Title

Beyond neutrality: Noise-induced evolutionary dynamics

Abstract

The forces of evolution are often decomposed into mutation, migration, genetic drift and natural selection. In this talk we’ll explore how the last two of these forces can become entwined; that is when genetic drift (demographic stochasticity) can itself generate selective pressures. Intriguingly, this can lead to counter intuitive results such as selection reversal, whereby a genotype predicted to be selected for deterministically in fact has a lower fixation probability than its competitor. To illustrate this effect I will begin using some well-established models based on simple Lotka-Volterra type dynamics [1,2]. I will then outline how the same effect can emerge in sex chromosome evolution, helping to explain observed empirical patterns [3]. Finally I’ll talk about ongoing work on simple models for the evolution of multicellularity that use a growth-fragmentation-coalescence process framework [4].

1. Constable, George WA, et al. "Demographic noise can reverse the direction of deterministic selection." Proceedings of the National Academy of Sciences 113.32 (2016)
2. Constable, George WA, and Alan J. McKane. "Exploiting fast-variables to understand population dynamics and evolution." Journal of Statistical Physics 172 (2018)
3. Veller, Carl, et al. "Drift-induced selection between male and female heterogamety." Genetics 207.2 (2017)
4. Tarnita, Corina E., Clifford H. Taubes, and Martin A. Nowak. "Evolutionary construction by staying together and coming together." Journal of Theoretical Biology 320 (2013)

If you wish to attend this seminar online, please send an email to s.banerjee2@uva.nl to receive the zoom-link.