The Primate Diaries reviews a study by The American Naturalist describing how competitive bacteria form cooperative colonies. These high-level patterns emerge despite the fact that individuals in the colony behave selfishly.
To understand the emergence of apparent cooperation, consider ants on a sidewalk:
Have you ever wondered why ant trails in the city so often fall along cracks in the pavement or in gaps between the cement? The ants certainly didn’t plan this out in advance. It occurs based on the collective behavior of individual ants and the external forces that shape the outcome. When there are only a few ants following a pheromone trail the likelihood that they’ll be stepped on by a random pedestrian is fairly low. But once thousands of ants begin crossing back and forth continuously it’s bound to happen. When it does the pheromone trail is disturbed and the ants must adjust their path as a result. After multiple such disturbances the path is accidentally laid down inside one of these gaps where the ant trail is now protected from foot traffic. A stable system has now emerged without any one individual responsible for its development nor even understanding how or why it works.
Bacteria form patterns via the same principle:
A similar result can be found when the [bacteria] are all pushing each other outwards as they reproduce. The narrow passages within the emerging labyrinth are what allow nutrients to flow to the bacteria along all sides of their structure. However, when the collective mechanical push causes one of the labyrinth passages to narrow, the cells on the inside can’t get enough nutrients to reproduce and they slow their growth. This causes the labyrinth passage to expand once again as the cells die off naturally, allowing equilibrium to return.
As remarkable as it may seem, complex cooperative systems are the end result of nothing more than the collective behavior of individuals and the external forces that shape their outcome.
I find this fascinating from an evolutionary perspective: This is not conscious cooperation as we understand it, but a good example of how such behavioral (dare I say “moral”?) tendencies might evolve in more complex organisms.
The author seems to think emergent processes such as this might in fact kick in as human population stresses the natural resources of Earth – hopefully helping us out of a sticky situation:
It’s possible that the human species is now approaching a level of global saturation that the [bacteria] were forced to respond to in their microhabitats. Will we respond the same way?
While the prospects are certainly dire it’s somewhat reassuring to know that, while our individual actions will continue to be important, there may be natural systems in place to help shape the outcome whether we’re aware of it happening or not.
Maybe, but I’m sceptical that we’ll be willing to wait for natural processes to solve these problems for us. One hopes that we don’t have to squash too many people on the sidewalk before figuring out a workable solution.