Question: If there was a zombie apocalypse, what would be the cause of it?

Samuel Ellis answered on 10 Mar 2015:

In theory there are actually a number of ways ‘zombies’ could happen, or at least something like zombies.

One way would be some sort of brain parasite. There are actually many examples of parasites in nature which do actually change the behaviour of their host, such as making insects sit on the tips of grass so they get eaten by herbivores and the parasite can be passed on! This doesn’t happen in humans now, but in theory it is possible..

Some infections can also change people, with one famous example being ‘mad cow disease’ when it spreads to humans. It can make people delirious and lose coordination. Another is rabies, which is known to make sufferers violent. It is not impossible that a disease could make people act like zombies!

And in reality, zombies kind of already happened. The name comes from voodoo practises in Haiti, where there were thought to be real cases of voodoo priests using natural chemicals to put victims into a trance like state with limited brain function, then using them as mindless workers on farms!