Analyses of Sexual Size Dimorphism Using Null Growth-Based Models
Analyses of Sexual Size Dimorphism Using Null Growth-Based Models
复制标题
使用基于零增长的模型分析性别大小二态性
作者：
J. Stamps;V. V. Krishnan;R. Andrews
当动物在较小的体型下成熟，然后生长到较大的渐近体型时，许多不同的因素会影响成年雄性和雌性的尺寸分布。本文展示了如何使用基于生长的模型来研究在成熟后具有渐近生长的物种中影响性别大小二型性的因素。基于零生长的模型假设特定样本中的雄性和雌性表现出先前为其分类单元成员描述的生长和成熟模式，并且该样本中的雄性和雌性具有相同的年龄分布。零模型预测的大小分布与样本中观察到的大小分布之间的差异表明，成年年龄分布或特定年龄段的生长轨迹存在显著的性别差异。以Anolis属蜥蜴为例说明了基于零增长的模型的设计和使用。这些分析的结果表明，雄性样本的大小分布往往偏向于比预期更大的雄性，并为行为假说提供了支持，这些假说预测了当雄性竞争繁殖区域时，成年雄性大小分布的扭曲。
When animals mature at small sizes and then grow to larger asymptotic sizes, many different factors can affect adult male and female size distributions. This paper shows how growth-based models can be used to study the factors affecting sexual size dimorphism in species with asymptotic growth after maturity. Null growth-based models assume that the males and females in a particular sample exhibit the growth and maturation patterns previously described for the members of their taxon and that the males and females in that sample have identical age distributions. Discrepancies between the size distributions predicted by the null model and those observed in a sample indicate significant sex differences in adult age distributions or in the growth trajectories of particular age classes. The design and use of null growth-based models is illustrated using lizards of the genus Anolis. The results of these analyses show that samples of anoles often have male size distributions skewed in favor of larger-than-expected males and provide support for behavioral hypotheses that predict skewed adult male size distributions when males compete for breeding territories.