When mutant individuals with a changed trait are successful, they will increase in numbers and thus start affecting population dynamics, resource availability, the prevalence of parasites, the intensity of interspecific competition, community structure, and so on. Together, these effects will cause a feedback because ecological parameters will, in general, affect the traits that are favoured. More on this can be found in the introduction to my thesis (1994).
Such eco-evolutionary feedback loops will be particularly intense in systems with interacting populations: adaptation and counteradaptation often have population dynamical consequences. A good example is the evolution of virulence. If avirulent parasites are common, host density increases and, with it, the force of infection. But so does the intensity of within-host competition, which favours more virulent parasites. Ecological effects will modify or sometimes even revert selection pressure on virulence.
How spatial dynamics affect evolution (and vice versa) is still poorly understood. When a mutant invades a 'viscous' system it typically does so in the form of an expanding cluster of relatives. Ultimately it is therefore the characteristics of these clusters that determine whether the invasion will be successful. In other words, the unit of selection in a viscous systems is a cluster of relatives rather than the individual (which amounts to a re-discovery of Hamilton's kin selection principle). Correlation dynamics modeling provides new mathematical tools to study the effect of space on ecological interactions.
Traditionally, ecology recognizes three broad kinds of interactions among organisms: competitive interactions, exploiter-victim interactions (i.e., predators and prey, host and parasites) and mutualistic interactions. Upon closer scrutiny, however, interactions between individuals often appear to be mixtures. For example, certain parasites may, under certain conditions, benefit their hosts. Under what conditions does the common interest prevail over the private interests of the partners? If we understand better under what conditions (if ever) parasites will become full-blown mutualists, we obtain much-needed insight in many evolutionary transitions, ranging from the appearance of eucaryotes to the evolution of sociality.
When an organism communicates, it does so to increase its fitness. If it can gain from misleading the recipient, it will therefore give false information. The recipient of the signal is selected to judge the signal with respect to its 'credibility'. Recipients can enforce credibility by only 'believing' signals that are costly, so costly that senders cannot afford cheating. But sometimes sender and receiver do have a sufficient common interest, however, so that both benefit from the exchange of accurate information. But what will happen if sender and receiver have only partially overlapping interests?
Since Darwin and Hamilton it has become obviously clear that harmony in colonies of social insects is due to the relatedness of colony members. Why, then, do we sometimes observe queens that mate with multiple males or even unrelated queens that share a nest? Either of these processes diminishes relatedness and increases the potential for conflict. One of the hypotheses that has been proposed to explain this phenomenon is that heterogeneous colonies are more resistant to parasitism. This is an interesting hypothesis, but it is not at all immediately clear whether it works if it is taken into account that such heterogeneous colonies are likely to have more parasites able to infect them.
At a different level again, it has become clear that parasite evolution can be strongly affected by within-host competition among strains. What is not often realised (and certainly not in the simplest mathematical models) is that these interactions are often mediated by the immune system. Does within-host competition still lead to increased virulence or, as has been suggested recently, to reduced virulence instead?
A list of recent publications can be found here.
- PhD, University of Amsterdam
- Postdoc, University of Amsterdam
- Postdoc, University of Warwick (UK)
- Poste rouge, CNRS/Université Pierre et Marie Curie, Paris
- Fellowship, Royal Dutch Academy of Arts and Sciences/University of Amsterdam
- Chargé de Recherche, CNRS/Université Pierre et Marie Curie, Paris
- Head of the research unit UMR 7625 « Ecologie & Evolution »
- Chargé de Recherche, CNRS/Institut Biologie de l'Ecole Normale Supérieure, Paris
- Visitor at the IHÉS in Bures-sur-Yvette.
- Alexandre Suire (MSc)
- Evolution of information use
- Phuong Nguyen (MSc)
- Evolution in host-parasite systems
- Darja Dubravcic (with Clément Nizak, Paris)
- Evolution in Dictyostelium slime moulds
- Anaïs Bompard (with Thierry Spataro, Paris)
- Evolution of sex determination in Hymenopteran parasitoids
- William Lee (Thesis supervisor: Vincent Jansen, Royal Holloway College, London, Viva: October 2012)
- Adaptive dynamics of parasites and mutualists
- Sandrine Adiba (with Frantz Depaulis, 2010)
- Selection and drift in microbial ecosystems.
- Sébastien Ballesteros (Thesis supervisor: Bernard Cazelles, 2009. Now apparently setting up a Big Data Start-Up in New York.)
- Evolution of host-pathogen systems
- Sonia Kéfi (Utrecht University, Thesis supervisor Max Rietkerk,2008. Now CNRS researcher in Montpellier.)
- Bistability and desertification
- Sébastien Lion (PhD, co-directed with Régis Ferrière, October 2007. Now CNRS researcher in Montpellier.)
- Evolution of mutualism in spatially extended systems
- Mathieu Molet (PhD, Thesis supervisor: Christian Peeters, September 2007)
- Evolution of reproductive strategies in queenless ants
- Mathias Gauduchon (postdoc, Maître de Conférences in Marseille now.).
- Dynamics and evolution of fissioning ant colonies.
- Samuel Alizon (PhD: October 2006. Now CNRS researcher in Montpellier.)
- Evolution of virulence and within-host processes
- Carmen Bessa Gomes (Post-doc until 2004; now Maître de Conférences at University Paris XI).
- Allee effects and sexual selection
- Arnaud Pocheville (DEA: Sept. 2004. Went on to do a PhD, I think he is a researcher in Australia now.)
- Termite thermodynamics
- Sonia Kéfi (DEA: Sept. 2004.)
- Bistability and desertification: bifurcation analysis and evolutionary aspects
- Claire Cadet (PhD: February 2003)
- Adaptation to fluctuating environments
My PhD supervisor, colleague and friend Maurice W. Sabelis (University of Amsterdam) sadly passed away in January 2015.
Last update December 22, 2015 by Minus