BODY SIZE IN ISLAND LIZARDS - CAUTIONARY TALE
BODY SIZE IN ISLAND LIZARDS - CAUTIONARY TALE
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DOI：
10.2307/1938236
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发表时间：
1978-01-01
期刊：
影响因子：
4.8
通讯作者：
GIBBONS, JW
中科院分区：
文献类型：
--
作者：
DUNHAM, AE;TINKLE, DW;GIBBONS, JW
乌塔属蜥蜴标本[U]。秀丽隐杆线虫（stansburiana elegans）、美国泰洛丽虫（us taylori）、美国palmeri、美国安提瓜虫（us antigua）、美国nolascensis虫（us nolascensis）和美国squamata虫（us squamata）都是从加利福尼亚湾的许多岛屿上收集到的。同时采集与Uta共存的其他种类蜥蜴。这些样本为详细分析每个岛屿uta种群的体型和性别二态性程度以及体型与许多独立变量（如潜在竞争物种的数量和丰度）的相关性提供了数据。本研究验证了一个零假设，即在特定岛屿上，竞争物种[Callisaurus、Cnemidophorus hyperythrus、Vrosaurus、Cnemidophorus spp、Sceloporus spp、Crotaphytus spp、Petrosaurus、Dipsosaurus、Sauromalus和Ctenosaura]对utas的体型和性别二态性没有显著影响。这一普遍假设的各种推论也得到了检验。研究结果支持了没有竞争效应的原假设，并证明了与竞争不明显相关的自变量至少与与竞争直接相关的变量一样多地解释了Uta体型的差异。以往关于岛蜥蜴体型进化的研究已经成为推测体型与种间竞争强度之间因果关系的范例。这项研究邀请谨慎的间接类型的方法来研究竞争在这些以前的研究中使用。讨论了以往研究方法的不足，并提出了更好的竞争研究方法。选择压力对生物体体型的影响可能至少与来自其他物种的竞争一样大。
Samples of lizards of the genus Uta [U. stansburiana elegans, U. s. taylori, U. palmeri, U. antigua, U. nolascensis and U. squamata] were collected from many of the islands in the Gulf of California. Other species of lizards coexisting with Uta were collected simultaneously. These samples provided data for a detailed analysis of body size and degree of sexual dimorphism in each island uta population and the correlation of body size with numerous independent variables such as the number and abundance of potentially competing species. This study tested the null hypothesis that competing species [Callisaurus, Cnemidophorus hyperythrus, Vrosaurus, Cnemidophorus spp., Sceloporus spp., Crotaphytus spp., Petrosaurus, Dipsosaurus, Sauromalus and Ctenosaura] had no significant influence on the body size or sexual dimorphism of the utas on particular islands. Various corollaries of this general hypothesis were also tested. The results supported the null hypothesis of no competitive effect and demonstrated that independent variables not obviously associated with competition explained at least as much of the variance in Uta body size as did variables directly related to competition. Previous studies on the evolution of body size in insular lizards have become paradigms of a presumed causal relationship between body size and intensity of interspecific competition. This study invites caution to the indirect type of approach to the study of competition used in these previous studies. The weakness of past approaches are discussed and better approaches to the study of competition are suggested. Selective pressures that might have at least as great an effect on body size of organisms as does competition from other species are identified.