Reignfire

I was just wondering if all of the series stayed inside the original continuity. All life on earth was destroyed except for those on the Macross. Every human character in every series had to be decended from the Macross population right? Exactly how many humans were aboard the ship and how many zentradi chose to enter human society? Wouldn't the micronized zentradi out number the earthlings? Just a few decades later in Macross 7 you see lots of fleets from earth fly through space housing huge populations of humans and zentradi. How can there be such a population growth in such a short time? Just curious.