Speaker
Description
Ageing’s sensitivity to natural selection has long been discussed because of its apparent negative effect on an individual’s fitness. Thanks to the recently described (Smurf) 2-phase model of ageing (data of Michael Rera) we propose a fresh angle for modeling the evolution of ageing. Indeed, by coupling a dramatic loss of fertility with a high-risk of impending death—amongst other multiple so-called hallmarks of ageing—the Smurf phenotype allowed us to consider ageing as a couple of sharp transitions. The birth–death model we describe here is a simple life-history trait model where each asexual and haploid individual is described by its fertility period xb and survival period xd .We show that xb and xd converge during evolution to configurations $x_b − x_d$ ≈ constant in finite time. To do so, we built an individual-based stochastic model which describes the age and trait distribution dynamics of such a finite population.Then we rigorously derive the adaptive dynamics models, which describe the trait dynamics at the evolutionary time-scale. We extend the Trait Substitution Sequence with age structure and study the limiting behaviour of this jump process when mutations are small. We show that the limiting behaviour is described by a differential equation for $(x_b,x_d)$. It’s a joint work with Michael Réra and Tristan Roget.
