Scale-free network [L] vs. Random network [R]

The architecture that pervades biological networks gives them an evolutionary edge by allowing them to evolve to perform new functions more rapidly than an alternative network design, according to computer simulations conducted at the University of Chicago.

Scientists have found the same intricate network architecture of evolution just about everywhere they look. This architecture characterizes the interaction network of proteins in yeast, worms, fruit flies and viruses, to name a few. But this same architecture also pervades social networks and even computer networks, affecting, for example, the functioning of the World Wide Web.

This organizing principle is what scientists call a “scale-free design.” A diagram of this design resembles the route maps of airline companies. “You have hubs that are highly linked with airplanes going in and out of those hubs,” Oikonomou said…

Oikonomou and Cluzel initiated his project to find out if network design conferred any kind of evolutionary advantage. They created a Darwinian computer simulation to compare the evolvability of this scale-free network design with a more random design in which all network components have approximately the same number of connections. They programmed this computer world to have random mutations and natural selection operate on its digital populations, then compared how long it took the two types of networks to evolve the ability to perform a new task.

The populations organized in scale-free networks evolved rapidly and smoothly, while randomly organized networks evolved slowly and in spurts following a succession of rare and beneficial random events.

“They followed drastically different evolutionary paths,” Cluzel said.

I must admit — if I was starting out, today — the science and technology of computational analysis and computer simulation would be a study target. Now that we have easier access to the horsepower required for much of this work, virtually any research can be aided by these processes.