正相关。这些实验揭示了不同的后肢节段如何以不同方式对各项性能指标产生影响：腿部影响跳跃，大腿影响灵活性。了解肢体形态的变化如何影响沙鼠的整体运动性能，可能对其自然栖息地中的适应性具有重要影响。
