Analysis of coevolution and sexual dimorphism by comparative methods based on phylogenetic trees.

利用系统发育树分析了寄主植物与植食性昆虫的共进化、蚜虫等社会性昆虫的社会行为进化、性分配和性二型性的进化。在寄主植物与草食动物的协同进化中，我们重点研究了豆科植物与其食草动物豆象之间的关系。构建了两种生物的分子遗传学。对豆象寄主利用的野外调查表明，分枝较早的两个植物亚科的豆象种类较多，但这种差异是由于木本植物比草本植物的豆象种类较多所致。分析了豆象生理适应对寄主利用和植物防御豆象危害的影响。利用系统发育树分析了单食性和腐食性的进化。在性二型性的进化方面，我们利用mtDNA对蜻蜓和豆娘进行了分子遗传学研究，并利用广义简约法构建了分子遗传学模型。对于植物的性分配，采用Felsenstein的独立对比方法对纳入库源关系的理论模型的预测进行了检验。测试结果与预测一致。特别是对于皇后数的演化，几乎完全解决的遗传问题是必要的，以测试假设，作出相互矛盾的预测。可用的系统发育信息，特别是分支长度的信息，决定了可以使用的比较方法。离散比较数据的方法也进行了检查。

Coevoiution of host plants and herbivores, evolution of social behavior in social insects including aphids with soldiers and evolution of sexual allocation and sexual dimorphism were analyzed by comparative methods with phylogenetic trees. In the coevolution of host plants and herbivorous animals, we focused on the relationship between legumes and their herbivores, bruchid beetles. Molecular phylogenies of both organisms were constructed. Field surveys of host utilization by the bruchid beetles showed that species of two plant subfamilies that had branched earlier had a larger number of species of the bruchid beetles.However, this difference was explained by the effect that woody plant species had a arger number of the bruchid beetle species than herbs. The effect of physiological adaptation of the beetles for host utilization and defense of plants against attacks by the bruchid beetles were analyzed. Evolution of monophagy in butterflies and that of saprophagy were also analyzed with phylogenetic trees. For the evolution of sexual dimorphism, we made the molecular phylogeny of dragonfly and damselfly species by using mtDNA.Generalized parsimony was used to construct the molecular phylogeny. For sexual allocation in plants, the predictions by theoretical models that incorporated the sink-source relationship were tested by Felsenstein's independent contrast method. The results of the tests were consistent with the predictions. For the evolution of queen numbers in particular, almost fully resolved phylogenies were necessary to test hypotheses that made conflicting predictions. The available phylogenetic information, information of branch length in particular, determines the comparative methods that can be used. Methods for discrete comparative data were alsoexamined.