system
Given the following post, respond as if you're commenting on Reddit:
human
If someone had been dead pre-zombies, would he come back to life after being bitten?

Consider any universe. World War Z, Dead Island, Walking Dead, etc. I'm basically saying that if someone died of natural causes (or unnatural, whatever) before the "patient zero" of the zombie apocalypse, would he come back to life when bitten?
gpt
It depends on the type of zombification (i.e. viral, parasitic, etc) but generally, the process requires piggybacking on some of the victim's metabolism in some way to affect the rapid changes. For example, viruses rely on existing cell replication to replicate themselves, so introducing one to dead cells doesn't do much. It's analogous to turning the steering wheel on a car. It doesn't do much if the car isn't already moving.

That said, it takes a while after death for body functions to cease completely, so some infections could feasibly still take over a *recently* deceased body.