As seen in ...
Laboratories around the world.
What is it?
You know all that conversy out there about stem cell research? Well, the whole thing with stem cells is that they can basically be used to re-generate dead cells. Particularly of interest to zombologists like ourselves is neurogenesis, the method by which they can re-grow dead brain tissue.
You can see where this is going.
How it can result in zombies:
You wanted the undead to make an appearance in this article? Well, here you go, you creepy bastards.
Science can pretty much save you from anything but brain death; they can swap out organs but when the brain turns to mush, you're gone. Right?
Well, not for long. They're already able to re-grow the brains of comatose head trauma patients until they wake up and walk around again.
Couple that with the new ability to keep a dead body in a state of suspended animation so that it can be brought back to life later, and soon we'll be able to bring back the dead, as long as we get to them quickly enough.
That sounds great, right? Well, this lab dedicated to "reanimation research" (yes, that's what they call it) explains how the process of "reanimating" a person creates a problem. It causes the brain to die off from the outside in. The outside being the cortex, the nice part of you that makes humans human. That just leaves the part that controls basic motor function and primitive instincts behind.
Reanimation research (artist's rendering)
You don't need the cortex to survive; all you need is the stem and you'll still be able to mindlessly walk and eat and enjoy Grey's Anatomy. This is how chickens can keep walking around after they've been beheaded (including one case where the chicken lived for 18 months without a head).
So, you take a brain dead patient, use these techniques to re-grow the brain stem, and you now have a mindless body shambling around, no thoughts and no personality, nothing but a cloud of base instincts and impulses.
That, ladies and gentlemen, is what we like to call a real, live, undead fucking zombie. So there.
Chances this could cause a zombie apocalypse:
Think about it. Under every legal system in the world, all rights and responsibilities are terminated at death. All it takes is someone with resources and a need for a mindless workforce of totally obedient slave labor.
How long until somebody tries this? We're betting somebody in the world, maybe North Korea, will have a working zombie by Christmas.