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

9623881科彻：马拉维湖(东非)的慈鱼动物群代表了物种多样性的水平，在其他脊椎动物中是无与伦比的。马拉维湖估计有500种不同的物种，其中大部分只在这个湖里发现。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，导致物种丰富的力量至今仍在发挥作用。一种名为多米尼克假说的模型表明，极端的亲缘关系(大大减少了种群间的迁徙)和每个种群内独特的配偶识别系统的发展，导致了马拉维湖许多叶蝉物种的出现和维持。到目前为止，对这一假设的测试一直很难设计和实施。在这项研究中，杰弗里·马克特在托马斯·科彻的指导下，将使用详细的野外采样技术、实验室伴侣选择实验和分子标记来评估多米尼伊假说的地理和行为成分。DNA指纹图结合对南昆巴半岛马拉维斯湖东岸慈鱼种群的精细调查，将评估这些种群的嗜好程度；预测这些鱼几乎永远不会离开同源地。DNA指纹分析还将与实验室实验相结合，在实验室实验中，饲养在与自然条件紧密复制的围栏中的鱼，可以从多个种群中选择配偶；预测是，这些鱼将更喜欢自己种群的成员。这项研究的结果将检验多米尼克假说模拟马拉维湖慈嘴鱼物种多样性的能力。这将有助于评估多米尼克假说是否只适用于马拉维湖的鱼类物种多样性，或者是否可以更普遍地适用。

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.