The Gaia hypothesis (Lovelock & Margulis 1974) proposes that organisms have a significant effect on the physical and chemical environment on Earth, and that feedback loops between organisms and the environment have evolved that stabilize the environment. According to Gaia, such positive feedback loops create homeostasis that make Earth suitable for life. The first part of the hypothesis has overwhelming empirical support, but the evolution of positive feedback loops is strongly disputed, particularly by evolutionary biologists (Kirchner 2002). Nevertheless, that second part of the hypothesis can be tested by “Darwinizing” Gaia and letting organisms with multiple traits evolve in silico using computer simulations. By parameterizing these traits using empirical data, it becomes possible to critically evaluate Gaia.
Phytoplankton play an important role in binding CO2, thus affecting climate change. In a recent paper we showed that phenotypic plasticity and adaptation of a species of diatom (a type of phytoplankton) is underpinned by differential allelic expression (DAE), and that this enables this species to survive in the extremely fluctuating environmental conditions of the polar oceans (Mock et al. (2017) Nature 541: 536-540). Our study showed that alleles with the highest level of DAE also showed the fastest rate of evolution. Using these data, we recently built a simulation model (called DAEsy-World see:
https://github.com/ThatPerson/Gaia), which demonstrated that both positive and negative feedback loops can evolve, which can either stabilize or destabilize the homeostasis of the climatic system, respectively. In this Post Graduate research project (MSc by Research or PhD), the student will build on the model with the aim to critically evaluate Gaia and examine positive and negative feedback loops between phytoplankton and the environment under different scenarios of global warming.
For more information on the supervisor for this project, please go here:
https://www.uea.ac.uk/environmental-sciences/people/profile/c-van-oosterhout Type of programme: PhD
Project start date: October 2019
Mode of study: Full time
Entry requirements: Acceptable first degree - BSc in Computer Science, Biology, Environmental Sciences
The standard minimum entry requirement is 2:1.
References
i) DAEsy-World: https://github.com/ThatPerson/Gaia.
ii) Kirchner, J. W. (2002). The Gaia hypothesis: fact, theory, and wishful thinking. Climatic Change 52, 391-408.
iii) Lovelock JE and Margulis L (1974). Atmospheric homeostasis by and for the biosphere: The Gaia Hypothesis’. Tellus 26, 2–9.
iv) Mock T et al. (2017). Evolutionary genomics of the cold-adapted diatom Fragilariopsis cylindrus. Nature 541, 536-540.
