PAGING LOTKE AND VOLTERRA. Predator cycles are part of the balance of nature.

It is a desperate - and likely endless - fight to protect the delicate ecology of the world's first national park, home to a rogue colony of Lake Michigan lake trout that biologists believe was illegally planted in Yellowstone Lake by self-serving anglers hungry for bigger trout to fry.

That is, until the bigger trout population falls into a Malthusian trap.

A model of biological evolution is considered, based on Lotke-Volterra population models (ecological interaction), with mutation being modelled by introducing new species with random ecological connections. It is found that the system evolves away from the ecological equilibrium point to a sort of steady-state balancing extinction with speciation.

That's the scientific version. The popular version goes like this.

Lake trout belong in Lake Michigan. The big lake gets out of whack without a top predator to cull its schools of smaller prey fish, including pesky alewives. But overfishing, pollution and an onslaught of invasive species combined to wipe out the king of the Lake Michigan food chain about 50 years ago.

Today, Lake Michigan lake trout are hatchery-raised and, like a dose of antibiotics, dispensed annually to help keep swarms of prey fish in check.

But in an absurd twist of ecological irony, it's a different story in Yellowstone.

In Yellowstone, Lake Michigan lake trout are the disease.

Read the rest of the story. It's depressing.

I also found this predator cycle simulation that appears to provide an online interactive application.