Collaborative Research: Developing novel methods for estimating coevolutionary processes using tapeworms and their shark and ray hosts

合作研究：开发利用绦虫及其鲨鱼和鳐鱼宿主估计共同进化过程的新方法

• 批准号: 1457762
• 负责人: Janine Caira
• 金额: $ 39.59万
• 依托单位: University of Connecticut
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-15 至 2020-02-29
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1457762&HistoricalAwards=false
• 关键词: Collaborative; Research; Developing; novel; methods

Parasites are everywhere and many species have been with their hosts for a long evolutionary time and are extremely particular about the kinds of hosts they parasitize. Somewhat unexpectedly, recent research suggests that many parasite species do not necessarily share a similar evolutionary history with their hosts; rather other factors may be at play in shaping these parasitic associations. Yet, little is understood about which other factors, such as diet or geographic distribution, influence these relationships. This is largely because a method for assessing the importance of other factors is not currently available. This research will develop a method and will test it using a well-known and species-rich system consisted of the tapeworms of sharks and stingrays. This method will be widely applicable to other coevolutionary systems, helping to further our understanding not only of host-parasite systems in general, but also of other biological systems involving intimate associations. Close species associations are ubiquitous and better knowledge on the role of the environment in shaping species associations will be critical to forecasting biodiversity's response to climate change. The research will train postdoctoral researchers and graduate students in quantitative techniques in evolutionary biology.This project moves towards a more mechanistic modeling of the biological influences involved in the coevolution between parasites and hosts. Phylogenies will be generated for a large number of cestode genera, time-calibrated phylogenies will be generated for their corresponding shark and ray (elasmobranch) hosts and robust parasite-host association data will be compiled. New methods and open-source software tools using approximate Bayesian computation will be developed to allow the estimation and testing of models for the evolution of parasite-host systems. The models for parasite evolution will be geographically explicit and will include factors such as cospeciation, environmentally driven extinction, geographic constraints on dispersal and host-switching, and some effects of intermediate hosts. These rich empirical data sets will allow the use of robust, cross-validation methods for hypothesis testing. The end result will be a methodological framework for assessing the contributions of multiple factors, in addition to cophylogeny, in structuring host associations and parasite evolution. The new software will be used to address three main research questions regarding factors that underlie parasite-host interactions including the relative roles various factors play in systems with different properties.

寄生虫无处不在，许多物种已经与宿主一起度过了很长的进化时间，并且对它们寄生的宿主种类极为挑剔。有点出乎意料的是，最近的研究表明，许多寄生虫物种不一定与其宿主具有相似的进化历史。相反，其他因素可能在形成这些寄生关联中发挥作用。然而，人们对哪些其他因素（例如饮食或地理分布）影响这些关系知之甚少。 这主要是因为目前还没有评估其他因素重要性的方法。这项研究将开发一种方法，并将使用由鲨鱼和黄貂鱼的绦虫组成的众所周知且物种丰富的系统对其进行测试。这种方法将广泛适用于其他共同进化系统，不仅有助于进一步了解一般的宿主-寄生虫系统，而且有助于进一步了解涉及密切关联的其他生物系统。密切的物种关联无处不在，更好地了解环境在形成物种关联中的作用对于预测生物多样性对气候变化的响应至关重要。该研究将为博士后研究人员和研究生提供进化生物学定量技术方面的培训。该项目致力于对寄生虫和宿主之间的共同进化所涉及的生物影响进行更加机械化的建模。将为大量绦虫属生成系统发育树，为其相应的鲨鱼和鳐鱼（软骨鱼类）宿主生成经过时间校准的系统发育树，并编译可靠的寄生虫-宿主关联数据。将开发使用近似贝叶斯计算的新方法和开源软件工具，以允许估计和测试寄生虫宿主系统进化的模型。寄生虫进化模型将在地理上是明确的，并将包括诸如共种、环境驱动的灭绝、传播和宿主转换的地理限制以及中间宿主的一些影响等因素。这些丰富的经验数据集将允许使用稳健的交叉验证方法进行假设检验。最终结果将是一个方法框架，用于评估除了共系统发育之外的多种因素在构建宿主关联和寄生虫进化方面的贡献。新软件将用于解决三个主要研究问题，这些问题涉及寄生虫与宿主相互作用的因素，包括各种因素在具有不同特性的系统中发挥的相对作用。