Disease Ecology and its Role in Shaping Life History

摘要这项拟议的研究调查了疾病如何在亚利桑那州的蝾螈种群中出现，在种群中的个体之间传播，在一个地区的种群中传播，最后，通过自然选择，可能会改变蝾螈的生活史。 将检验三个假设。 在一个栖息地内，动物、土壤或水源是病毒的港湾，环境变化通过刺激病原体生长或削弱宿主蝾螈而引发感染。 另一种情况是，栖息地的蝾螈很容易感染疾病，疾病是从其他地方引入的。 实验和实地观察将评估蝾螈、无脊椎动物、牛、鸟类或人类作为疾病或传播病毒的载体的可能作用。 最后，疾病会选择不吃同类，这是蝾螈生活史上区域差异的原因。 病毒-媒介-虎蝾螈系统是疾病生态学中测试模型的理想选择。 亚利桑那州的人口进行了充分的研究，主要的病毒病原体是已知的，感染是频繁的，和一个濒危亚种的所有栖息地，疾病是常见的，可以取样。 在过去的15年里，一些两栖动物物种稳步下降，甚至灭绝，病原体是一个可能的原因。 这项研究将促进我们对病原体作为两栖动物减少的一个因素的理解;这是生物多样性普遍丧失的一个关键例子。 建议的实验和观察包括生态学、进化、病理学、病毒学和分子遗传学方面的专家。 垂直整合的田间和实验室实验将解开从分子遗传学到群体生物学的复杂相互作用，以测试疾病生态学的一般模型。

ABSTRACT The proposed research investigates how disease emerges in populations of salamanders in Arizona, is transmitted among individuals in populations, spreads across populations in a region, and finally, via natural selection, may alter salamander life history. Three hypotheses will be tested. Within a habitat, animals, soil, or water harbor viruses and environmental changes initiate infections by stimulating pathogen growth or weakening host salamanders. Alternatively, salamanders in a habitat are susceptible and disease is introduced from elsewhere. Experiments and field observations will evaluate the roles of salamanders, invertebrates, cows, birds, or humans as possible reservoirs of disease or vectors dispersing virus. Finally, disease selects against cannibalism, accounting for regional variation in salamander life history. The virus-vector-tiger salamander system is ideal for testing models in disease ecology. Arizona populations are well-studied, the principal viral pathogen is known, infections are frequent, and all habitats for one endangered subspecies where disease is common can be sampled. In the last fifteen years some species of amphibians have declined steadily, even to extinction, and pathogens are a possible cause. This research will advance our understanding of pathogens as a factor in amphibian declines; a key example of the general loss of biodiversity. Proposed experiments and observations incorporate experts in ecology, evolution, pathology, virology, and molecular genetics. Vertically-integrated field and laboratory experiments will untangle complex interactions from molecular genetics to population biology to test general models of disease ecology.