Title: Incorporating Human Contact Structure Into Avian Influenza Spillover ModelsAbstract: Spillover risk of zoonotic diseases typically focuses on just the first successful spillover event to humans, assuming that the probability of this first infection creating an outbreak in a human population is constant across different populations. However, for a single human infection to become an outbreak, it must overcome stochastic extinction and control measures. Thus, outbreak probabilities in human populations depend greatly on contact structure and human density, factors which vary greatly by location. With a simple network model including both livestock and humans and simulating initial spillover events and subsequent outbreaks in humans, we explore how these factors combine to produce a more holistic metric of spillover risk.
 

Title: Eco-evolutionary games in noisy environments

Abstract:
Cooperative and competitive interactions between individuals are often linked to the use of environmental resources: management of fisheries, availability of nutrients, pollution, elimination of pathogens… Organisms are altering their environment according to different strategies, and in turn the state of the environment influences the payoff matrix of social interactions in a population. The recent field of eco-evolutionary game theory studies these eco-environmental feedbacks and their impact on the evolution of cooperation in a population. Previous papers assume an intrinsic dynamics of the environment that is deterministic, although it’s known that noise in payoffs can have a qualitative impact on social behaviors. In my talk, I will present how we included a stochastic dynamics of the environment in the eco-evolutionary game theory framework. Focusing on a low dynamics of the environment compared to the dynamics of evolution of strategies, we demonstrated mathematically that the resulting social behavior is often a mixture game types played at the different levels of environmental resources: the population is constantly adapting to the environment. However, noise of the environment can also make mixed equilibrium of cooperators and defectors stable, or prevent situations of bistability. When the dynamics of the environment accelerates, the population has less time to adapt. Simulations show that as a consequence, the social behaviors are closer to the ones without noise. If the changes of the environment are both fast and very noisy, the individuals tend to decrease alternation between equilibria and stay at the behavior which is more often optimal. These results extend the ones obtained in a det