A wolf pack’s return to Yellowstone rewired the entire ecosystem, and a biologist wants to know why that happened—and why it doesn’t happen everywhere. The researcher will analyse decades of data from Yellowstone, Trinidadian streams, and silvereye birds colonising Pacific islands to build computer simulations of species interaction networks. By simplifying those simulations, they aim to identify exactly how a shift in predation regime—the arrival or loss of a top predator—triggers cascading ecological and evolutionary changes, or fails to. This matters because predators are disappearing and reappearing worldwide, yet the consequences are unpredictable. Trophic cascades, rapid life-history shifts, and the “island rule” (where island animals evolve to be smaller or larger) are all attributed to predation changes, but the patterns are inconsistent, sparking scientific disagreement. This is fundamental science with no immediate practical application. If successful, it will produce general theory explaining when and why predation shifts reshape ecosystems and evolution. That theory could eventually inform conservation decisions—for example, predicting whether reintroducing a predator will restore an ecosystem or leave it unchanged—but the primary goal is to resolve a long-standing puzzle in ecology and evolutionary biology.
View original technical description
What am I going to do? Identify the causes of i) ecological changes in the species interaction network of the Yellowstone ecosystem, ii) ecological and micro-evolutionary changes in the species interaction networks of freshwater streams in Trinidad observed over 20-30 generations and iii) macro-evolutionary changes in silvereyes (passerine birds) that repeatedly colonise oceanic islands from the Australian mainland before modifying and adapting to the island species interaction networks they become part of. In addressing these system-specific questions I will generate general new theory into the ecological, micro-, and macro-evolutionary consequences of changes in predation regime. Why am I going to do this? Changes in predation regime are occurring across the globe. They are also thought to have generated the patterns seen in each of my systems. More generally, they have been argued to be responsible for striking patterns of ecological and evolutionary change such as trophic cascades, rapid life history and phenotypic trait adaptation in aquatic ecosystems, and macro-evolutionary patterns such as the island rule. However, although such dynamics are widespread, they are not universal, and this has generated disagreement over the consequences of shifts in predation regime. How am I going to do this? It is impossible to run replicated experiments to investigate how a change in predation regime impacts species interaction networks across ecological and evolutionary timescales, so an alternative approach is required. I have selected my study systems because of the remarkable amounts of data available, and these data will allow me to construct and parameterise complex simulations of species interaction networks. I will then use a highly innovative approach to simplify the simulations to identify the role of a shift in predation regime in each system, and also create general, new, theory on the consequences of shifts in predation regime.
Plain English summaries and category classifications on this site are generated by AI and may not perfectly reflect the original research.
Is something wrong? Let us know