Theoretical study of a role of evolution of intraspecific interactions in origination and maintenance of biodiversity

该项目的研究可以分为两类，即关于生物多样性的宏观研究和微观研究。第一个宏观研究是关于一个捕食者-两个食饵系统中防御进化和最优食物选择对种群动态影响的理论研究。在这项研究中，揭示了有关物种的进化和行为变化既促进了系统的稳定，也促进了物种的共存。第二个宏观研究是放牧压力下一年生植物的最佳物候分析。这项研究表明，植物的生长进程可能会因与食草动物的相互作用而变化。这为理解植物-食草动物相互作用的特性提供了基本信息，这些特性是物种多样性的基础。另一方面，从微观角度的第一个研究是从线粒体到核的基因转移速率的研究。线粒体最初是自由生活的细菌，它取代了…更常成为真核生物的胞内共生体。我分析了一个进化过程，在这个过程中，线粒体与宿主实现了紧密的互惠互利。这项研究包括对建立互惠关系的研究的各种建议，这些关系是生物多样性的重要组成部分。第二个微观研究是对蚂蚁对称性社会杂交发生的持续条件的分析。在这项研究中，我们分析了在特定蚂蚁物种中控制种姓决定的等位基因的遗传动力学。分析阐明了这些等位基因多态的条件，这导致了种群中种姓的共存，使系统得以持久存在。对相互作用等位基因遗传动力学的研究可以作为分析相互作用物种进化的基础。根据这些研究，清楚地表明物种之间的相互作用是可变的，伴随着系统性质的变化，在某些情况下可以稳定系统的行为。较少

The studies of this project can be classified into two categories, macro-and microscopic studies about biodiversity. The first macroscopic study is a theoretical study of effect of defense evolution and optimal diet choice on population dynamics in one predator-two prey system. In this study, it was revealed that evolutionary and behavioral changes of the concerned species facilitate both stability of the system and coexistence of species. The second macroscopic study is an analysis of optimal phenology of annual plants under grazing pressure. This study indicated that the growth schedule of plant possibly varies, responding to interactions with herbivore animals. This provides basic information to understand properties of plant-herbivore interactions that are fundamental for the species diversity.On the other hand, the first study from the microscopic viewpoint is a study of gene transfer rate from mitochondria to nuclear. Mitochondria were originally free-living bacteria, which subse … More quently became an intracellular symbiont of eukaryote. I analyzed an evolutionary process, during which mitochondria have achieved tight mutualism with their hosts. This study included various suggestions for studies of establishments of mutualistic relationships that are essential component of biodiversity. The second microscopic study is an analysis of persistence condition of symmetric social hybridogenesis in ants. In this study, we analyzed genetic dynamics of alleles that controlled the caste determination in a certain ant species. The analysis clarified conditions for polymorphism of those alleles, which results in a co-presence of castes in a population, enabling a persistence of the system. Such a study of genetic dynamics of interacting alleles can be a basis of analyses of evolution of interacting species.According to these studies, it was clearly indicated that interactions among species were variable, accompanied by alternation of system properties, which can stabilize the behavior of system in some situations. Less