OVERVIEW
We are interested in a number of questions at the intersection of evolution, cell biology and ecology. Our approach combines high-throughput experimental evolution in yeast with genetic engineering, genome sequencing, analytical theory and computer simulations.
Below are descriptions of a few of the projects we're currently working on. If you are a prospective grad student or postdoc, or an undergrad looking for research experience, please contact us to see about openings in the lab!
Below are descriptions of a few of the projects we're currently working on. If you are a prospective grad student or postdoc, or an undergrad looking for research experience, please contact us to see about openings in the lab!
Our Robot Overloards
Our programmable liquid-handling robot and Flow Cytometer with High-Throughput Sampler allow us to easily run large-scale, high-throughput experiments. Whether we are running long-term evolution experiments or short-term experiments measuring population/community dynamics, we can run thousands of yeast populations/communities/ecosystems simultaneously. We also use the robot to construct experimental metapopulations and metacommunities where we control the rate and pattern of dispersal between habitat patches.
Evolution of Ecological Communities
Explaining how the number, abundance and identity of species varies among ecological communities in space and time is a central question unifying ecology and evolution. We are using a series of engineered yeast metacommunities to ask questions about how ecological and evolutionary forces interact to structure ecological communities. Some of the questions that we are asking include: what are the relative roles of stochastic vs. deterministic processes in structuring ecological communities; are ecologically stable communities evolutionarily stable; can evolution cause species extinction; how does productivity and disturbance influence community evolution; what feedbacks exist between ecological and evolutionary dynamics; and what is the genetic and physiological basis of adaptation within species, and how do these genomic changes correspond to changes in community structure?
The Evolution of Cooperation and Conflict
Cooperation is responsible for generating organismal complexity and in creating numerous phenotypes of medical and ecological importance. Unicellular microbes commonly cooperate by producing diffusible public goods, which often correlate with virulence phenotypes and the ability to invade specific resource niches. Cooperation is unusually sensitive to ecological feedbacks. More interestingly, our previous work has shown that cooperation is inherently "niche-constructing", meaning that cooperative phenotypes alter their selective environment in a way that creates eco-evolutionary feedback. We are using yeast as an experimental model for investigating how various forms of eco-evolutionary feedback, including niche-construction, influence patterns of genetic and phenotypic diversity in microbial cooperator/cheater systems.
Spatial Evolutionary Ecology
Organisms in nature are heterogeneously distributed in space. Species and ecological communities often occur in a spatial patchwork of local sub-populations or communities that are connected via dispersal to form "metapopulations" and "metacommunities." Understanding how spatial population structure influences the ecology and evolution of species and communities is a central question in ecology and evolution. Using our liquid handling robot, we are conducting experiments of populations and communities under various modes of dispersal in order to investigate how metapopulation and metacommunity structure influence the distribution and abundance of individuals and species over ecological and evolutionary timescales.
Sex and the Fate of Adaptive Radiations
Our theoretical work suggests that sex can greatly alter the evolution of ecological communities. Eco-evolutionary feedbacks that dominate the community-level dynamics of asexual species are ameliorated or absent when closely related, but ecologically diverged, species can interbreed. We are using our yeast system to test these predictions and to examine how genetic and ecological forces can interact to alter the outcome of adaptive divergence and community evolution.