When Maxis created The Sims 2, one of the biggest features the devs were proud of was the generational system and especially the primary and recessive DNA system.
To show it properly, they created Europa, which later became Veronaville. The way to showcase the new features was simple: create families with huge generations and show how genetics could recur even after generations.
Thus the Capps and Montys were born. Inconsistently, many of them are genetically incorrect, but the primary and recessive DNA associated to them (albeit forced) still makes sense.
To give a perfect example: Goneril Capp was "born" with the primary DNA for red hair. She may have inherited her hair from Queen Thebe (Princess Cordelia Thebe I in The Sims 4), Consort's maternal grandmother.
But at some point someone had second thoughts and said, "You know what? Let's change genetics!" The genetic code was never changed, but Goneril went from being a redhead to a brunette, suggesting that she had instead inherited her brown hair from her maternal grandmother, Scribonia Capp, while both her parents have blonde hair.
I'm sure that in the vanilla game, if checked on simPe, Goneril still has the genetic code for red hair as primary genetics, while either she doesn't have the recessive DNA or it is identical to the primary one (so red hair, light skin and grey eyes). This means that Miranda's children, or any of Goneril's children, can have red hair IF Miranda and her siblings have the recessive gene for red hair, taken from their mother's primary gene.
In fixed versions of Veronaville, such as the one of meetme, if I'm not mistaken, Goneril's DNA has been fixed: brown hair as primary DNA and red hair as recessive, thus maintaining the DNA of both grandmothers/great-grandmothers.
In The Sims 4, there is no recessive DNA; unfortunately, the primary DNA itself is very broken, and children are often born with DNA that neither parent has. BUT I noticed a very appreciated detail even if it is something that cannot be obtained in the game via gameplay:
Princess Cordelia Thebe I has purple eyes.
Almost all of her descendants (except Andromache) have purple eyes:
Cordelia Thebe II have purple eyes.
Cordelia Thebe III have purple eyes.
Rodrigo Thebe have purple eyes.
Cordelia Thebe IV have purple eyes.
Cordelia Thebe V have purple eyes.
Arnessa Thebe have purple eyes.
AND Greta Laurent (Arnessa's grandchild) have purple eyes. Greta completely skipped her parents' brown eyes.
This is a perfect example of recessive genetics...
IF ONLY WE HAD IT
Another (forced) example that I recently noticed is the case of Cordelia Thebe III.
Cordelia Thebe III's parents are Cordelia Thebe II and a unknown sim.
Cordelia II have blonde hair (a blonde tending towards brown) Cordelia III has brown hair.
We may just assume that she inherited her brown hair from her mysterious father, but if you look closely at the family tree, her maternal grandfather, John Wilson Beard Beard, has brown hair. This could also be a forced recessive genetics.
If we want to talk about recessive genetics taken to the extreme...we can talk about Tybalt's children.
As far as I can remember, there are no black-haired Capp relatives (not from Contessa and Consort's branch and in Caliban's family they all have red hair) so we can assume that Celeste and Virgilio took their hair color from their biological mysterious mother (yes I don't want to destroy your dreams but Virgilio has dyed hair, he have black eyebrows and facial hair, he is not blond.) while Beatrice...inherited brown hair from Scribonia Capp (Contessa's mother) or Andromache Thebe (Consort's mother). There are other relatives with brown hair, but these two are the closest prime examples.
Dante could also be a good example of recessive genetics.
Romeo has black hair, Juliette has red. Dante could have inherited his brown hair from his great-grandmother Isabella Monty or any other Capp relative.
Fun fact: Isabella's genetic code for hair is BLONDE. Isabella was actually supposed to be blonde, but she got the same treatment as Goneril.
I was writing all relatives of Cordelia Thebe I (Queen Thebe) (Cuz I am doing this for everyone since the family tree is a bit confusing and people might get lost) and it's amazing how we keep saying "in the end the Thebes are just Consort's relatives)
Well no, look how beautiful it is to see this lineage 🥺 The Capps are tied to the Thebes much more than one might think...
This also made me notice that Greta and Jace might know Tyb and Jul & Romeo's kids, how cute (Especially Dante who is a teenager like Greta)
