> "Studies in closed-system ecology are underway or have been demonstrated to some extent with Biosphere-2 or BIOS-3."

And so far demonstrated that it's not feasible.

> It can be seen that regarding biological feasibility, in particular genetics, population sizes in the 10^3 - 10^4 range are required

There is no mention of education. The assumption is that neolithic villages are a good model, but neolithic villagers didn't operate an interstellar ship.

Do all children in the ship need the equivalent of, say, a high school education? If so, the time needed to educate them takes away from time needed to raise food, manage sewage treatment systems, etc.

In Biosphere-2, the staff spent all their time on the biosphere, with no spare time for raising and educating children.