Collaborative Research: Speciation in laboratory populations of bacteriophage T7

这项研究将增进我们对种群内发生的进化变化(微观进化)如何推动种群之间繁殖的遗传障碍的积累，最终导致新物种的起源(宏观进化)的理解。虽然众所周知，不同种群所经历的环境差异会导致不同的适应，这些不同的适应在不同亲本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可以发生同样的情况。这项研究的目的是开发数学模型来预测在相同环境中进化的种群之间不相容的适应积累的速度，并使用实验室进化实验来检验预测。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，该合作利用计算和实验室进化实验相结合的方式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围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、微生物学和进化论的基本概念，然后团队将以英语和西班牙语教授这些社区的教室和科学博览会。我们的目标是让学生在这个推广项目的过程中成为教师。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，从最初不相容的适应的积累开始。中心目标将是从实验上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，这些突变会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被用来开发定量预测，然后使用实验室进化实验进行测试。研究人员将：1)监测在相同的实验室环境中进化的噬菌体T7的复制种群的进化；2)在这些进化的种群对之间产生杂交后代，并监测突变的积累，这些突变增加了亲本种群中的适应度，但降低了杂交后代的适应度；3)测量这种不相容适应的累积速度，以及4)确定已识别的不相容适应是否源于研究人员的数学模型预测的可能的功能相互作用的类型。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势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.