RECOMBINANT DNA IN POPULATION GENETICS

进化是一个历史过程，历史对现在的影响很大- 日观察。 使用限制性酶切图谱或DNA的遗传调查 测序包含了大量的历史信息。 我们的总体目标是 提取这些历史信息， 关于进化遗传学中三个相互关联的问题的推论： 种群结构、创始者和瓶颈事件以及物种形成。 种群结构包括有效大小，交配系统， 基因流的模式。 我们的首要目标是发展系统发育 人口结构综合分析技术 分支系统学（一种传统上用于推断种间 结合理论（人口的分支学科 遗传学，处理当前遗传的谱系结构 变体）。 这些技术将应用于小龙虾，蚱蜢， 和蜥蜴 选择这些物种是因为地理， 行为和/或栖息地数据表明，这一群体涵盖了广泛的 限制基因流动在不同地理区域的可能性范围 鳞片 今天，一个物种的遗传变异的数量和分布取决于 根据其当前的人口结构和过去的历史（例如， 创始人/瓶颈事件）。 我们的第二个具体目标是发展 从当前种群中划分历史的系统发育方法 结构 我们将使用嵌套分支分析的地理 为了检测最近的历史事件，使用 无根进化树的分支长度分布 单倍型，以检测更古老的历史事件，并使用最近演变的 单倍型，以限制推理后事件的基因流模式。 测试 这些方法，我们将应用这些技术对几种生物， 我们有很好的证据证明过去的历史事件（无论是栖息地 在已知的时间尺度上， 应涵盖广泛的预测容易检测的历史 事件 这些物种还包括小龙虾、蚱蜢和 蜥蜴，并广泛重叠的生物体用于我们的第一个具体的 尽管地理尺度不同，但目标不同。 我们还将测试 我们的假设的有效性，通过研究已知经历过 最近的创始人事件;如人为释放的人口 奥扎克和各种圈养动物园种群中的有颈蜥蜴。 DNA中编码的历史信息超越了存在 物种本身，因此密切相关的物种的遗传可以 从基因数据中构建。 我们将建立这样一个新的历史， 一种种类繁多的小龙虾亚属， 遗传学是为了检验关于种群结构之间相互作用的假设， 历史事件，适应性变化，表型变化，地理 隔离和物种形成。

Evolution is an historical process, and history greatly influences present- day observations. Genetic surveys using restriction mapping or DNA sequencing contain much historical information. Our general aim is to extract this historical information and use it in making evolutionary inferences on three interrelated problems in evolutionary genetics: population structure, founder and bottleneck events, and speciation. Population structure encompasses effective size, system of mating, and pattern of gene flow. Our first and primary aim is to develop phylogenetic techniques for the analysis of population structure by integrating cladistics (a methodology traditionally used to infer interspecific phylogenies) with coalescent theory (the subdiscipline of population genetics that deals with the genealogical structure of current genetic variants). These techniques will be applied to crayfishes, grasshoppers, and lizards. These species were chosen because biogeographical, behavioral, and/or habitat data indicate that this group covers a broad range of potential for restriction of gene flow on various geographical scales. The amount and distribution of genetic variation in a species today depends both upon its current population structure and upon past history (e.g., founder/bottleneck events). Our second specific aim is to develop phylogenetic methods of partitioning history from current population structure. We will use a nested cladistic analysis of geographical associations among haplotypes to detect recent historical events, use the branch length distribution of the cladogram (unrooted evolutionary tree) of the haplotypes to detect older historical events, and use recently evolved haplotypes to restrict inference to post-event gene flow patterns. To test these approaches, we will apply the techniques to several organisms for which we have excellent evidence of past historical events (either habitat fragmentation or colonization of new areas) on a known time scale that should cover a broad range in the predicted ease of detection of historical events. These species will also include crayfishes, grasshoppers and lizards, and broadly overlap with the organisms used for our first specific aim although the biogeographical scale differs. We will also test the validity of our assumptions by studying populations known to have undergone recent founder events; such as artificially released populations of collared lizards in the Ozarks and various captive zoo populations. The historical information encoded in the DNA extends beyond the existence of the species itself, and hence phylogenies of closely related species can be constructed from genetic data. We will construct such a phylogeny for a speciose and very diverse subgenus of crayfish and use the resulting phylogeny to test hypotheses about interactions among population structure, historical events, adaptative change, phenotypic change, geographical isolation, and speciation.