09:30 to 10:30 C Tarnita (Princeton University)Plenary Lecture 7: Mathematics of social behavior I will begin with a discussion and mathematical description of the two different types of social construction: staying together' and coming together' (or aggregation). Staying together means that individuals form larger units (complexes, groups) by not separating after reproduction (eg. ant colonies, most multicellular organisms), while coming together means that independent individuals form aggregates (eg. most animal groups, including humans). For each of these operations I will discuss its strengths and vulnerabilities in promoting social behavior, which will lead naturally into a discussion of the various mechanisms (and the relationships between them) that have been proposed to explain the evolution and maintenance of social behavior and cooperation: direct and indirect reciprocity, kin selection, group/multilevel selection, spatial structure, punishment/ostracism, rewards. I will discuss the theoretical frameworks in which these mechanisms are generally studied and for each mechanism I will present a simple model that captures the essence of how it can be described mathematically. Examples will be given from multicellularity, eusociality, bacterial biofilms, animal and human behavior. INI 1 10:30 to 10:45 S O'Brien (University of Exeter)Contributed Talk 7: Social evolution of toxic metal bioremediation in P.aeruginosa Bacteria are often iron-limited, hence produce extracellular iron-scavenging siderophores. A crucial feature of siderophore production is that it can be an altruistic behaviour (individually costly but benefitting neighbouring cells), thus siderophore producers can be invaded by non-producing social “cheats”. Recent studies have shown that siderophores can also bind other heavy metals (such as Cu and Zn), but in this case siderophore chelation actually reduces metal uptake by bacteria. These complexes reduce heavy metal toxicity, hence siderophore production may contribute to toxic metal bioremediation. Here, we show that siderophore production in the context of bioremediation is also an altruistic trait and can be exploited by cheating phenotypes in the opportunistic pathogen Pseudomonas aeruginosa. Specifically, we show that in toxic copper concentrations: 1) siderophore non-producers evolve de novo and reach high frequencies; and 2) that producing stra in s are fitter than isogenic non-producing strains in monoculture, and vice versa in co-culture. Moreover, we show that the evolutionary effect copper has on reducing siderophore production is greater than the reduction observed under iron-limited conditions. We discuss the relevance of these results to the evolution of siderophore production in natural communities and heavy metal bioremediation. INI 1 10:45 to 11:30 Morning Coffee 11:30 to 12:30 T Pfeiffer (Massey University)Plenary Lecture 8: Game theory for modelling microbial communities INI 1 12:30 to 13:30 Lunch at Wolfson Court 19:30 to 22:00 Conference Dinner at Emmanuel College