Re: ARGH ALIENS!!!!!!! *shakes fist*
Game, NO.
I'm not even with you right now.
I am NOT populating this save exclusively with aliens! I know I have an alien in the household (his son-in-law's child-aged daughter that everyone is helping raise). I know that we have alien plants and mother and daughter explored space today (we're doing collections). I know that out of 6 played households (excluding my "spouse farms" that I don't really play), 4 have at least one alien* (two adult aliens from abductions who've moved out on their own into two households, two recent abductions in two households--yeah, I aged up Octavia and moved her out, into a San Myshuno apartment with her bestie, so her dad could get married). That does NOT mean that the next generation will consist entirely of aliens!
Are you listening to me?
Apparently the answer to that is NO, you are NOT listening to me.
(I've often felt that the game does more of what you seem to allow, such as if you have parents do flashcards with toddlers and help children and teens with homework, parents will autonomously do flashcards with toddlers and help children and teens with homework. Ditto for if you have a lot of babies they get a lot of whims for babies. If your Sim has a near-death brush with cold or fire the game will throw more cold or fire at you. But... NO.)
Yeah, I used MCCC to clear that. NO.
* If you're curious, the other two households are 100% vampire and 100% mermaid.