Proportions between pairs of digits are linked to fitness in tetrapods and they can be influenced by sex hormones through individuals’ ontogenies. Therefore, in many species, the proportions amongst finger length ratios (referred as digit ratio, i.e. 2D second and 4D fourth digits) can differ between males and females. We investigated whether the three most commonly used forelimb digit ratios are sexually dimorphic in three tropidurid species. In one of the three lizard species, Eurolophosaurus nanuzae, males and females differ for only 2D:4D digit ratio. Otherwise, our results on the studied Tropidurus species conform to previous studies showing no differences in digit ratios between males and females. Hence, it might be the case of local selective forces shaping interpopulation variation in the expression of sexual dimorphism for digit ratio.

中文翻译：

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三种拟南芥蜥蜴的数字比

两对数字之间的比例与四足动物的适合度有关，并且它们可能会通过个体的个体发育受到性激素的影响。因此，在许多物种中，男性和女性之间的手指长度比率（称为手指比率，即2D第二和4D第四手指）之间的比例可能有所不同。我们调查了三个拟南芥物种中三个最常用的前肢手指比例是否为性二态。在三种蜥蜴中的一种，欧洲鳞尾蜥，雄性和雌性仅以2D：4D的数字比例不同。否则，我们对拟南芥属物种的研究结果与先前的研究结果一致，表明雄性和雌性之间的数字比例没有差异。因此，可能是局部选择性力在数位比的性二态性表达中影响种群间变异的情况。