Pontzer Herman
Washington University, Department of Anthropology, 119 McMillan Hall, St Louis, MO 63130, USA.
J Exp Biol. 2007 May;210(Pt 10):1752-61. doi: 10.1242/jeb.002246.
Relative to body size, smaller animals use more energy to travel a given distance than larger animals, but the anatomical variable driving this negative allometry remains the subject of debate. Here, I report a simple inverse relationship between effective limb length (i.e. hip height) and the energy cost of transport (COT; J kg(-1) m(-1)) for terrestrial animals. Using published data for a diverse set of terrestrial species including birds, mammals, reptiles and arthropods, I show that between-species differences in locomotor cost are driven by differences in limb length. Notably, there is no independent effect of body mass on cost. Remarkably, effective limb length explains 98% of the observed variance in locomotor cost across a wide range of terrestrial species including mammals, birds, reptiles and arthropods. Variation about the limb-length/COT scaling relationship is attributable to taxonomic differences in limb design, with birds and arthropods exhibiting greater residuals than mammals. Differences in COT between semi-aquatic, generalist and cursorial species also corresponds to differences in leg length between these groups. These results are discussed in light of previous investigations of the limb length and locomotor cost.
相对于体型大小，较小的动物在移动一定距离时比大型动物消耗更多能量，但驱动这种异速生长负相关关系的解剖学变量仍是争论的焦点。在此，我报告了陆生动物有效肢体长度（即臀高）与运输能量成本（COT；焦耳·千克⁻¹·米⁻¹）之间的一种简单反比关系。利用已发表的包括鸟类、哺乳动物、爬行动物和节肢动物等多种陆生物种的数据，我表明运动成本的种间差异是由肢体长度差异驱动的。值得注意的是，体重对成本没有独立影响。显著的是，有效肢体长度解释了包括哺乳动物、鸟类、爬行动物和节肢动物在内的广泛陆生物种中观察到的运动成本方差的98%。肢体长度/COT标度关系的变化归因于肢体设计的分类学差异，鸟类和节肢动物的残差比哺乳动物更大。半水生、多面手和奔跑型物种之间的COT差异也与这些群体之间的腿长差异相对应。根据先前对肢体长度和运动成本的研究对这些结果进行了讨论。
