Evolutionary Community Ecology

Dr Jan Frederik Gogarten

Our Research

Humans are changing our planet at unprecedented rates; temperatures are rapidly rising, human activities in remaining animal habitats are increasing, and the biomass of animals on the planet is estimated to have declined by more than 85%, as humans and their livestock increased. In the face of these rapid changes, the composition of remaining animal communities is shifting. The altered composition of these communities has cascading impacts on these animals’ behaviour and ecology. Rich communities of (micro-) organisms are found within and on each of these animals, while the animals, in turn, live in complex social groups and interact with other animal species through trophic links, such as predator-prey relationships, as well as diverse communities of vectors. Transmission of microorganisms sometimes occurs through these interactions, both between animals of the same species, but between those of different species as well. Humans are increasingly part of these interaction networks and pathogen transmission from animals to humans is occurring at increasing rates. Indeed, emerging zoonotic disease are an increasing threat to human health and most of these diseases have their origins in wildlife. Microorganisms and their associated diseases also influence animal populations’ persistence and conservation, with some spilling over to animals from humans as well. The research group ‘evolutionary community ecology’ explores how the changing composition of animal communities has cascading impacts on their microbial communities, diseases, and rates of transmission, including to humans.

Recent practical and theoretical advances in the field of community ecology provide an opportunity to identify and better understand the interactions relevant to the emergence and spread of pathogens in these changing contexts. The group will aim to develop and use flexible modelling frameworks for incorporating these multiple scales of biological organization, from within hosts, to landscape and regional processes, now allow for these processes to be disentangled. This is driven by the incorporation of an evolutionary framework, which provides data to detect which of these processes drive community assembly at various spatial and temporal scales. Indeed, analyses of the phylogenetic structuring of hosts and microorganisms can reveal patterns of selection and interactions between microorganisms, while phylogenetic analyses can reveal the histories of host-switching or codivergence. Ignoring animal communities and between species interactions can have dramatic unintended consequences for management efforts.

Links between biodiversity and human health remain contentious. On the one hand, high levels of animal biodiversity are predicted to harbor high microbial diversity, some of which may be pathogenic to humans. On the other hand, high levels of biodiversity have, particularly at small and intermediate scales, been shown to decrease the risk of some diseases for humans. For example, the dilution effect hypothesizes that the transmission of specific pathogens may increase as biodiversity declines, with the number of suitable hosts declining as biodiversity increases. Despite the appeal for universal rules linking biodiversity, habitat disturbance and disease risk, such patterns have not emerged. Rather, there is increasing awareness that local data on animal biodiversity, their microbial communities, and rates of transmission are needed to quantify context specific disease risk to inform local disease mitigation strategies. Thus, data on the distribution of hosts and their microorganisms is the foundation for understanding of the dynamics of disease emergence risk in our changing world. The emerging field of eDNA, which leverages high-throughput sequencing technologies to generate sequence information about hosts and microbes at large scales, is used by the group to bring the field of evolutionary community ecology to bear on the critical topic of disease emergence risk.

Interested in joining or collaborating with the Evolutionary Community Ecology group? Please do get in touch!