Just to be well and truly fuckin clear. I am not now nor have I ever been nor will I ever be contemplating shagging a family member.
Just to be well and truly fuckin clear. I am not now nor have I ever been nor will I ever be contemplating shagging a family member.
Human genes only really “work as intended” when they are combined from very different sets.
So-called “recessive” genes are overruled by your partner’s different pile of genes. They are usually shit traits like soggy bones or hair growing backwards, but since they never dominate, they haven’t been naturally selected away. They’re just harmless baggage.
You can still get them because it’s all random, but the likelihood is generally low.
If you don’t have that difference in mating genes, more of these recessive genes get to have a say in building the human. This severely increases the likelihood of birth defects.
https://en.wikipedia.org/wiki/Inbreeding
Fun fact: This is one of the reasons why - when we start colonies on the Moon or Mars or wherever - it’s important that we send a fuck ton of people.
Well, there’s a new insult: “You soggy-bones looking mother fucker.”
Ok, but why are recessive genes necessarily bad?
Or, they probably aren’t, but it turns out when you activate them you get more bads than the goods. Why is that?
Good question!
They aren’t necessarily bad as such, just “random and unfiltered”.
Dominant genes get “battle tested” all the time, by definition. The harmful ones are likely to result in a human that can’t survive or have children, while the good ones remain.
Recessive isn’t always bad. In fact, many (maybe all) genetic traits have a dominant and a recessive information.
For example peas. Let’s say there is a gene for colour. The dominant variation of the colour gene carries the information “green”. Let’s call this gene c for colour. Then there is a recessive variation with the information yellow.
We’ll write the dominant information as capital C and the recessive as lowercase c.
Now there is a pea with the genetic information CC (one from each parent). That’s a green pea.
Then there is one with Cc (father green, mother yellow). But you see the pea and it looks just like a green pea. Because the green gene C is dominant and the yellow c is recessive. You don’t know, that this is a mixed variety.
If two seemingly green peas pollinate each other, but under the hood, they are Cc, then they might produce a cc yellow pea.
For a lot of genetic information that’s not a problem, they are just different characteristics and not harmful.
But if you have B = your blood coagulates normally, and b = your blood doesn’t thicken, you just bleed out and die when you have a paper cut…
Then inheriting b from both of your parents is a terrible fate.
This happened in the House of Saxe-Cobourg and other nobility in the 19th century.Edit: the last part is actually a bit more complicated, but the explanation of dominant and recessive still works.