i heard a theory that all of the people on the island were needed because the world was gonna end so they chose people of different races to create a good gene pool and erased their memory, made it look like their plane crashed and put them on this secluded island so the human race would survive. this would explain why they havent seen a plane or a boat, because there is no one else on earth( im not exactly sure about the others)

by the way, have any of you read The City OF Ember? it has the same concept about the survival of the human race so they put the last people in this underground cave. I think this theory is most plausable.

i don't know but it kind of reminds me of the movie the island, where the seclude the clones, and tell them the world has ended.
but that has nothing to do with this because nobody told them the world ended, so it doesn't matter. hahah.

The reason the others are taking the kids could be that they need them to grow up healthy so they could have healthy children