Ok... Where did the third human on this planet come from?...
I don't think that's a scientific question, dear brother in Christ. In what way can the scientific method — direct observation, replicable experiments, falsifiability — engage it, let alone answer it?
As the novelist Robert Musil observed, "the reason God is such an embarrassment to science is that he was seen only once, before there were any trained observers around." The same situation applies to the "third human."
In short, yours is a philosophical/theological question, not a scientific one. Or so it seems to me, FWIW.