Centre for Conservation Biology, Department of Biology, University of Science and Technology NTNU, 7491 Trondheim, Norway.
Am Nat. 2013 Feb;181(2):195-212. doi: 10.1086/668820. Epub 2013 Jan 14.
Ontogenetic and static allometries describe how a character changes in size when the size of the organism changes during ontogeny and among individuals measured at the same developmental stage, respectively. Understanding the relationship between these two types of allometry is crucial to understanding the evolution of allometry and, more generally, the evolution of shape. However, the effects of ontogenetic allometry on static allometry remain largely unexplored. Here, we first show analytically how individual variation in ontogenetic allometry and body size affect static allometry. Using two longitudinal data sets on ontogenetic and static allometry, we then estimate variances and covariances for the different parameters of the ontogenetic allometry defined in our model and assess their relative contribution to the static allometric slope. The mean ontogenetic allometry is the main parameter that determines the static allometric slope, while the covariance between the ontogenetic allometric slope and body size generates most of the discrepancies between ontogenetic and static allometry. These results suggest that the apparent evolutionary stasis of the static allometric slope is not generated by internal (developmental) constraints but more likely results from external constraints imposed by selection.
个体发生和静态生长分析分别描述了在个体发育过程中生物体大小的变化，以及在相同发育阶段测量的个体之间的大小变化。了解这两种生长分析之间的关系对于理解生长分析的进化，更普遍地说，对于理解形状的进化至关重要。然而，个体发生生长分析对静态生长分析的影响在很大程度上仍未得到探索。在这里，我们首先分析性地展示了个体发生生长分析和体型的个体变异如何影响静态生长分析。然后，我们使用两个关于个体发生和静态生长分析的纵向数据集，估计了我们模型中定义的个体发生生长分析不同参数的方差和协方差，并评估了它们对静态生长斜率的相对贡献。平均个体发生生长分析是决定静态生长斜率的主要参数，而个体发生生长斜率和体型之间的协方差则产生了个体发生和静态生长分析之间的大部分差异。这些结果表明，静态生长斜率的明显进化停滞不是由内部（发育）约束产生的，而更可能是由选择施加的外部约束造成的。
