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)

Strange Genetics
In my game, my sim Anna has black hair and green eyes and so do her parents. She married Parker Lawson who had brown hair and greyish eyes. His father had black hair and greyish eyes his mother had reddish hair and brown eyes. Anna and Parker had a child called Klaudia she had Bright blond hair and blue eyes unlike anyone in her family. Where did these genes come from. Anna didnt mess around with any other guy. And they had another child a boy called Alexander with Brown hair and green eyes. This is annoying me and she doesnt look like anyone in her family. Where did these genes come from???
 * Genetics is a bit weird, even in real life. There could be some hidden genetics in your sim, or maybe the game is just messing with you. If you have SimPE, try using that to look into their DNA. --W H  (Talk) 07:51, May 27, 2011 (UTC)

First born effect
Are there any hacks that automatically shake up the randomizer so i dont have to remember to do it myself? I always forget and end up with identical kids. It isnt normally a problem because most of my families only have one kid (its a large neighbourhood, sometimes I have trouble keeping track otherwise) but occasionally they have two and I dont realise I've forgotten until the kids grow up looking identical. Sims2addict9312 (talk) 08:53, September 10, 2012 (UTC)


 * Not that I'm aware of. The "batbox" has an option for that, but it has to be used manually, and I don't know how well it works. Dharden (talk) 12:12, September 10, 2012 (UTC)
 * Also, using the batbox randomizer will switch your game to neighborhood view, so don't forget to save before using the option.  Nikel  Talk  –  Vote!  08:56, September 11, 2012 (UTC)

Identical Twins
Can the game generate identical twins or do you have to make them yourself? (sims2) Sims2addict9312 (talk) 08:53, September 10, 2012 (UTC)


 * You can make them in CAS, but twins born in-game are always fraternal. You'd probably have to use SimPE to modify one twin. Dharden (talk) 12:12, September 10, 2012 (UTC)

Pointed ears
I am playing with a family of fairies. It consists of the mother, Yaroslava Tkachenko, the father, Branch Tkachenko and their sons Artem and Taras Tkachenko, and daughter, Oksana. The funny thing is that Artem who is toddler has pointed ears. There's nobody else in the family who has it. The question is how do he get that. Надія(hope),сла́ва (glory), Любов (love) ( talk here ) 16:51, October 6, 2012 (UTC) Lesya Zirka

Forget it I was wrong. Надія(hope),сла́ва (glory), Любов (love) ( talk here ) 21:48, October 6, 2012 (UTC) Lesya Zirka
 * Is it The Sims 2 or 3? If it's The Sims 2, you may also want to read this.  Nikel  Talk  –  Vote!  05:29, October 8, 2012 (UTC)

Concerning dominant traits

 * Two (dark) blue-eyed parents can have a brown-eyed child if one of the child's grandparents have brown eyes. Melody Tinker is an example of this. In real life, this is extremely rare. An individual carrying a brown-eye allele and a blue-eye allele is meant to express brown eyes (being the dominant trait); however if the blue-eye trait is expressed over the brown-eye trait then the individual may be mistaken as homozygous for blue-eyes (two blue-eye alleles), thus the individual's offspring is expected to have blue eyes too.
 * Can anyone confirm this as being true? Ѧüя◎ґ (talk) 21:43, June 14, 2014 (UTC)