Human Diversity seminar 8.11.2023, Avila

We are pleased to announce our next Human Diversity seminar with a talk from Piret Avila who is visiting us from Institute for Advanced Study in Toulouse (IAST), University of Toulouse.  You are welcome to joint seminar live at the campus in room A116 (Arcanum) or on zoom. Please send an email to humandiversity@utu.fi to gain the passcode for the zoom. Use your full name when attending the seminar via zoom.

11-12 PhD Piret Avila
Institute for Advanced Study in Toulouse (IAST), University of Toulouse

“The Expensive Germline and the Disposable Soma: exploring the co-evolution of life history and deleterious mutation rate”

Abstract: The cost of germline maintenance and repair gives rise to a trade-off between immutability (lowering deleterious mutation rates) and life-history functions. Life-histories and the mutation rate therefore co-evolve, but this joint evolutionary process is not well understood. I present a mathematical model to analyse the long-term evolution of traits affecting life-histories and deleterious mutation rate. I show that evolutionary stable life-histories and mutation rates can be  characterised using the basic reproductive number of the least-loaded class (expected lifetime production of  offspring without deleterious mutations born to individuals with the smallest number of deleterious mutations). We further analyse two specific biological scenarios: (i) co-evolution between reproductive effort and mutation rate and (ii) co-evolution between age at maturity and mutation rate. These two scenarios suggest two results. First, the trade-off between immutability vs life-history functions depends strongly on environmental conditions and baseline mutation rate. For example, low external mortality and high radiation environment favour high investment into immutability. Second, the trade-offs between different life-history factors can be strongly affected by mutation rate co-evolution and higher baseline mutation rates  select for “faster life histories”: (i) higher investment into fecundity at the expense of survival and (ii) earlier age of maturation at smaller sizes. I will also discuss the implications of this model on understanding evolution of ageing and I will give an overview of my future research agenda concerning the evolution of ageing.