[user104658]

I mean in theory it's true; if you're actually sending out a ship to colonise a new world, you'd want as few men on it as possible. None at all if frozen sperm is viable, but even if it's not, you'd probably still want a ratio of 1-in-5 being men or something like that. Obviously you don't want it being too low or you're going to get an awful lot of first-cousin inbreeding after a generation or two.