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)

I've had twins that were almost but not quite identical before. --  C.Syde  ( talk &#124;  contribs ) 03:47, June 24, 2014 (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)

Don't think that's true. At least one of the parents has to have brown eyes or genetics for brown eyes to produce a child with brown eyes. Melody Tinker's eyes are different from the rest of her family because she was made in Create a Sim and / or Body Shop. Until further evidence turns up, I doubt that it's true.

It's also the same with Albany Capp and Richard and Anne Norman. Also when using the Tombstone of Life and Death or SimPE, one can see that Albany was actually created before his parents, meaning that he wasn't born in-game.  C.Syde  ( talk &#124;  contribs ) 02:58, June 15, 2014 (UTC)

Genetics
According to how SimPE / The Sims 2 works, there can only be one dominant genetic and one recessive. Looking at SimPE, it seems that if there are four different genetics available to inherit, one will be dominant, one will be recessive and the last two will be dropped completely.

Any ideas / agreements? --  C.Syde  ( talk &#124;  contribs ) 06:12, June 24, 2014 (UTC)
 * Each parent gives off one allele to their offspring. I assume that's what you mean when you say "the last two will be dropped completely". Ѧüя◎ґ (talk) 06:26, June 24, 2014 (UTC)

Yes. --  C.Syde  ( talk &#124;  contribs ) 06:27, June 24, 2014 (UTC)


 * For eye and hair color, what SimPE shows as "dominant" and "recessive" might be better thought of as "expressed" and "non-expressed". Each parent gives one allele, but it's possible for both to be dominant or recessive, in which case the game will randomly pick one to be expressed. Dharden (talk) 22:51, June 24, 2014 (UTC)


 * Skin tone is ... different. As far as I can tell, if alien-skin genetics are not involved, "Skintone" is the same on each side, and is the Sim's actual, expressed skin tone, while the "Skintone range" values are what got passed from the Sim's parents. So, a Sim might have "Skintone" values of 00000002-0000-0000-0000-000000000000, but "Skintone range" values of 00000001-0000-0000-0000-000000000000 and 00000003-0000-0000-0000-000000000000 . I'm not sure which one gets passed on, but since the Strangetown pre-mades that are missing "Skintone" have "Skintone range", I think it may be "Skintone range". If alien-skin genetics are involved, it appears that the "Dominant" side shows the Sim's expressed skin tone, while the "Recessive" side shows skin genetics received from the other parent. In these cases, the "Skintone" and "Skintone range" values on each side are the same. Dharden (talk) 23:40, June 24, 2014 (UTC)


 * If I am reading what the Prima guide for TS2 says about skin tone genetics right, and if Prima got it right way back then, if a Sim gets a gene for a skin tone that is outside the normal 00000001-0000-0000-0000-000000000000 to 00000004-0000-0000-0000-000000000000 range, skin tone selection becomes a straight 50/50 choice between the two skin tone genes that were passed on. I don't use custom skin tones or the mannequin tone, but this squares with what I have seen when looking at the Sim DNA of Sims with alien-skin genes. Dharden (talk) 15:18, June 25, 2014 (UTC)

For example?
For example, a child may have his/her mother's eye shape, but the father's eye size

Sure about that one? In all the times my Sims have had children, they've had either their mother's eyes or their father's eyes. Never their mother's eye shape but their father's eye size. Until further evidence turns up I doubt whether this fact is true. --  C.Syde  ( talk &#124;  contribs ) 08:39, June 24, 2014 (UTC)


 * I'm trying to recall why I concluded that eye shape and size are inherited separately. Dharden (talk) 22:32, June 24, 2014 (UTC)

I've removed that information, due to the lack of evidence suggesting that it is true. My past experience in-game also contradicts this. --  C.Syde  ( talk &#124;  contribs ) 04:02, June 26, 2014 (UTC)

Alien skintone always dominant? (TS2)
IME, this is not the case. At least, it is not the case when one of a child's parents is an alien-Sim hybrid with the alien skintone, and the other has a skintone other than the lightest. In those cases, even if the alien skin tone is passed on, the child may have a normal skin tone, and the alien skin tone may be recessive. I know this because I have observed it; one of the Sims in my current 'hood is dominant for brown eyes and medium skin, but carries alien eyes and alien skin as recessives. Dharden (talk) 13:35, June 24, 2014 (UTC)

I'll take your word for it, but I've never seen that happen. I've had brown eyes and brown hair as dominant alleles over alien genetics, and I've had mannequin skin tone as dominant over alien genetics. But I've never had a normal skin tone be dominant over alien / mannequin skin before. --  C.Syde  ( talk &#124;  contribs ) 19:07, June 24, 2014 (UTC)


 * I haven't seen it often, but I have seen it. IME, it only seems to happen if the hybrid parent is heterozygous for the alien skin tone. In that case, a passed-on gene for alien skin does not appear to be treated as dominant, and the resulting child can have both a normal skin tone and a non-expressed gene for the alien skin tone that can presumably be passed on. (I'll have to wait until they reach adulthood to find out for sure. but I see no reason to think that it could not happen.) Dharden (talk) 22:29, June 24, 2014 (UTC)

Grey hair
I know 00000005-0000-0000-0000-000000000000 is the code for grey hair, but I always thought that grey hair was *not* genetic. Dharden (talk) 02:35, July 10, 2014 (UTC)

Grey hair is not genetic, but I wasn't sure what else to do with that information. I was thinking of referencing it. --  C.Syde  ( talk &#124;  contribs ) 03:11, July 10, 2014 (UTC)

Could always just have a little note that says that gray hair is not genetic, but that is the code for it for reference purposes. Icemandeaf (talk) 03:16, July 10, 2014 (UTC)

Okay, maybe I'll do that. --  C.Syde  ( talk &#124;  contribs ) 03:20, July 10, 2014 (UTC)

TS2 Pet Genetics
So I was just browsing through my neighbourhood in SimPE (because one of my IRL personality traits is curious ), and one of the things I was checking was my sims' DNA. I noticed that my pet sims (specifically my two cats) have an allele for eye color that doesn't match any of the ones on this page. For example, Waggles has light green eyes and his dominant and recessive gene for eye color is  8de4d9a1-c401-4893-9a6c-588ab671ac0d , while Maria has dark green eyes and hers is  22a77e4a-1fc7-4098-b4e0-ddd29bb38ac5. Doing a quick Google search for any of the alleles for eye color listed on the page (eg.  32dee745-b6ce-419f-9e86-ae93802d2682 for brown) returns this Wiki and a bunch of pages about genetics in the game, but a Google search for any of these pet genes I discovered returns no result. Am I misunderstanding something, or does this merit an addition to the page? The Only Zac (talk) 23:49, January 27, 2016 (UTC)


 * Okay, so I've spent the last few hours thoroughly experimenting, and I've finally tracked down all the possible alleles for dog and cat eye colors (which are definitely different from Sim eye colors).  The only thing I couldn't figure out is which eye colors are dominant and which eye colors are recessive. Either way, I 'll update the page itself as soon as I can track down the eye color swatches in the game's package files. The Only Zac (talk) 03:40, January 28, 2016 (UTC)
 * Okeydokey, I've expanded the page with the new phenotypes and genetic codes, complete with the official eye swtaches extracted from the game files. I also included a fact I discovered about how only the right eyes of CAS-created hetero-chromatic pets are registered in their genetic code. The Only Zac (talk) 05:39, January 28, 2016 (UTC)

The Sims 2 Hair, Eye, and Skin Colour Thumbnails
Where exactly can I find the thumbnails provided in the Sims 2 Phenotypes section of the page? I can't find the thumbnails. Not even with SimPE. Yet someone must have found a way to extract them to be able to upload them to the Sims wiki, other than using print screen. ―  C.Syde  ( talk &#124;  contribs ) 22:20, January 28, 2016 (UTC)


 * I found the Cat and Dog eye color thumbnails in my Origin Libary\The Sims 2 Ultimate Collection\Fun with Pets\EP4\TSData\Res\UI\ui.package, so I assume the base game Sim eye colors are found in the equivalent package in your base game folder rather than Fun with Pets. If you want, I could find and extract them and upload them to Dropbox or something for you, it shouldn't be that hard since I know what to look for. The Only Zac (talk) 22:33, January 28, 2016 (UTC)
 * I just wanted to know where to locate them. Because if I do that, then I'm hoping to locate something else ― that I believe will be found in the same folder ― which previously hasn't been uploaded. ―  C.Syde  ( talk &#124;  contribs ) 22:36, January 28, 2016 (UTC)
 * Coolio, actually I almost ninja'd you with a reply because I did in fact just find them in my Origin Library\The Sims 2 Ultimate Collection\Double Deluxe\Base\TSData\Res\UI\ui.package. If you open it in SimPE, go to the jpa/tga/png Image type, and sort by Instance, they'll all be grouped together. Then you can just start at the beginning and press PgDown until you hit either a hair, eye, skin, or makeup thumbnail.
 * Do you mind if I ask what it is you're looking for? Don't worry, I won't get to it first and upload it before you or anything. :P The Only Zac (talk) 22:49, January 28, 2016 (UTC)
 * The Mannequin skin tone thumbnail. Although it's hidden and I've only ever seen it in debug mode. I've never seen the thumbnail uploaded online. ―  C.Syde  ( talk &#124;  contribs ) 22:52, January 28, 2016 (UTC)
 * Awesome, that'd be a great addition to the wiki. If you need any more help tracking it down, let me know. :) The Only Zac (talk) 23:00, January 28, 2016 (UTC)

Hair Genetics
I have a family consisted mostly of brunettes and red heads. Michael (Bachelor) had medium brown hair, which he passed to his first son, Mikah. When he remarried Melanie Song, a red head, and had a daughter, Nicole, she got the red head from her mom.

Now Nicole is all grown up and has started a family of her own. She married Noah, who has dark brown hair like his mother. However, their son was born blond.

I understand that genetics can be recessive, but I am not sure where this came from. Noah's mother had dark brown hair, like he does, and his father had russet hair. They don't have any family further back than that. As for Nicole, her mother doesn't have other family, but Michael's tree links him to (as many should know) Simis, Jocasta (his parents), Bella (sister) and Simis's parents, Enriqueta and Milton.

Do we know what they looked like? Both Simis and Jocasta AND Bella had dark hair, but Oakley's great grandparents are deceased so I have no idea what their hair color is. Is the blond just a glitch, maybe?Warriors Fan01 (talk) 17:46, February 22, 2016 (UTC)


 * By the family tree you described I assume you're playing The Sims 3, and according to the article The Sims 3 has a 10% mutation rate which would explain the seemingly random genetics showing up in Nicole and Noah's son. The Only Zac (talk) 00:48, March 11, 2016 (UTC)

Hair Genetics in The Sims 3?
I have a sim named Henry Moore who has brown hair. His wife, Lucy Moore, has blonde hair. In The Sims 3, whenever they have a baby who does not inherit Lucy's blonde hair, they always turn out with black hair. Can anyone explain why this happens? Absolutely no one in either of their families have black hair. I know TS3 has an unusually high genetic mutation rate, but I don't think that explains why their children turn out with black hair rather than brown hair, because it literally always happens.

(By the way, the fact that I wrote the game's name in italics is not for emphasis. I am just used to writing specific things such as game titles in italics, because they are written like that on articles) Mariaw (talk) 01:13, April 3, 2018 (UTC)


 * The mutation rate would still explain it, I think. If the mutation rate is set at 10% in your game, then I'd say that's the most likely culprit. You were just extremely fortunate to luckily have multiple babies with a mutated genome. Ѧüя◎ґ (talk) 01:21, April 3, 2018 (UTC)


 * I suppose that most likely the reason; plus, I do not have any mods for the game that lower the mutation rate (or any mods at all, for that matter). My only other guess was the root hair colour being darker than the base colour, but it's not dark enough to be considered black, and the children in question did indeed have completely black hair. I wish the game used the mutation rate for their eye colours instead, lol Mariaw (talk) 01:33, April 3, 2018 (UTC)


 * Chances are, there will be a higher chance that the baby will have blond hair. You see, genetics itself is basically all the data of the Sim, including their hair color, and the colors are sorted to be dominant or recessive. Both the mother and father have recessive, but still, the baby will have a higher chance of being blonde. IsaiahScribblenauts - Disscuss - My Fanon 01:42, April 3, 2018 (UTC)

Sims 4 Eye Colours
According to the article, in The Sims 4, "Eye color usually comes out as one of the parents, but it can also come out as anything in between the parents' own eye colors."

Through very extensive testing, I can prove this is entirely incorrect. What really happens is that the eye colours added in Patch 5 (Dark blue, dark blue-hazel, grey-brown hazel, olive green-hazel, and purple) have the same flag values set as already existing eye colours.

For example, if one parent has dark blue eyes and one parent has dark brown eyes, their child may turn out with grey eyes even if no one in their families have grey eyes; this is because dark blue and grey eyes share the same EyeColor flag; as such, the game cannot destinguish the two eye colours from each other, and if the child recieve the grey-eyed parent's eye colour, they have a 50/50 chance of having grey or dark blue eyes. Likewise with red (amber) and purple eyes, grey-brown hazel and light brown, olive green-hazel and pale green (light green), as well as dark blue-hazel and light green ('hazel blue' according to the files. I really don't see it, though.)

If anyone could figure out how to insert this information into the page profesionally (I don't think I am much good at making big edits), that would be great! Mariaw (talk) 23:19, August 2, 2018 (UTC)