system
Given the following post, respond as if you're commenting on Reddit:
human
[Dead Space] How are the first Necromorphs created?

The marker gets people to kill each other to make bodies to be converted, but how is the first Necromorph made with nothing to infect/create it?
gpt
The markers emit guided electromagnetic pulses which subtly alter the genetic code and proteins of nearby corpses to re-animate them.  The markers are capable of very precise and subtle electromagnetic manipulation of surrounding objects.

So basically xray, gamma rays and radio waves that modify the atomic structure of surrounding brains and bodies.