Yeast experiment offers fresh insights on the nature of natural selection

An experiment involving yeast has revealed a method that allows organizations to avoid the “tragedy of the commons,” the situation in which individuals take advantage of shared resources — such as common grazing land for animals — without paying for their use or maintenance.

By performing the experiment on small organisms, researchers have shown a way to avert a prediction of evolution theory: that natural selection necessarily favors “cheaters” — individual organisms determined to game the system — over “cooperators” who obey the rules.

The experiment, reported in Proceedings of the National Academy of Sciences, reveals a way in which evolutionary adaptation via mutations can benefit cooperators over cheaters.

"It gives a larger role to adaptation," said Adam Waite, a graduate student in molecular and cellular biology at the University of Washington, who performed the research with his supervisor, Wenying Shou, at the Fred Hutchinson Cancer Research Center in Seattle. "While natural selection should help cheaters, it can also help cooperators defeat cheaters."