Ellen Baake: Modelling and simulating Lenski’s long-term evolution experiment
Apr 29, 2019
10:00 - 11:00
Ellen Baake from Bielefeld University, Germany
For more information on the speaker, please visit https://www.techfak.uni-bielefeld.de/ags/bm/people/ellen.htm
We revisit the model by Wiser, Ribeck, and Lenski (Science 342 (2013), 1364–1367), which describes how the mean fitness increases over time due to beneficial mutations in Lenski’s long-term evolution experiment. We develop the model further both conceptually and mathematically.
we describe the experiment with the help of a Cannings model with
mutation and selection, where the latter includes diminishing returns
epistasis. The analysis sheds light on the growth dynamics within every
single day and reveals a runtime effect, that is, the shortening of the
daily growth period with increasing fitness; and it allows to clarify
the contribution of epistasis to the mean fitness curve. Mathematically,
we explain rigorous results in terms of a law of large numbers (in the
limit of infinite population size and for a certain asymptotic parameter
regime), and present approximations based on heuristics and supported
by simulations for finite populations.
This is joint work with Adrián González Casanova, Sebastian Probst, and Anton Wakolbinger.