Let's suppose I am planning to create a simulation of an entire continent at some point in the past (let's say, around 0 A.D). Is it feasible to spawn a hundred million actors that interact with each other and their environments? Having them reproduce, extract resources, etc?

The fact is that I actually want to create a simulation that allows me to zoom in from a view of the entire continent up to a single village, and interact with it. (Think as if you could keep zooming in the campaign map of any Total War game and the transition to the battle map was seamless, not a change of the "game mode").

By the way, I have never made a game in my entire life (I have programmed normal desktop applications, though), so I am really having trouble wrapping my head around how to implement such a thing. Even while thinking about how to implement a simple population simulator, without a graphical interface, I think that the O(n) complexity of traversing an array and telling all people to get one year older each time the program ticks is kind of stupid.

Any kind help would be greatly appreciated :)

EDIT: After being put on hold, I shall specify a question. How would you implement a simulation of all basic human dynamics (reproduction, resource consumption) in an entire continent (with millions of people)?