Chance and evolution in early life
Prof. Irene Chen, University of California, Santa Barbara
Evolution can be thought of as a random walk on the fitness function in the space of possible sequences. Using in vitro RNA evolution, we study these fitness ‘landscapes’ to understand the roles of natural selection and chance in determining evolutionary outcomes. Complete mapping of the fitness landscape for small RNAs gives quantitative insights into the probability of emergence of functional RNAs and the isolation of evolutionary solutions. In addition, we use the fitness information to infer chemical kinetic parameters of the RNA, including the underlying distribution of rate constants among random RNAs. I will also describe our experimental work on the influence of spatial structure on the spread of genes by horizontal transfer.