Klingenberg C P, Zaklan S D
Department of Zoology, Duke University, Durham, North Carolina 27708-0325, USA.
Evolution. 2000 Aug;54(4):1273-85. doi: 10.1111/j.0014-3820.2000.tb00560.x.
Developmental integration is the covariation among morphological structures due to connections between the developmental processes that built them. Here we use the methods of geometric morphometrics to study integration in the wing of Drosophila melanogaster. In particular, we focus on the hypothesis that the anterior and posterior wing compartments are separate developmental units that vary independently. We measured both variation among genetically diverse individuals and random differences between body sides of single individuals (fluctuating asymmetry, FA). For both of these sources of variation, the patterns of variation identified by principal component analyses all involved landmarks in both the anterior and posterior compartments simultaneously. Analyses focusing exclusively on the covariation between the anterior and posterior compartments, by the partial least-squares method, revealed pervasive integration of the two compartments, for both individual variation and FA. These analyses clearly indicate that the anterior and posterior compartments are not separate units of variation, but that the covariation between compartments is sufficient to account for nearly all the variation throughout the entire wing. We conclude that variation among individuals as well as the developmental perturbations responsible for FA generate shape variation primarily through developmental processes that are integrated across both compartments. In contrast, much less of the shape variation in our sample can be attributed to the localized processes that establish the identity of particular wing veins.
发育整合是指由于构建形态结构的发育过程之间的联系，导致形态结构之间的协变。在这里，我们使用几何形态测量学方法来研究黑腹果蝇翅膀的整合情况。具体而言，我们关注这样一个假设：翅膀的前后区室是独立发育的单位，它们各自独立变化。我们测量了遗传多样性个体之间的变异以及单个个体身体两侧的随机差异（波动不对称性，FA）。对于这两种变异来源，主成分分析所识别的变异模式均同时涉及前后区室的标志点。通过偏最小二乘法专门针对前后区室之间的协变进行分析，结果显示，对于个体变异和波动不对称性而言，两个区室都存在广泛的整合。这些分析清楚地表明，前后区室并非独立的变异单位，而是区室之间的协变足以解释整个翅膀几乎所有的变异。我们得出结论，个体间的变异以及导致波动不对称性的发育扰动主要通过跨两个区室整合的发育过程产生形状变异。相比之下，我们样本中形状变异的很大一部分不能归因于确定特定翅脉特征的局部过程。
