But for humans, the objective function is survival. Evolution has created us human beings, and evolution works by survival of the fittest. So the objective is survival.
How do we digitize this objective of survival, so that it can be used to train models leading to AGI?
2) Don't. It's incredibly hard to build a correct value function for an AGI that won't unintentionally kill everyone. "Successfully replicate" is precisely the kind of thing to avoid. That's directly the "gray goo" scenario: https://en.wikipedia.org/wiki/Gray_goo