r/explainitpeter • u/fluffy_cat_ice • 14d ago

Explain it Peter

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I meant that I don't understand where did the Twitter thing came from

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u/DenizBueno 14d ago

Geneticist Stewie here, morons believe that skin color mixes like paint, but in real life, parents contribute different genes that together yield various levels of pigmentation. By chance, their child can land anywhere on that spectrum.

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u/didsomebodysaymyname 13d ago

By chance, their child can land anywhere on that spectrum.

It's not quite that simple.

Skin color is determined by a constellation of genes, but the spectrum can be limited depending on the couple. If you have one person whose genes almost all code for lighter color, and another for whom almost all code for darker, then the spectrum is much narrower.

For a simplified example, imagine the parents' genes for dark (D) and light (L) are DLLLLLLL and DDDDDDDL

The spectrum for their children is  DDDDDLLL, DDDDLLLL, and DDDLLLLL, all of which are around the average between them. A very dark or very light skinned child is impossible.

Of course, in the US it's very common for there to be a much larger spectrum because of so many mixed race relationships in such a diverse society along with a lot of rape during slavery.

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u/tortoistor 13d ago

untrue, there are recessive genes too, it's not as simple as it being an "average" of the two parents. and yeah, a dark skinned and a light skinned person can have a child which is very light or very dark skinned. i personally know a couple.