Sociality: genomes, behaviour & theory
Social evolution provides the unifying framework to study life. The same broad principles of cooperation, conflict and division of labour apply to insect societies, multicellular life, genome evolution and mutualistic symbioses alike. We study social evolution under three topics: social genomics of ants, communication and social behavior in ants, and theoretical and empirical work on the major transitions in evolution.
Social genomics of ants
Plasticity and division of labour are the keys to a functioning society. As ant societies consist of largely genetically similar individuals, regulation of gene expression is key to variable social phenotypes. We use genomic and transcriptomic tools to study the genomic underpinnings of social phenotypes, such as caste differentiation among queens and workers, queen fertility signaling, immune defences and variation in queen number among nests. This work entails comparative approaches within the genus Formica and across the phylogeny of ants, experimental approaches on common boreal ant groups such as Lasius and Formica, and population genomic studies of the invasive argentine ant Linepithema humile.
Participants: Heikki Helanterä, Jonna Kulmuni, Claire Morandin, Kishor Dhaygude
Collaborators: Sasha Mikheyev / Okinawa Institute of Science and Technology, Luke Holman / Univ. Melbourne, Michel Chapuisat / Univ. Lausanne, Jessica Purcell and Alan Brelsford / UC Riverside, Lumi Viljakainen / Univ. Oulu, Jes S. Pedersen / Univ. Copenhagen
Social behavior of ants
Even if ant colonies seem harmonious, they evolve in a complex balance of cooperation and conflict. According to inclusive fitness logic, the level of conflict is generally predicted to be the higher, the lower the relatedness among colony members is. Thus,Formicaants where variation in queen numbers within and among species creates a range of relatedness values from full sibs to practically zero are an ideal test bed for hypotheses on social conflicts. We study conflicts related to e.g. dispersal of young queens and males, brood cannibalism, and larval begging behaviours. These studies combine methods from behavior, physiology, population genetics, evolutionary theory and chemical ecology.
Participants: Heikki Helanterä, Sanja Hakala, Perttu Seppä, Rosanna Lindgren, Mélissa Peignier
Collaborators: Eva Schultner / Univ. Regensburg
Major transitions in evolution
The idea of comparing insect societies to multicellular organisms, with queens as the germline and workers as the soma, has a long history. In current social evolution theory, both evolution of “superorganismal” insect societies and evolution of multicellularity are examples of a major transition in evolution, where groups of lower level individuals have evolved into higher level individuals. I study the transition from solitary to social insects in a theoretical and empirical light. This includes mathematical models of the early stages of eusocial evolution and the role of haplodiplody, models and empirical tests where superorganismal societies are explicitly compared to multicellular animals, and philosophical and conceptual analyses of causality in evolutionary transitions.
Participants: Heikki Helanterä
Collaborators: Tobias Uller / Univ. Lund, Jussi Lehtonen / Univ. Sydney, Tuomas K. Pernu / King’s College London, Petri Rautiala / Univ. St. Andrews, Mikael Puurtinen / Univ. Jyväskylä, Patrick Kennedy / Univ. Bristol