Zombies Of The Future

I think the most likely way that humans will become zombies is through the evolution of the toxoplasma gondii parasite.

The toxoplasma gondii parasite live an breeds in the intestine of the common cat. When a rat comes into contact with infected cats' feces it too becomes infected. Amazingly, the infection reaches the rat's brain and its normal behaviours is altered.
The rat will completely ignore its survival instinct and become attracted to cats and cats' urine. This leads to the rat becoming easy prey for any nearby cats.
One a cat has digested an infected rat, the parasite grows inside the cat's intestines and the cycle begins all over again.

I find it amazing how a simple parasite can infect a brain and alter a huge part of it completely.
I think it is only a matter of time before the parasite evolves and moves onto larger mammals, and eventually humans.

In the future it is highly possible that we could find ourselves faced with a parasite that turns alters our behaviours, and basically making us into zombies, as we pursue whatever needs the parasite has. A scary thought? For me yes. Simply because it is realistic. Evolution is a fact, and it is only a matter of time before it catches up with us.