Department of Biology, University of Massachusetts Boston, 100 Morrissey Blvd., Boston, MA 02125, USA
Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford Street, Cambridge, MA 02138, USA.
Proc Biol Sci. 2018 Jun 13;285(1880). doi: 10.1098/rspb.2018.0229.
Urban habitats are drastically modified from their natural state, creating unique challenges and selection pressures for organisms that reside in them. We compared locomotor performance of lizards from urban and forest habitats on tracks differing in angle and substrate, and found that using artificial substrates came at a cost: lizards ran substantially slower and frequently lost traction on man-made surfaces compared to bark. We found that various morphological traits were positively correlated with sprint speed and that these same traits were significantly larger in urban compared to forest lizards. We found that urban lizards ran faster on both man-made and natural surfaces, suggesting similar mechanisms improve locomotor performance on both classes of substrate. Thus, lizards in urban areas may be under selection to run faster on all flat surfaces, while forest lizards face competing demands of running, jumping and clinging to narrow perches. Novel locomotor challenges posed by urban habitats likely have fitness consequences for lizards that cannot effectively use man-made surfaces, providing a mechanistic basis for observed phenotypic shifts in urban populations of this species.
城市生境与自然状态相比发生了巨大的改变，这对生活在其中的生物构成了独特的挑战和选择压力。我们比较了来自城市和森林生境的蜥蜴在不同角度和基质的轨道上的运动表现，发现使用人造基质是有代价的：与树皮相比，蜥蜴在人造表面上的跑动速度明显更慢，并且经常失去抓地力。我们发现，各种形态特征与冲刺速度呈正相关，而这些特征在城市蜥蜴中比在森林蜥蜴中明显更大。我们发现，城市蜥蜴在人造和自然表面上跑得都更快，这表明类似的机制可以提高在这两类基质上的运动表现。因此，城市地区的蜥蜴可能面临着在所有平坦表面上跑得更快的选择压力，而森林蜥蜴则面临着在狭窄栖木上跑动、跳跃和抓握的竞争需求。城市生境带来的新的运动挑战可能对不能有效利用人造表面的蜥蜴有适应方面的影响，为观察到该物种在城市种群中的表型变化提供了一个机械基础。
