The pinnacle of fish sociality: what can we learn?

What are the fundamental principles of social evolution? Biological theory can answer this question satisfactorily. But what about empirical tests of seminal hypotheses? Correlative data are rarely suffi­cient to critically test predictions derived from evolutionary concepts. It needs experiments with sys­tems that can be manipulated within the range of their natural ecological and social conditions. The co­operatively breeding cichlids of Lake Tanganyika provide such opportunity. They feature the most com­plex social organisation known among fishes, which does not fall short of highly organised societies found in birds and mammals, their ecology can be studied in every desired detail, and their environmen­tal and social conditions can be varied experimentally under controlled conditions. Even their behaviour can be experimentally manipulated to the researcher’s liking. In this talk I aim to show how these cich­lids can help us to understand the relative importance of different selection mechanisms generating adaptive social behaviour, and their interaction.