Collaborative Research: Speciation in laboratory populations of bacteriophage T7

这项研究将促进我们对种群内发生的进化变化（微进化）如何驱动种群间繁殖遗传障碍的积累，最终导致新物种的起源（宏观进化）的理解。虽然已经确定，不同种群所经历的环境差异会导致不同的适应，而这些适应在不同父母的杂交后代中是不相容的，但只有少数进化实验表明，在相同环境中进化的种群中也会发生同样的情况。这项研究的目的是建立数学模型，以预测在相同环境中进化的种群之间不相容适应性积累的速度，并通过实验室进化实验来验证这些预测。该项目将建立在研究人员（Burch和Azevedo）之间长达14年的合作基础上，他们结合了计算和实验室进化实验来研究基因之间相互作用的原因和后果。此外，该项目将利用研究人员已经与教堂山和休斯顿及其周边地区的拉丁裔组织和双语小学建立的联系，建立主要由拉丁裔学生组成的团队。研究人员将指导学生团队开发游戏和活动，教授编码、数学建模、微生物学和进化等基本概念，然后这些团队将用英语和西班牙语向这些社区的教室和科学展览提供这些概念。我们的目标是让学生在这个拓展项目的过程中成为老师。该项目将使用计算和实验室进化实验来研究物种形成的初始阶段，从最初的不相容适应的积累。中心目标将是通过实验确定，适应是否经常导致功能上相互作用的突变的积累，随着时间的推移，这些突变使不同的种群难以产生可行的杂交后代。计算机模拟和数学模型将用于开发定量预测，然后将使用实验室进化实验进行测试。研究人员将：1)在相同的实验室环境中监测噬菌体T7复制种群的进化；2)在这些进化种群之间产生杂交后代，并监测突变的积累，这些突变增加了亲本种群中的一个种群的适应性，但降低了杂交后代的适应性；3)测量这种不相容适应积累的速度；4)确定已确定的不相容适应是否来自研究人员的数学模型预测的可能的各种功能相互作用。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This research will advance our understanding of how evolutionary changes happening within populations (microevolution) drive the accumulation of genetic barriers to reproduction between populations, eventually resulting in the origin of new species (macroevolution). Although it is well established that differences in the environment experienced by diverging populations can result in different adaptations that are not compatible in the hybrid offspring of divergent parents, only a few evolution experiments have shown that the same can happen in populations evolving in identical environments. The aim of this research is to develop mathematical models for predicting the rate at which incompatible adaptations accumulate between populations evolving in identical environments, and to test the predictions using laboratory evolution experiments. The project will build on a 14-year collaboration between the researchers (Burch and Azevedo) that has used a combination of computational and laboratory evolution experiments to investigate the causes and consequences of interactions between genes. In addition, the project will capitalize on the connections that the researchers have already formed with Latino organizations and dual-language primary schools in and around Chapel Hill and Houston to build teams of primarily Latino students. The researchers will mentor the student teams to develop games and activities to teach basic concepts in coding, mathematical modeling, microbiology, and evolution, that the teams will then deliver, in English and Spanish, to classrooms and science expos in these communities. The goal is for the students to become teachers over the course of this outreach project.The project will use computational and laboratory evolution experiments to investigate the initial stages of speciation, from the accumulation of the very first incompatible adaptations. The central goals will be to determine, experimentally, whether adaptation often results in the accumulation of functionally interacting mutations that, over time, make it difficult for diverging populations to produce viable hybrid offspring. Computer simulations and mathematical models will be used to develop quantitative predictions that will then be tested using laboratory evolution experiments. The researchers will: 1) monitor the evolution of replicate populations of the bacteriophage T7 evolving in identical laboratory environments; 2) generate hybrid offspring between pairs of these evolving populations and monitor the accumulation of mutations that increase fitness in one of the parental populations, but decrease fitness in their hybrid offspring, 3) measure the rate at which such incompatible adaptations accumulate, and 4) determine whether the identified incompatible adaptations resulted from the kinds of functional interactions that the researchers’ mathematical models predict to be likely.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.