Klingenberg Christian Peter, McIntyre Grant S
Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada.
Department of Zoology, Duke University, Durham, North Carolina, 27708-0325.
Evolution. 1998 Oct;52(5):1363-1375. doi: 10.1111/j.1558-5646.1998.tb02018.x.
Although fluctuating asymmetry has become popular as a measure of developmental instability, few studies have examined its developmental basis. We propose an approach to investigate the role of development for morphological asymmetry by means of morphometric methods. Our approach combines geometric morphometrics with the two-way ANOVA customary for conventional analyses of fluctuating asymmetry and can discover localized features of shape variation by examining the patterns of covariance among landmarks. This approach extends the notion of form used in studies of fluctuating asymmetry from collections of distances between morphological landmarks to an explicitly geometric concept of shape characterized by the configuration of landmarks. We demonstrate this approach with a study of asymmetry in the wings of tsetse flies (Glossina palpalis gambiensis). The analysis revealed significant fluctuating and directional asymmetry for shape as well as ample shape variation among individuals and between the offspring of young and old females. The morphological landmarks differed markedly in their degree of variability but multivariate patterns of landmark covariation identified by principal component analysis were generally similar between fluctuating asymmetry (within-individual variability) and variation among individuals. Therefore there is no evidence that special developmental processes control fluctuating asymmetry. We relate some of the morphometric patterns to processes known to be involved in the development of fly wings.
尽管波动不对称性已成为衡量发育不稳定性的常用指标，但很少有研究探讨其发育基础。我们提出一种方法，通过形态测量学方法来研究发育对形态不对称性的作用。我们的方法将几何形态测量学与传统波动不对称性分析中常用的双向方差分析相结合，通过检查地标间的协方差模式来发现形状变化的局部特征。这种方法将波动不对称性研究中使用的形态概念从形态地标间距离的集合扩展到由地标配置表征的明确的几何形状概念。我们通过对采采蝇（冈比亚舌蝇）翅膀不对称性的研究来证明这种方法。分析揭示了形状的显著波动不对称性和方向性不对称性，以及个体之间和年轻与年老雌性后代之间丰富的形状变化。形态地标在变异性程度上有显著差异，但主成分分析确定的地标协方差多变量模式在波动不对称性（个体内变异性）和个体间变异方面通常相似。因此，没有证据表明特殊的发育过程控制波动不对称性。我们将一些形态测量模式与已知参与蝇类翅膀发育的过程联系起来。
