Systematics and Evolution of Body Size in Feather Lice (Phthiraptera: Columbicola)

羽虱（Phthiraptera：Columbicola）体型的系统学和进化

• 批准号: 0107947
• 负责人: Dale Clayton
• 金额: $ 24万
• 依托单位: University of Utah
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-01 至 2006-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0107947&HistoricalAwards=false
• 关键词: Systematics; Evolution; Body; Size; Feather

This project will explore co-speciation in a host-parasite system consisting of birds and their host-specific feather lice. Co-speciation takes place when parasite speciation (formation of new species) occurs in concert with host speciation. Repeated bouts of co-speciation result in host and parasite evolutionary trees that are mirror images of one another. The comparison of co-speciated evolutionary trees allows one to identify host-switching events, in which parasites "jump" from one ancestral host group to a new one. The bird-louse system provides a model in which it is possible to: 1) identify host-switching events by comparing evolutionary trees that have been reconstructed on the basis of DNA sequence data; and 2) determine under what conditions host switches are likely to occur. Specifically, are parasites more likely to "jump" between closely related species of hosts, or between species of hosts that are similar in body size or some other attribute? Host switching is an important evolutionary phenomenon with broad relevance to human health. For example, the HIV virus appears to have evolved as a result of a host switch from non-human primates to humans. Similarly, human malaria may have evolved from avian malaria. Birds and lice are a model system in which it is possible to uncover cases of host-switching (see above) in conjuntion with experimental simulations of switching that involve moving host-specific parasites among different species of hosts. Such experiments cannot be done with humans and must therefore be studied using animal model systems. This project has an important training component. A Ph.D. student will participate in all aspects of the work and several undergraduate research assistants will also receive training .

该项目将探索由鸟类及其宿主特异性羽毛虱组成的宿主-寄生虫系统中的共物种形成。当寄生虫物种形成（新物种的形成）与宿主物种形成同时发生时，就会发生共同物种形成。反复的共同物种形成导致宿主和寄生虫的进化树互为镜像。通过对共同物种进化树的比较，人们可以确定寄主转换事件，即寄生虫从一个祖先寄主群体“跳跃”到一个新的寄主群体。鸟虱系统提供了一个模型，它可以：1)通过比较基于DNA序列数据重建的进化树来识别宿主转换事件；2)确定在什么条件下可能发生主机切换。具体来说，寄生虫是更有可能在关系密切的宿主物种之间“跳跃”，还是在体型或其他特征相似的宿主物种之间“跳跃”？宿主转换是一种重要的进化现象，与人类健康有着广泛的关系。例如，艾滋病毒似乎是由于宿主从非人类灵长类动物转向人类而进化的。同样，人类疟疾可能是从禽疟疾进化而来的。鸟类和虱子是一个模型系统，其中有可能发现宿主切换的情况（见上文），并结合切换的实验模拟，其中涉及在不同种类的宿主之间移动宿主特异性寄生虫。这类实验不能在人类身上进行，因此必须使用动物模型系统进行研究。这个项目有一个重要的培训部分。一名博士生将参与所有方面的工作，几名本科生研究助理也将接受培训。