Dissertation Research: Mechanics of Speciation in the Rock Dwelling Cichlid Genus Melanochromis in Lake Malawi, Africa (Teleostei:Cichlidae)

9623881 KOCHER马拉维湖（东非）的慈鲷鱼（双鱼：慈鲷科）的动物群代表了其他脊椎动物谱系中无与伦比的物种多样性水平。 马拉维湖估计有500种不同的物种，其中大部分只在这个湖中发现。 据认为，这种高水平的生物多样性是在马拉维湖存在的相对较短的时间内产生的。 许多研究人员认为，造成这种物种丰富度的力量今天仍然在发挥作用。 一个模型，多米尼克假说，表明极端philopatry（大大减少人口之间的迁移）和发展不同的配偶识别系统在每个人口，导致了许多马拉维湖慈鲷物种的出现和维护。 到目前为止，这一假设的测试一直难以设计和实施。 在这项研究中，杰弗里·马克特在托马斯·科赫尔的指导下，将使用详细的实地采样技术、实验室择偶实验和分子标记来评估多米尼假说的地理和行为组成部分。 DNA指纹分析，结合细尺度调查慈鲷种群沿着东海岸的马拉威湖Nanjumba半岛，将评估在这些人群的philopatry的程度，预测是，这些鱼几乎从来没有离开家。 DNA指纹分析也将与实验室实验相结合，在实验中，在接近自然条件的围栏中饲养的鱼被允许从多个种群中选择配偶;预测是鱼会更喜欢自己种群的成员。 本研究的结果将测试的能力Dominey假说模型的物种多样性在马拉维湖慈鲷鱼。 它将有助于评估是否Dominey假说只适用于马拉维湖慈鲷鱼的物种多样性或可以更普遍地应用。

9623881 KOCHER The fauna of cichlid fish (Pisces: Cichlidae) in Lake Malawi (eastern Africa) represent a level of species diversity unparalleled in other vertebrate lineages. Lake Malawi contains an estimated 500 distinct species, most of which are found only in this lake. It is thought that this high level of biodiversity has been generated during the relatively short time that Lake Malawi has been in existence. Many researchers believe that the forces responsible for generating this species richness are still operating today. One model, the Dominey hypothesis, suggests that extreme philopatry (greatly reduced migration between populations) and the development of distinct mate recognition systems within each population, have resulted in the emergence and maintenance of the many Lake Malawi cichlid species. Until now, tests of this hypothesis have been difficult to design and implement. In this study, Jeffrey Markert, under the direction of Thomas Kocher, will use detailed field sampling techniques, laboratory mate-choice experiments, and molecular markers to evaluate the geographic and behavioral components of the Dominey hypothesis. DNA fingerprinting, combined with a fine scale survey of cichlid populations along the eastern shore of Lake MalawiOs Nankumba Peninsula, will assess the extent of philopatry in these populations; the prediction is that these fish hardly ever Oleave homeO. DNA fingerprinting will also be combined with laboratory experiments in which fish, raised in an enclosure that closely replicates natural conditions, are permitted to choose mates from multiple populations; the prediction is that the fish will prefer members of their own population. The results of this study will test the ability of the Dominey hypothesis to model species diversity in Lake Malawi cichlid fish. It will help assess whether the Dominey hypothesis applies only to species diversity in Lake Malawi cichlid fish or can be applied more generally.