The Black-footed Ferret (i.e. a dirty dirty rat)

http://www.blackfootedferret.org

The Black-footed Ferret evolved around 3-4 million years ago and at one point thought to be extinct. The Black-footed Ferret has changed to fit it's environment by living off prairie dog for food but with human involvement to get rid of the prairie dogs because they thought of them as nothing but pests so when they were getting rid of them they also noticed a severe decease in the ferret's population when the prairie dog's population. When people noticed this they stopped killing prairie dogs and tried to save the ferrets. This is a good example of evolution because the ferrets rely on the prairie dogs to survive.