Evolutionary Ecology of Mycophagous Drosophila

果蝇在遗传学、发育和进化的研究中起着核心作用。Jaenike博士的研究主要集中在以蘑菇为食的果蝇物种上，这些物种非常适合研究这些昆虫的生态学和行为。拟议研究的一个主要问题将是这些果蝇和寄生于它们的一种线虫之间的生态相互作用。因为在任何时候都有多达50%的果蝇被寄生，而且因为被感染的果蝇在生育能力方面严重衰弱，这些线虫对果蝇种群有很大的影响。一系列的野外和实验室研究将用于研究线虫如何影响果蝇宿主的生存、交配成功和竞争相互作用。生态因素，如环境温度、蘑菇种类和果蝇种群密度，如何影响寄生虫的频率也将被检查。该研究将为宿主-寄生虫相互作用的生态学提供基础信息。此外，由于线虫有可能成为昆虫生物控制的重要媒介，这项工作可以为如何最好地实施这种控制计划提供启示。Jaenike博士还计划研究染色体，他已经发现染色体会影响果蝇的性别比例。因为“性别比”的男性只会产生女儿，理论上，这些染色体的出现频率会增加，最终导致种群灭绝。实际上，他们并没有这样做。Jaenike博士将研究可能阻止这些染色体扩散的生态因素，包括竞争能力和对线虫寄生的易感性。这项研究将深入了解一个层面（个体内的染色体）的选择如何被另一个层面（群体内的个体）的选择所抵消。

Drosophila have played a central role in the study of genetics, development, and evolution. Dr. Jaenike's research focuses on mushroom feeding species of Drosophila which are ideally suited to studies of the ecology and behavior of these insects. A primary concern of the proposed research will be with ecological interactions between these Drosophila and a species of nematode that parasitizes them. Because as many as 50% of these flies are parasitized at any time and because infected flies are seriously debilitated in terms of fertility, these nematodes have a substantial impact on populations of Drosophila. A series of field and laboratory studies will be used to investigate how nematodes affect survival, mating success, and competitive interactions of their Drosophila hosts. How ecological factors, such as ambient temperature, mushroom species, and Drosophila population densities, affect frequencies of parasites will also be examined. This research will provide basic information on the ecology of host-parasite interactions. In additions, because nematodes have the potential to be important agents for biological control of insects, this work could shed light on how best to carry out such control programs. Dr. Jaenike also has plans to study chromosomes which he has discovered to affect sex ratio in a species of Drosophila. Because "sex ratio" males sire only daughters, these chromosomes are expected in theory to increase in frequency and eventually cause population extinction. In reality, they do not do so. Dr. Jaenike will study ecological factors, including competitive ability and susceptibility to nematode parasitism, that may prevent the spread of these chromosomes. This research will provide insight on how selection at one level (chromosomes within individuals) is counteracted by selection at another level (individuals within populations).