Rock, Paper, Toxins

By Davide Castelvecchi
From Science News, November 3rd, 2007; Vol.172 #18 (p. 278)

In many ecosystems, several competing species coexist because none is best at everything. Tobias Reichenbach of the Ludwig Maximilian University in Munich and his colleagues ran computer simulations of three virtual bacteria species fighting a sort of rock-paper-scissors game.

One species produces a toxin. A second is immune to the toxin and outcompetes the first. A third species is sensitive to the toxin but can overtake the second species because it’s unburdened by the metabolic cost of producing an antidote. Each virtual population, shown here in a different color, propagates in waves as it pushes aside its weaker competitor while being chased by the stronger one, the researchers explain in an upcoming Physical Review Letters. Scientists have observed similar patterns among certain marine organisms.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s