14 DAY TRIAL // One of the main questions plaguing evolutionists ever since Darwin wrote his theory is on how cooperative behavior appeared, and how come it doesn't go away from relationships between individuals of the same species. That is to say, the evolution theory holds that only the strong members of each species survive, while the weaker ones get filtered out. And that means that cooperation should not exist, on account of the fact that it would potentially allow for weaker individuals to gain an unfair advantage over stronger ones and eliminate the latter.
Now, researchers at the Massachusetts Institute of Technology believe they may have found an answer to this question. They applied game theory, a popular and fairly accurate scientific method of analysis, to the natural world, and the results of their effort were published in the April 6th online issue of the scientific journal Nature.
The study was led by Department of Physics Pappalardo postdoctoral fellow Jeff Gore. He used yeasts as a target for research, on account of the fact that they have no thoughts or feelings, which may interfere with the logic processes and therefore make their decisions only based on genetic impulses.
“You can apply game theory to biological interactions and in some ways it's more broadly applicable than it is in humans,” the leader, who is also the lead author of the Nature study, said. He explained that, even though game theory was usually used in the military and in economy, its mathematical formulas could also be applied to the animal world, in order to predict individuals' or species' behaviors under different circumstances, ranging from ecosystem shifts to the destruction of their habitat by climate change.
The study focused on the yeasts' actions when confronted with the prospect of eating sucrose, a food they were not particularly keen on. But they can eat it, as glucose is now available in the environment. Some of the microbes started producing invertase, the enzyme necessary to digest the sucrose into smaller sugars, which they could then absorb. The study revealed that a number of the microbes became “cheaters,” in that they did not help with the invertase-production process. They simply consumed the sugar that was available at the moment through the actions of “cooperators,” those that actually broke down the food.
An interesting find was that, no matter how many germs were placed in the same environment at first, the number of cheaters and cooperators seemed to even out in the long run. “It doesn't matter where you start. You always end up with equilibrium,” Gore explained. However, cooperators have one reason to do what they do, namely the fact that they get discretionary access to almost one percent of the stuff they generate. This tiny advantage is enough to make them want to continue what they are doing. Otherwise, every single cell in the colony would die.