EVOP Subgroup Contributed Talks

Anthia Le

The University of Queensland

"The Evolution of Menopause"

When we examine the life history of humans against our close primate relatives, the great apes, we see that human adult lifespans include a post-menopausal life stage. This led to the question, “how did human females evolve to have old-age infertility?”Morton et al. suggested that ancestral male mating choices, particularly forgoing mating with older females, was the driving force behind the evolution of menopause. As their agent-based model is difficult to analyse, we propose an analogous system of ordinary differential equations (ODE) to examine their conclusions. Our conclusions contradict that of Morton et al., as we find that even the slightest deviation from an exclusive mating preference for younger females would counteract the evolution of menopause.

Gabriela Lobinska

Weizmann Institute of Science

"Should you inherit your parent's mutaiton rate?"

Mutators (individuals with uncommonly high mutation rate) are subject to second-order selection on the mutations they acquire. Mutators can be selected for since they can attain adaptive genotypes faster than their non-mutator counterparts. However, when the population is well-adapted to its environment, most mutations will be deleterious and hence mutators will be selected against. A mutator phenotype can be due to mutations in mismatch repair genes and DNA polymerases, and hence be strongly inherited from parent to offspring. But, it can also be caused by stochastic factors, such as protein concentrations, and hence be only inherited for few generations. Recently, an epigenetic mechanism for generating variability in mutation rate within the population and between parent and offspring was observed (Uphoff et al. Science 2016). We wondered which level of mutation rate inheritance – high, due to genetic factors, intermediate, due to epigenetic factors, or random, due to stochastic factors - leads to fastest adaptation. Using a combination of stochastic simulations and mathematical modelling, we show that intermediate levels of mutation rate inheritance, corresponding to epigenetic inheritance, result in fastest adaptation over rugged landscapes. This is due to an association between mutator phenotypes and pre-existing mutations, which aids crossing fitness valleys.

Peter Harrington

University of Alberta

"A framework for studying transients in marine metapopulations"

Transient dynamics can often differ drastically from the asymptotic dynamics of systems. In this talk we provide a unifying framework for analysing transient dynamics in marinemetapopulations, from the choice of norms to the addition of stage structure. We use the $ell_1$ norm, because of its biological interpretation, to extend the transient metrics of reactivityand attenuation to marine metapopulations, and use examples to compare these metrics under the more commonly used $ell_2$ norm. We then connect the reactivity and attenuation of marine metapopulations to the source-sink distribution of habitat patches and demonstrate how to meaningfully measure reactivity when metapopulations are stage-structured.