Explain to me that if genetically we are supposed to be made of the best bits of both parents

[EvangelicalAboutButteredToast]

Then why did my kids inherit my partner’s near sightedness when my vision was perfect until age robbed me of it.

its really odd.

I thought you just got a random selection, not necessarily the best bits??

We're genetically made of random bits from our parents, not the best bits. The best bits thing is over many generations on a population level.

We’re not made of the best parts of our parents, we’re made of random parts of them.

What makes you think we are supposed to be made up of the best bits? We are a random mix.

That's not how genetics work.

You don't get the best bits. Your premise flawed. You get what you get.

Best bits only works at a population level and on issues that affect the ability to mate and the chance to survive to mate. There will always be genetically "inferior" specimens but humans don't mate select based on sightedness

That's not how genetics work. It's random.

GCSE level meiosis here:
www.bbc.co.uk/bitesize/guides/z3qjcj6/revision/3#:~:text=meiosis%20is%20a%20form%20of,sperm%20and%20ova%20in%20humans)

You get what you get.

My mum has webbed toes and my dad has autism.

I got both. And passed them both to DS.

We both have good hair, though.

You get random traits from both parents.

Across huge numbers though, if you get bad traits, you're more likely to die young or not have kids. So over lots and lots of generations, the good traits become common

You seem very confused about genetics, OP. How do you think hereditary diseases happen if only the best bits get passed down?

I can remember being taught at school that we got the best bits. That’s just shit then.

You definitely weren’t thought that you only get the best bits in school.

So every generation is better than the last? So healthier, sportier, happier? Don’t see evidence of this?

You were probably taught that you got the 'dominant' bits. But dominant doesn't mean 'best'.

We display the dominant genes, whilst hiding the recessive crap

Now and again, the recessives shine through - I was the only red head in living memory and the only red head in the family for about thirty years

We inherit random shite from both our parents, the 'best' doesn't get through, just random genes rolling past the finish line

Well that certainly stuck in my head even if it isn’t true.

My father had bad eyesight, my mother excellent eyesight, both me and my sibling got excellent eyesight. Seems very unfair that both kids got their father’s eyesight when mine was there for the DNA matching.

That's chance, it's all based on chance. If you had more kids, some of them would have inherited your eyesight.

Also eyesight isnt just genetics. An increase in screen use is causing an increase in people needing glasses

I'm not sure about unfair as it's just a toss of the coin. It's the reason siblings aren't clones or each other. If we only got the best bits they'd be identical?

You will have been taught about dominate genes which people often refer to as "stronger" so perhaps you assumed that was better but that's not at all how it works.

Over all the years humans have been around, using your eyesight one for example, if only the best was passed on then by now it would be very rare for anyone to have bad eyesight. It would be only those whose ancestors for generations and generations exclusively married fellow bad-eyesight people.

Except we've artificially changed natural selection with things like medical treatment of condtions that once would have killed people, vaccinations so people with weaker immune systems still survive childhood, people having kids who are infertile, PGD of embryos,
benefits that support the sick who may previously have died because they were to sick to work. I fall into the later and have kids. I am glad we have all these things, both on a personal level and on the wider societal one, I think theyre good things, but they do mean natural selection isn't free to work in the human population. It would be interesting to see in 10, 20, 30 thousand years how this has effected human evolution.

Yes, this is true. Though I'm very glad I live in an era where natural selection is somewhat less brutal in human terms.

Yes, you get half your genes from each, but it's random as to which half.

OP - I think you've misunderstood how it all works.

Nope, you don't get the best bits, just random ones.

Everyone has two of each gene, and each parent passes down one of each gene down to their children, at random. So the kids ends up with two sets of each gene from their parents.

Some genes are more dominant than others, so if you get the gene for brown hair from one parent and ginger hair from the other, you'll end up with brown hair, because that's the dominant gene. But neither copy of the gene is "better".

Surely it depends what kind of "bad trait" it is? Not all bad traits will kill you before you're old enough to reproduce. Huntington disease, for example, doesn't show up until middle age.

Sometimes it does work that one parent gives you a faulty copy of a gene, but also having a functioning copy from the other parent means that whatever that genetic disorder might be won’t show in you. Maybe that’s what you interpreted at school as ‘getting the best bits’.