So I've scanned through the forums and couldn't find what i was looking for... I'm playing my first gen going onto my second gen, and I haven't really noticed any sims being introduced into family's ...
Unfortunately, left to their own devices townies don't do anything except age and die. They don't have kids. If they even bother to go to work or school, they don't learn skills or progress. They don't take care of their pets or clean their house. Story progression was only sort of implemented in this game, much to it's detriment. At least the lack of any progression in Sims 2 meant there were never sick pets or nasty houses. I'd rather have that then what we ended up with.