Richard E. Lenski

John A. Hannah Distinguished Professor

Ph.D., University of North Carolina, 1982

2209 Biomedical and Physical Sciences Building
Office Telephone: 517-884-5397
Research website

Ecology, Genetics, Evolutionary Biology

I am interested in the ecological processes and genetic mechanisms that cause evolutionary change. I study microorganisms in order to take advantage of their rapid generations and large populations, which make it feasible to test evolutionary hypotheses by direct experimentation.

In one project that has been on-going for more than 20 years, my students and I are studying the adaptation and divergence of bacterial populations, while they evolve in a defined laboratory environment for more than 45,000 generations. We seek to understand the dynamics of these evolutionary processes as well as the ecological, physiological, and genomic changes that are responsible for the substantial gains in fitness that we observe.

In other projects, we use bacteria and the viruses that infect them as model systems for studying the ecology and evolution of host-parasite interactions. Yet other projects are concerned with the spread of antibiotic resistance, the evolution of mutation rates, the form and extent of interactions among mutations, life in variable environments, and costs and benefits of primitive sociality in bacteria.

I also collaborate with computer scientists, especially Charles Ofria (, on the evolution of artificial life, in the form of self-replicating computer programs that mutate at random, compete for resources, and thereby adapt by natural selection to the computational worlds in which they live.

Representative Publications

Yedid, G., C.A. Ofria, and R.E. Lenski. 2009. Selective press extinctions, but not random pulse extinctions, cause delayed ecological recovery in communities of digital organisms. American Naturalist 173: E139-E154.

Rozen, D.E., N. Philippe, J.A. de Visser, R.E. Lenski, and D. Schneider. 2009. Death and cannibalism in a seasonal environment facilitate bacterial coexistence. Ecology Letters 12: 34-44.

Hillesland, K.L., G.J. Velicer, and R.E. Lenski. 2009. Experimental evolution of a microbial predator's ability to find prey. Proceedings of the Royal Society, London B 276: 459-467.

Clune, J., D. Misevic, C. Ofria, R.E. Lenski, S.F. Elena, and R. Sanjuan. 2008. Natural selection fails to optimize mutation rates for long-term adaption on rugged fitness landscapes. PLoS Computational Biology 4: e1000187.

Blount, Z.D., C.Z. Borland, and R.E. Lenski. 2008. Historical contingency and the evolution of a key innovation in an experimental population of Escherichia coli. Proceedings of the National Academy of Sciences, USA 105: 7899-7906.

Cooper, T.F., S.K. Remold, R.E. Lenski, and D. Schneider. 2008. Expression profiles reveal parallel evolution of epistatic interactions involving the CRP regulon in Escherichia coli. PLoS Genetics 4: e35.