Experimental and Theoretical Studies of the Coevolution of Inbreeding Depression and Mating System

9707684近亲个体之间的交配通常会导致近亲繁殖衰退，或产生质量较低的后代。该项目探讨了近亲繁殖抑制时交配系统的进化，以及交配系统的进化。理论分析表明，近亲繁殖抑制的惩罚在实行不同水平近亲繁殖的家族谱系中演变成不同的程度。这种相互作用的可能后果之一是混合交配系统的进化，这既需要近亲繁殖，也需要近亲繁殖。曼陀罗的自然种群实行混合交配系统，为直接探索这些问题提供了一个模式系统。以前的工作已经证明，形态特征(柱头-花药距离)既是可遗传的，也是个体近亲交配水平的决定因素。近亲繁殖衰退的严重程度将在单个家庭中进行估计。这个系统允许测试家庭水平的近亲繁殖抑制是否与交配系统有关。此外，还将进行数值模拟研究，以探索近亲繁殖抑制和家族血统之间的各个方面的关联，包括它们的遗传基础和对交配系统进化的影响。所有活着的有机体都会受到突变的有害影响。影响突变负荷产生、清除和维持的过程直接影响生命的长度和质量。理论和经验研究已经证实，交配制度是自然种群近亲繁殖衰退的主要决定因素和结果。

9707684 Uyenoyama Mating between closely related individuals often results in inbreeding depression, or the production of offspring of lower quality. This project addresses the evolution of mating systems in response to inbreeding depression and its evolution in turn in response to the mating system. Theoretical analyses suggest that the penalty of inbreeding depression evolves to different magnitudes among familial lineages that practice different levels of inbreeding. Among the possible consequences of such interactions is the evolution of mixed mating systems, which entail both inbreeding and outbreeding. Natural populations of Datura stramonium, which practices a mixed mating system, provide a model system for the direct exploration of these issues. Previous work has demonstrated that a morphological character (stigma-anther distance) is both heritable and a determinant of the level of inbreeding in individuals. The magnitude of inbreeding depression will be estimated in individual families. This system permits a test of whether inbreeding depression at the family level is associated with mating system. In addition, numerical simulation studies will be conducted to explore various aspects of associations between inbreeding depression and familial lineage, including their genetic bases and consequences for the evolution of mating systems. All living organisms are subject to the deleterious effects of mutations. Processes that influence the generation, purging, and maintenance of mutational load directly affect the length and quality of life. Theoretical and empirical studies have established mating system as a major determinant as well as a consequence of inbreeding depression in natural populations.