Dissertation Research: Imaginal Disc Development, Morphological Integration and Phylogenetic Pattern in Diopsid Dipterans

本研究计划的主要目标是研究飞蝇属的物种遗传结构与形态进化模式之间的关系。这些苍蝇是不同的，因为它们的头非常伸长，变成了长长的眼柄。这种奇怪的形态转变可能导致其他形态特征的变化，这是性状之间共享遗传效应的结果。因为任何给定的基因都可能影响许多不同的形态特征，选择改变生物体的一个部分可能会对身体的其他部分产生一连串的影响。目前，还不清楚身体各部分之间的这种基因联系在多大程度上指导了进化过程，因为这种联系可能会随着时间的推移而中断。回答这个问题的第一步需要比较不同物种之间的遗传联系类型。如果不同的物种表现出相似的遗传结构（即两个物种的不同身体部位以相同的方式遗传联系在一起），这可能会深刻地影响进化进程。这项研究将在两种不同种类的柄眼蝇中检验这种可能性。此外，性状之间共享遗传效应的模式将与这些果蝇的形态进化模式进行比较，以确定物种之间保持固定的遗传联系是否限制了这些物种的分化。

9423436 WAGNER The primary goal of this research program is to examine the relationship between the genetic structure of species and the pattern of morphological evolution within the fly genus Diasemopsis. These flies are distinct because of the extreme elongation of the head into long eye-stalks. This bizarre morphological transformation may have led to changes in other morphological traits as a result of shared genetic effects between traits. Because any given gene may influence a number of different morphological traits, selection to change one part of an organism may have a cascade of effects on other body parts. Presently, it is unknown how much this genetic connection between body parts directs the course of evolution since it is possible this connection can be broken over time. The first step toward answering this question requires comparing the types of genetic connections between different species. If different species show similar genetic structure (i.e. different body parts are linked genetically in the same manner in both species), this could profoundly influence the course of evolution. This research will examine this possibility in two different species of stalk-eyed flies. In addition, the pattern of shared genetic effects between traits will be compared with the pattern of morphological evolution within these flies to determine if those genetic connections which have remained fixed between species have constrained the divergence of these species.