I apologize, but I am STILL a bit confused here. Am I to understand that the population cannot increase beyond 25 unless another one of the collections is completed (I already have completed the pebbles collection)? Initially, I figured it was because there was not enough housing, so I had them completed the only construction appearing, which turned out to be the sewing hut, and didn't make any difference (yeah, I know...call me 'dense!')

Can someone please lay it out for me here -- how the population progresses? I don't understand why this was not included in the rather lengthy strategy guide provided. I printed it out and use it as a handy guideline. Perhaps I am missing something?