Mutation happens when changes are made to the simplest genetic materials: DNA and RNA. It can be caused by a copying error brought about by outside influences like ultraviolet radiation, chemical mutagens, or viruses. Mutation is natural - that doesn't include radiation and chemical mutations - as sometimes it's nature's way to evolve by natural selection. Like nature's beta testers.

For example, a tree frog is born with brown skin but its species are naturally green. Since the brown tree frog is able to hide from predators more effectively, it has more chances of survival. It might even give rise to a higher number of brown tree tree frogs than the green ones. But some mutations aren't so useful.

Now, a newborn duckling named Stumpy was born with two extra feet at New Forest, Hampshire, UK. The owner of the duckling, Nicky Janaway says that he was absolutely stumped. He said, "It was absolutely bizarre. I was thinking 'he's got too many legs' and I kept counting 'one, two, three, four... He's eating and surviving so far and he is running about with those extra legs acting like stabilizers."

Reports of these sorts of mutations are recorded around the world. Makes us wonder a bit. What's next? Pigs with wings?