Sensitivity of intraspecific latitudinal clines of body size for tetrapods to sampling, latitude and body size
Sensitivity of intraspecific latitudinal clines of body size for tetrapods to sampling, latitude and body size
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DOI：
10.1093/icb/44.6.403
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发表时间：
2004-12-01
影响因子：
2.6
通讯作者：
Ashton, KG
中科院分区：
文献类型：
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作者：
Ashton, KG
最近的研究表明，大多数四足动物（哺乳动物，鸟类，龟类，两栖动物）显示出一般的种内趋势，随着纬度增加身体大小，而有鳞动物（蜥蜴和蛇）显示出种内趋势，随着纬度减少身体大小。在这里，我评估这些大小的趋势是否是一般的，通过使用独立的对比分析，调查的依赖种内大小-纬度关系（r），大小-纬度关系（[r]），四足脊椎动物，样本大小，纬度范围采样，平均纬度采样，和身体大小。采样纬度范围、采样平均纬度和个体大小对个体大小-纬度关系（r）或个体大小-纬度关系（[r]）没有影响。样本量不影响大小-纬度关系（r），但影响大小-纬度关系（[r]）的大小，可能表明随着采样的增加，估计大小-纬度关系的精度增加。简而言之，对于不同大小的物种来说，种内大小-纬度关系是相似的，发生在不同的纬度，在不同的纬度范围内取样，并且在取样的种群数量上不同（尽管大小本身受到样本大小的影响）。这些结果表明，种内大小-纬度趋势是普遍的，并且具有生物学意义（即，不是采样的工件），因此值得解释。
Recent studies have shown that most tetrapod groups (mammals, birds, chelonians, amphibians) show general intraspecific tendencies for increasing body size with latitude, whereas squamates (lizards and snakes) show an intraspecific tendency towards decreasing body size with latitude. Here I evaluate whether these size trends are general by using independent contrasts analysis to investigate the dependence of intraspecific size-latitude relationships (r), and the magnitude alone of size-latitude relationships ([r]), for tetrapod vertebrates, on sample size, range of latitudes sampled, average latitude sampled, and body size. Range of latitudes sampled, average latitude sampled, and body size did not influence body size-latitude relationships (r) or the magnitude alone of body size-latitude relationship ([r]). Sample size did not influence size-latitude relationships (r), but did influence the magnitude alone of size-latitude relationships ([r]), possibly indicating increased precision of estimating size-latitude relationships with increased sampling. In short, intraspecific size-latitude relationships are similar for species of different sizes, occurring at different latitudes, sampled over different latitudinal ranges, and differing in number of populations sampled (though magnitude alone is influenced by sample size). These results suggest that intraspecific size-latitude trends are general, and biologically significant (i.e., are not artifacts of sampling), thus deserving explanation.