Lab-meeting: is there a physical limit to fitness?

Posted by Erik Svensson

I hope all ESEB-members have had a Happy Easter. I post somewhat late for the lab-meeting tomorrow, but we will start lightly with a short and fairly recent paper in Science from Rich Lenski's laboratory, which adresses a fundamental question in evolutionary biology: is there a limit to how much fitness can increase? You will find a link to the paper here, and the Abstract is posted below.

Time and place as usual:

Where: Seminar room "Argumentet", 2nd floor (Ecology Building)

When: Tuesday, April 7, 10.30

Long-Term Dynamics of Adaptation in Asexual Populations

Michael J. Wiser, Noah Ribeck & Richard E. Lenski

Experimental studies of evolution have increased greatly in number in recent years, stimulated by the growing power of genomic tools. However, organismal fitness remains the ultimate metric for interpreting these experiments, and the dynamics of fitness remain poorly understood over long time scales. Here, we examine fitness trajectories for 12 Escherichia coli populations during 50,000 generations. Mean fitness appears to increase without bound, consistent with a power law. We also derive this power-law relation theoretically by incorporating clonal interference and diminishing-returns epistasis into a dynamical model of changes in mean fitness over time.