Theory of Adaptation in Experimental and Natural Populations

University Of Rochester, Rochester NY

Investigators

Abstract

The PI and co-PI propose to study how mutations that are beneficial to a species appear in and spread through experimental and natural populations. First, they will consider large populations of microbes in which several beneficial mutations compete with each other to increase in frequency (a process known as "clonal interference"). Mathematical theory will be developed to analyze how this clonal interference affects the speed and pattern of adaptation. Second, the PI and co-PI will study how the past spread of beneficial mutations can be inferred from present-day samples of DNA sequences from plants and animals. Mathematical models will be developed to estimate the frequency and strength of past beneficial mutations from DNA sequence data. This study will significantly improve our understanding of adaptation, one of the most important- but least understood genetically- of biological processes. In particular, the population genetic models developed in this work will facilitate rigorous experimental studies of the genetic basis of adaptation in microbes as well as in plants and animals. This work will have particular relevance to attempts to understand adaptation in large microbial species, e.g., the evolution of antibiotic resistance