Mutation and Levels of Selection in Clonal Organisms

无性繁殖，或新个体的无性繁殖，在植物和动物物种中都很普遍。现有的理论未能充分解决克隆生活史的许多重要细节，包括多级组织的存在和选择的机会。总体目标是扩展进化遗传模型，以纳入这些独特的生活史特征。开发的分析模型将结合种群遗传学框架（例如，跟踪整个种群中的等位基因频率）和人口统计学模型（包含生物体特定生活史的细节）。经验性的人口统计数据将用于进一步的数值分析。为了考虑多层次的选择，个体水平的适应度将反映个体或克隆内突变积累所产生的遗传多样性。模型还将扩展到以其他方式构成的种群（例如，由克隆生长施加的空间结构）。本研究主要有三个独特的优势：(1)将经典群体遗传学理论与人口学模型相结合，可以考虑影响选择的遗传和生态因素；(2)将经验结果与理论模型相结合，可以更好、更现实地理解这些遗传和生态因素；(3)所考虑的生活史特征存在于植物、藻类和至少三分之二的后生动物门中。包括重要的海洋无脊椎动物，如珊瑚，使这项工作的结果广泛适用。通过扩展现有的群体遗传学理论，将先前考虑的生物之外的生物包括在内，拟议的研究将为诸如突变、不同组织水平的选择以及遗传多样性的起源和维持等过程提供重要的见解。

Clonal reproduction, or the nonsexual production of new individuals, is widespread throughout both plant and animal species. Existing theory fails to adequately address many important details of clonal life histories, including the existence of multiple levels of organization and opportunities for selection. The overall aim is to expand evolutionary genetic models to incorporate these unique life history characteristics. Analytical models developed will combine both a population genetics framework (where, for example, allele frequencies in the entire population are followed) and demographic models (which incorporate details of the organism's particular life history). Empirically derived demographic data will be used for further numerical analyses. In order to consider multiple levels of selection, individual-level fitness will reflect genetic diversity generated by the accumulation of mutations within the individual or clone. Models will also be extended to populations that are structured in other ways (for example, spatial structure imposed by clonal growth). There are three major and unique strengths of the proposed research: (1) integration of classical population genetics theory with demographic models allows consideration of both genetic and ecological factors influencing selection, (2) combining empirical results with theoretical models allows a better and more realistic understanding of these genetic and ecological factors, and (3) the life history characteristics being considered are found in plants, in algae, and across at least two-thirds of metazoan animal phyla, including important marine invertebrates such as corals, making the results of this work widely applicable. By expanding existing population genetics theory to include organisms outside of those previously considered, the proposed research will provide crucial insight into processes such as mutation, selection at different levels of organization, and the origin and maintenance of genetic diversity.