Remember that scene in The Princess Bride, where Cary Elwes doubts the existence of 'rodents of unusual size,' and then is promptly attacked by one? Well all of us doubters could someday soon find ourselves in the same situation, according to University of Leicester's Dr. Jan Zalasiewicz.
A scientist from the England university's Department of Geology, Dr. Zalasiewicz firmly believes that rats will eventually grow bigger and occupy even more of the ecospace than they currently do, and he's got some pretty damn good points to support the wild theory. The long and short of it is that even the smallest of rodents have proven themselves nearly impossibly to eradicate when they find their way onto islands, and that they're so dominant that they've already managed to drive species native to those islands to extinction. "As a result, ecospace is being emptied," says Zalasiewicz, "and rats are in a good position to re-fill a significant chunk of it, in the mid to far geological future."
His theories get even more frightening when you realize that it's not at all uncommon for dominant animals to evolve, as they conquer and adapt to new environments. It's a natural part of evolution, and just as mammals like horses and mastodons evolved from small mouse-sized animals after the dinosaurs died off, Zalasiewicz believes that the rats of the world will also grow to much larger sizes, as they begin to occupy more of that ecospace. "Given enough time, rats could probably grow to be at least as large as the capybara, the world’s largest rodent, that lives today – that can reach 80 kilos," he says. "If the ecospace was sufficiently empty, then they could get larger still."
Though he has no way of knowing when, Dr. Zalasiewicz predicts that rats will be major players in the geological future of our planet, and that they will indeed spawn descendants that are much larger, and more advanced, than the modern day pests we consider them to be.
Check out the video below, where Zalasiewicz explains more of his terrifying theory.