Tremendous efforts have been made to describe the Earth’s biodiversity and identify the processes that shape it. Evolutionary biology, and in particular speciation research, is at the very centre of this endeavour as it disentangles why and how taxa diversify. Over the last years, this field has been fuelled by the enormous advances in genomic technologies and computational power, which allow to address questions that were impossible to answer just two decades ago. We have gained a thorough understanding of the role of ecology in speciation and also begin to elucidate the underlying genomic processes, at least in some model-organisms. In addition, increasing interest has been paid to the role of culture in modifying selection pressures and shaping the genome of us humans. Cultural innovations such as farming allowed us to occupy novel habitats and changed the fitness landscape of our genome, but also initiated further behavioural alterations, for example different societal structures, leading to subsequent genomic changes.

Despite this growing body of evidence on the interplay between behaviour, genomes, and genetic diversity in humans, this topic has received less attention in other species. A recent study on killer- whales, a prominent example for culture in non-human animals, found genome-culture coevolution to be an important driver of population divergence. In birds, the type of mating system and in particular the mode of parental care influences speciation. It has also been shown that sociality reduces genetic diversity and inhibits diversification in spiders and similarly the evolution of eusociality in insects has consequences both at the genomic and the population level. However, we are lacking an overarching framework that explicitly integrates behavioural ecology with macroevolution to identify the factors and processes that link behavioural traits with genomic evolution and diversification processes. In my project, I will fill this gap by building the links in the explanatory chain that connect behavioural traits to diversification. To accomplish this, I will follow four parallel and complementary lines of research, which I outline here.