REU: Genetic Variability in Bryophyte Populations

性的进化意义是人类进化史上的一个核心问题， 进化生态学 已经有了大量的模型 它预测了有性与无性的相对优势 复制，但很少有实证检验存在。 这个目标 研究就是提供这样一个测试，使用森林 bragiente、透明四棘鲀Tetrapis pellucida. 苔藓植物是理想的系统， 这是为了测试关于性行为有效性的假设， 或无性繁殖，因为它们 表现出高度的栖息地特异性和广泛的 生殖方式 研究表明，遗传变异的水平 在某些无性繁殖的物种中， 物种 无性繁殖不一定产量减少 遗传变异，特别是在那些生物体中， 生殖系不是孤立的体细胞突变。 传统 认为性通过创造基因增强健康 多样性可能不适用于布鲁塞尔。 这项研究的长期目标是检查 体细胞非生殖细胞突变，作为一种来源， 遗传变异性，可能等于或超过性 苔藓中的重组 某些背景信息是 在进行这样的调查之前。 本研究规划 格兰特将允许金默勒博士完成初步研究 并制定支持长期目标的方法。 在此提议的活动是为下列活动作必要的准备： 一项重大的研究成果

The evolutionary significance of sex is a central problem in evolutionary ecology. There has been a proliferation of models which predict the relative benefits of sexual vs. asexual reproduction but few empirical tests exist. The goal of this research is to provide just such a test, using the forest bryophyte, Tetraphis pellucida. Bryophytes are ideal systems in which to test hypotheses concerning the effectiveness of sexual or asexual reproduction in different environments since they exhibit a high degree of habitat specificity and wide array of reproductive modes. It has been demonstrated that levels of genetic variability in some asexual species are equivalent to those of sexual species. Asexual reproduction does not necessarily yield reduced genetic variability, especially in those organisms in which the germ line is not isolated from somatic mutation. The traditional view that sex enhances fitness through the creation of genetic diversity may be inappropriate in bryophytes. The long-term goal of this research is to examine the possibility that somatic non-germ cell mutation, as a source of genetic variability, may equal or exceed that of sexual recombination in mosses. Certain background information is required prior to such an investigation. This Research Planning Grant would permit Dr. Kimmerer to complete preliminary studies and to develop methods which would support the long-term goal. The activities proposed here constitute essential preparation for a major research effort.