Division of Labour and the Evolution of Complexity

Division of labour is fundamental to the evolution of life on earth, allowing genes to work together to form genomes, cells to build organisms, pathogens to escape immune attack, and eusocial insect societies to achieve ecological dominance. Consequently, if we want to understand how life on earth evolved, we need to understand why division of labour does or, just as importantly, does not evolve. There are two major outstanding problems for our understanding of division of labour: First, how can we explain why division of labour has evolved with some traits, in some species, but not others? Given the potential benefits of dividing labour, why does it not arise more frequently in cooperative species? Second, in cases where division of labour has evolved, how can we explain the form that it takes? Why do factors such as the degree of specialisation, or mechanism used to produce different phenotypes, vary across species? I will combine my social evolution expertise with novel synthetic and genomic approaches to address these problems. I will explain the distribution and form of division of labour in the natural world, with an interdisciplinary research programme, divided into four work packages: (1) I will provide the first experimental test of the fundamental assumption that division of labour provides an efficiency benefit, by synthetically manipulating bacteria. (2) I will test how selection has acted for and against the evolution of division of labour in natural populations of bacteria, using novel genomic analysis techniques. (3) I will determine why division of labour evolved in some species, but not others, with an across species study on insects, and experimental evolution of bacteria. (4) I will establish a new field of research on why different species use different mechanisms to divide labour: genetic differences, environmental cues, or random assignment of roles. I will develop theory to explain this variation, and test this theory experimentally.