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Tristan Ursell’s work featured in Quanta Magazine

Tristan Ursell at the University of Oregon, inspired by Kerr and Bohannan’s work, wanted to take it one step further. Although their study had shown that the distribution of organisms was key to the development of rock-paper-scissors, the environments in their experiments didn’t have physical barriers that would prevent the bacteria from moving about. The natural world is nothing like that: Whether a microbe is living on a plant’s roots or snuggled up somewhere in our intestines, its environment is filled with obstructions. Ursell, a biophysicist rather than a microbiologist, decided to create a series of computer models to see how physical obstacles could alter the rock-paper-scissors cycles.

Going into the project, Ursell expected that the obstacles might have minor consequences for the simulation. “I did not anticipate that it would in some cases completely flip over the stability,” he said.

Why Saving Single Species Isn’t Enough

Pitting two species against each other in an open space, for example, typically ended with one replacing the other. But if the landscape in Ursell’s computer model had barriers, both species could often coexist. Meanwhile, three species locked in a rock-paper-scissors game in an open space could coexist by cycling in and out of dominance. Introducing a barrier into their world often led to one species eliminating the others.

You can read the full article here.