Theoretical Population and Quantitative Genetics

9527808吉列斯皮许多分子进化研究的目标是了解为什么物种之间和物种内个体之间的遗传物质dna会有如此大的差异。在一种理论中，这种变化的大部分没有功能后果。在这个项目中正在研究的理论中，大多数这种变异确实具有生物学后果。为了了解哪种理论和假设最能描述分子进化，我们将把每种理论的预测与在实际DNA序列中观察到的模式进行比较。这项工作对于了解人类群体中疾病易感性等性状的遗传变异具有潜在的价值。易感性的遗传变异是由于许多小的突变还是几个大的突变？这个项目第二部分的目标是数量遗传学，目的是了解物种内和物种之间可测量的特征(如大小或体重)变异的遗传基础。这项工作中最大的概念性问题是处理许多基因对一个数量性状的综合影响，每个基因的影响都很小。在将要研究的理论中，这些小基因以一种增加了以前模型中缺失的生物学相关性的方式相互作用。一旦这一理论到位，它将被用来研究几个生物学上感兴趣的问题。这项工作对农业将是重要的，因为农业从业者需要更好的关于具有经济重要性的性状的遗传基础的理论，比如牛的产奶量。

9527808 GILLESPIE The goal of many studies of molecular evolution is to understand why there is so much variation in the genetic material, DNA, between species and between individuals within a species. In one theory most of this variation has no functional consequences. In the theory being studied in this project, most of this variation does have biological consequences. To understand which theory and assumptions best describe molecular evolution, the predictions of each theory will be compared with the patterns observed in actual DNA sequences. This work is of potential value for understanding genetic variation in such traits as disease susceptibility in human populations. Is genetic variation in susceptibility due to many small mutations or to a few large ones? The goal of the second part of this project, on quantitative genetics, is to understand the genetic basis of variation in measurable traits, such as size or weight, both within and between species. The great conceptual problem in this work is to deal with the combined effects of many genes, each of small effect, on a quantitative trait. In the theory to be investigated these small genes interact with one another in a way that adds biological relevance that was missing from previous models. Once the theory is in place, it will be used to investigate several problems of biological interest. This work will be important for agriculture, where practitioners require better theories of the genetic basis of traits, such as milk yield in cattle, that are of economic importance.