Eco-evolutionary dynamics of early animals

Supervisor: Dr Emily Mitchell

Co-Supervisor: Dr Charlotte Kenchington

Project Summary

This project will investigate how different processes influence the early evolution of animals in the Ediacaran time period.

Life has existed on Earth for more than 3.5 billion years, but it is only around 600 million years ago, during the Ediacaran time period (635 – 541 Ma), that animals appear in the rock record. It is during the Ediacaran that animals evolved some of their most important traits: most obviously large body-size but also tissue-differentiation, mobility, bilateral symmetry and ecosystem engineering (reef-building).  Over the last ten years, mathematical ecological approaches have demonstrated how previously elusive biological details can be extracted from the Ediacaran fossil record. This proposal will tap into the exceptionally rich biological information captured in the Ediacaran fossil record and use using mathematical models to investigate the underlying processes that drive the evolution of early animals.

This project will use theoretical models of Ediacaran communities to investigate taxa life-history traits and use these traits to develop dynamic models of Ediacaran eco-evolutionary dynamics to investigate how difference processes influence Ediacaran evolution.  In contrast to modern marine systems, the oldest Ediacaran benthic organisms do not interact much with each other, i.e. resource competition, facilitation and mutualisms are relatively limited.  Instead, reproductive dynamics appears key to Ediacaran life.  Mechanistic models can be used to investigate these different processes, with the outputs compared to the available data to determine which models best reflect observed diversity patterns, and so which processes are key.

References

Mitchell, E. G., Kenchington, C. G., Liu, A. G., Matthews, J. J., & Butterfield, N. J. (2015). Reconstructing the reproductive mode of an Ediacaran macro-organism. Nature, 524(7565), 343.,

Mitchell, E. G., Harris, S., Kenchington, C. G., Vixseboxse, P., Roberts, L., Clark, C., ... & Wilby, P. R. (2019). The importance of neutral over niche processes in structuring Ediacaran early animal communities. Ecology Letters  22(12) 2028-2038.,

Eden, R., Manica, A. and Mitchell, E.G., 2022. Metacommunity analyses show an increase in ecological specialisation throughout the Ediacaran period. PLoS Biology, 20(5), p.e3001289.