DETECTING ADAPTIVE EVOLUTION IN THE CONTEXT OF LINKED DELETERIOUS MUTATIONS

描述(由申请人提供)： 我们对分子进化的理解依赖于我们识别适应性替换并估计它们在基因组中的频率的能力。许多中立性的统计检验已经被用来检测适应性进化，这些检验在基因组序列变异中的应用已经提供了强有力的证据来反对分子进化的中性理论。然而，我们检测正向选择并估计其在基因组中的频率的能力可能在不知不觉中受到有害突变的影响。首先，优势等位基因在人群中的传播可能会导致连锁有害突变的固定，导致对适应性替代频率的高估。其次，有害的突变可能会干扰有利等位基因在群体中的传播，导致连锁中性变异的模式发生变化。这项拟议的研究的目标是使用计算机模拟来调查有害突变显著改变我们识别和估计适应性进化频率的能力的条件。

DESCRIPTION (provided by applicant): Our understanding of molecular evolution depends on our ability to identify adaptive substitutions and estimate their frequency in the genome. Numerous statistical tests of neutrality have been developed to detect adaptive evolution and application of these tests to genome sequence variation has provided strong evidence against the neutral theory of molecular evolution. Yet, our ability to detect positive selection and estimate its frequency in the genome may be unknowingly affected by deleterious mutations. First, the spread of an advantageous allele through a population may cause the fixation of linked deleterious mutations, leading to overestimates of the frequency of adaptive substitution. Second, deleterious mutations may interfere with the spread of an advantageous allele through a population, leading to altered patterns of linked neutral variation. The goal of the proposed research is to use computer simulations to investigate the conditions under which deleterious mutations significantly alter our ability to identify and estimate the frequency of adaptive evolution.