The work presented here was carried out in collaboration between all authors. EJF, NS and JC defined the research theme. EJF and NS designed methods and experiments, carried out the laboratory experiments, analyzed the data, interpreted the results and wrote the paper. PM and AG co-designed the dispersal and colonization experiments, and co-worked on associated data collection and their interpretation. JC co-designed experiments, discussed analyses, interpretation, and presentation. All authors have contributed to, seen and approved the manuscript.
We thank P. Doerder for very kindly donating strains, M. van Baalen for endorsing E.J.F.'s extended stay at Université Pierre et Marie Curie, and two anonymous reviewers for constructive comments. E.J.F. was supported by the European Research Training Network ModLife (Modern Life-History Theory and Its Application to the Management of Natural Resources), funded through the Human Potential Programme of the European Commission (Contract HPRN-CT-2000-00051). N.S. is a postdoctoral researcher of the Belgian Fund for Scientific Research (Chargé de Recherches F.R.S.-FNRS) and acknowledges a travel grant from the same institution (FRFC 2.4587.02F). P.M. was supported by a M.Sc. stipend from the Centre Regional des Oeuvres Universitaires et Scolaires de Paris. J.C. acknowledges support from Agence Nationale de Recherche (ANR-05-BLAN-0265-02).