Talk:Genetics

My Sim has black hair and her future husband has red hair. But my Sim's dad has blonde hair, and her future husband's dad does, too. Does that mean they could have a blonde baby? Sparrowsong 04:44, March 20, 2010 (UTC)

I think it could be possible. —Preceding unsigned comment added by DavidMC123 (talk • contribs) - Sign your comments with ~

Yeah, actually, it's even likelier that their children will have blonde hair rather than red. If your sim's dad is a pure blonde (that is, he has two blonde alleles), then your sim has one black allele and one blonde allele. Similarly, your sim's future husband has one red allele and one blonde allele if his dad was a pure blonde. So, there's a 50% chance that their children will have black hair (because black is dominant and will always be shown rather than the recessive allele). In 25% of the cases the child will be pure blonde and in the remaining cases the game will decide randomly if they're blonde or red-haired (because both red and blonde are recessive traits). All in all, there is a 37,5% chance that they'll have blonde children. Granted, all of this is assuming the grand-daddies were pure blondes. If they weren't, then it's a lot more complicated to foresee. Crusoe704 22:46, March 27, 2010 (UTC)

Skin Colors
The section on Skin Colors says:

"Skin colors work differently. The 4 skin tones are S1 (white), S2 (tanned), S3 (brown) and S4 (dark brown). They work on the same pattern of allele transmission, but the way the alleles are expressed depends on both. A person will have a skin tone chosen randomly between the tones of his alleles. A S2/S4 alleles person will have a skin ton of S2, S3 or S4, chosen randomly. S1, S2, S3 and S4 are equally recessive. Only alien skin tone seems to be dominant. Hence, a person with A/S1 will be green, always."

This implies something that I have not been able to verify in several "experiments", namely for example that a sim with S1/S4 alleles and an S4 skin tone could pass on anything other than S4 to her child. I tried this several times and it just doesn't happen. Two S4 people will always have S4 children, no matter what their genetic make-up is. My theory is that where the normal skin colors are concerned, the game does not store the alleles used to determine the sim's skin color, it only stores what color the sim is. So for example an S2 sim will always pass on the S2 skin allele to her children even if her parents were S1 and S3.

Alien skin (and maybe custom skin?) is treated like in the above quote however.

If there are no objections to this, I'll edit it in a couple days accordingly. Crusoe704 23:11, March 27, 2010 (UTC)