The finer points of urban adaptation: intraspecific variation in lizard claw morphology
The finer points of urban adaptation: intraspecific variation in lizard claw morphology
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DOI：
10.1093/biolinnean/blaa123
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发表时间：
2020-10-01
影响因子：
1.9
通讯作者：
Winchell, Kristin M.
中科院分区：
文献类型：
--
作者：
Falvey, Cleo H.;Aviles-Rodriguez, Kevin J.;Winchell, Kristin M.
人类活动极大地改变了景观，产生了物种必须适应的新栖息地。因此，城市化越来越被认为是表型变化的驱动因素。城市栖息地的结构环境提出了一个复制的自然实验，以检查性状-环境关系和与运动相关的表型变异。本文采用几何形态计量学方法研究了城市和森林生境中五种斑蜥的爪部形态。我们发现，城市蜥蜴的爪形在同一方向上发生变化，但不同物种的幅度不同。城市蜥蜴的爪子总体上比森林蜥蜴更高，更少弯曲，更少尖，长度更短。这些差异可以使脚垫在光滑的人造基质上更有效地附着或减少对脚垫功能的干扰。我们还发现，在城市人口中，形状差异（一种衡量变化的指标）有所增加，这表明宽松选择或生态位扩张，而不是定向选择。这项研究扩大了我们对爪形态特征研究相对不足的理解，并增加了越来越多的研究，证明了城市蜥蜴的表型变化。我们观察到的形状变化方向的一致性支持了一个有趣的可能性，即城市环境可能导致可预测的收敛性适应性变化。
Human activity drastically transforms landscapes, generating novel habitats to which species must adaptively respond. Consequently, urbanization is increasingly recognized as a driver of phenotypic change. The structural environment of urban habitats presents a replicated natural experiment to examine trait-environment relationships and phenotypic variation related to locomotion. We use geometric morphometrics to examine claw morphology of five species of Anolis lizards in urban and forest habitats. We find that urban lizards undergo a shift in claw shape in the same direction but varying magnitude across species. Urban claws are overall taller, less curved, less pointed and shorter in length than those of forest lizards. These differences may enable more effective attachment or reduce interference with toepad function on smooth anthropogenic substrates. We also find an increase in shape disparity, a measurement of variation, in urban populations, suggesting relaxed selection or niche expansion rather than directional selection. This study expands our understanding of the relatively understudied trait of claw morphology and adds to a growing number of studies demonstrating phenotypic changes in urban lizards. The consistency in the direction of the shape changes we observed supports the intriguing possibility that urban environments may lead to predictable convergent adaptive change.