Problems in Evolutionary Theory

群体遗传学的方法将应用于两个 物种的主要层次。 调查人员会集中精力 建立模型，可以导致现实的预测， 解释。 这项工作的一部分将比较 （存活和生育）由近亲繁殖产生的个体 与那些通过异交产生的适应性无关 个体 这样的比较可以估计“近亲繁殖” 抑郁症”，近交后代相对于 远交后代的适应性 近亲繁殖抑郁症是非常 在植物和动物育种中很重要， 在决定繁殖系统的进化方面。 近亲繁殖衰退的遗传原因并不完全 目前理解。 所以研究那些 异交和自花受精（如大多数植物 人口）应该有助于区分不同的 可能的机制。 为此，研究人员将研究一种 一种模型，其中许多遗传基因座影响适合度，因为基因座 易受突变的影响，对健康产生有害影响。 研究人员将预测 近交衰退和自花受精水平。 然后他们 将把这些理论结果与自然界的数据进行比较， 驯化的植物种群 研究新物种是如何形成的将使用模型， 种群随机地从一个平衡态转移到 另 由少数殖民者建立的人口将 被利用 这个过程可能对产生新物种很重要， 最近在“高峰”的名义下， 转移”。 很少有关于这一过程的遗传模型的研究 已经进行了，但这些研究必须在进行之前进行。 知道峰值偏移的可能性。

The methods of population genetics will be applied to two main levels of the species. The investigators will concentrate on making models that can lead to realistic predictions and explanations. One part of the work will compare the fitness (survival and fertility) of individuals produced by inbreeding with the fitness of those produced by outcrossing to unrelated individuals. Such comparisons allow estimates of "inbreeding depression", the fitness deficit of inbred progeny relative to the fitness of outbred progeny. Inbreeding depression is very important in plant and animal breeding, and may also be important in determining the evolution of breeding systems. The genetic causes of inbreeding depression are not fully understood at present. So studying populations which display both outcrossing and self-fertilization (as in most plant populations) should help to distinguish between the different possible mechanisms. To do this, the investigators will study a model in which many genetic loci affect fitness because the loci are subject to mutations having deleterious effects on fitness. The investigators will make predictions about the relationship of inbreeding depression and level of self-fertilization. Then they will compare these theoretical results with data from natural and domesticated plant populations. Studies of how new species are formed will use models in which population randomly shifts from one equilibrium state to another. Populations founded by a small number of colonists will be used. The process may be important in generating new species, and has been much discussed recently under the name of "peak shifting". Few studies of genetic models of the process have been carried out, but these studies must be done before it is known how likely peak shift is.