Co-evolution of ecosystems and their environments: Modeling the evolution of ecosystem-level responses to, and impacts on, environmental temperature
Date
2025
Authors
Febvre, Camille
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Abstract
Throughout the history of life on Earth, major changes in both the environment and the biota have occurred. Organisms have simultaneously adapted to and affected a tremendous variety of physical and biological conditions. Many species alive today engage in niche construction: their modifications to the environment feed back on their own evolution. Some extant species also affect the evolutionary pressures experienced by other species. However, while organisms are known to affect both the environment and the evolution of their own and other species, a general understanding of how organismal impacts on the environment evolve in ecosystems, and how these impacts feed back on ecosystem characteristics, is still lacking. This is necessary for understanding Earth system evolution and the pressures that drive the evolution of macroecological patterns.
In this dissertation, I modify a model of ecology and evolution called the Tangled Nature (TaNa) model to investigate ecosystem-level responses to and impacts on temperature. I first characterize how ecosystem properties depend on temperature, and find that ecosystem survival probability, species richness, and ecological interaction strengths are strongly temperature dependent in different ways.
Next, I couple this temperature-dependent version of the TaNa (the TaNa+T) with a climate model and enable organisms to increase or reduce atmospheric carbon, thus affecting the climate. In this version, called the Tangled Nature + Climate (TaNC) model, I demonstrate and characterize ecosystem-level niche construction, showing that ecosystems in the TaNC evolve toward cooler temperatures where death rates are reduced, and this can feed back on ecosystem properties, increasing ecosystem survival probability and reducing species richness and abundance.
I then test the sensitivity of the TaNC to assumptions about how species respond to and affect the environment. I find that species with similar thermal optima of reproduction do not modify the climate to maximize reproduction. Instead, minimizing death rates guides the evolution of ecological impacts on the environment.
Finally, I probe into ecosystem-level inheritance by making species' responses to and impacts on the environment heritable during speciation. Inheritance of species-environment interactions increases ecosystem extinction probability, but surviving ecosystems acquire larger species richness and abundance when thermal optima of reproduction are heritable.
Overall, this work illustrates general properties of ecosystem-environment coevolution, making an important contribution to Earth science and Eco-Evolutionary feedbacks and providing a powerful tool for further investigation of ecosystem evolution.
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Keywords
Ecology, Evolution, Climate, Niche-construction