I am a postdoc in the Desai Lab at the Department of Organismic and Evolutionary Biology at Harvard University. I am trying to uncover regularities in how microorganisms adapt to their environment and understand how these regularities emerge from the biology of the cell.
I use experiments in budding yeast, theory, and data from natural populations to address the following questions:
I am currently working on two main projects.
Microbes rapidly adapt to their environment, allowing them to escape the immune system, resist drugs, and undermine performance of synthetically engineered circuits. Predicting evolutionary trajectories is therefore a major problem in biology, with wide-ranging practical implications. Several recent studies (e.g., Burch and Chao 2000, Blount et al 2008, Bloom et al 2010, Woods et al 2011, Hayden et al 2011) have shown that epistatic interactions among mutations (i.e., when the effect of a mutation depends on the presence of other mutations in the genome) dramatically affect the course of adaptation implying that evolution may be essentially unpredictable. On the other hand, evolutionary outcomes may be statistically predictable if mutations leading to extreme and irregular changes in adaptability (also called evolvability) are rare, while mutations leading to small and regular changes in adaptability are common. We directly tested this hypothesis by measuring the variation in adaptability between related genotypes in laboratory yeast populations.
The paper is now in review and is available here. This is work with Dan Rice, Elizabeth Jerison, and Michael Desai.
This is a figure from the classic paper by Daniel Dykhuizen, Tony Dean and Dan Hartl called "Metabolic flux and fitness" (link). In this paper, which I highly recommend, the authors laid the foundation for understanding microbial fitness from biochemical principles. Building on their ideas, I am developing a theory for describing the effects of mutations and their interactions (epistasis) in terms of our current understanding of metabolism.