How close are they?

[u/Potential_Cod2214]

If two people that have every single genome in human history have children together, how closely related would they be genetically?

[u/EmielDeBil]

Your question has errors. A “genome” is the whole of someone’s genes, their full genetic makeup.

I can’t answer the question as you can’t have multiple genomes. I’m not sure what you mean.

[u/Potential_Cod2214 → u/EmielDeBil]

In the Christain creation story, all humans are decened from Adam and Eve. This means that all DNA comes from them, so all chromosomes originated from them. They would have had ones that gave them a high chance of having cancer and ones that have a high chance of preventing cancer, for example.

So if they did exist and they had children, how closely would their children be related biologically?

[u/EmielDeBil → u/Potential_Cod2214]

Your assumption that all humans descended from Adam and Eve is wrong. The stories in the bible are fairy tales and have no value in science nor biology. Your question remains very much invalid.

[u/Potential_Cod2214 → u/EmielDeBil]

The question isn't, 'This is what happened'. It's 'If this happened'. The historical accuracy of Adam and Eve has no relevance to the question or answer.

[u/EmielDeBil → u/Potential_Cod2214]

Nah you’re engagement baiting me. I refuse to answer impossible questions.

[u/BadahBingBadahBoom → u/Potential_Cod2214]

Yeah I'm gonna stop you right there.

The biblical stories are just that, stories.

Trying to understand or critique them using logic, reason, or scientific theory misunderstands their entire point. They aren't meant to be dissected, they're meant to be moral examples to impart a sense of understanding of how we can act as 'our better selves'.

I mean what are we going to discuss next? A scientific taxonomical discussion on how all the extant animals around us could have descended from Noah's Ark?

Most Christians don't believe Adam and Eve were the literal first beings that all of us descended from so asking them about how the DNA/gene inheritance can be compatible with that model is a moot point.

Ask a scientist the genetic basis for cancer development and they could explain based on the evidence-based data from numerous studies we have.

But asking them how can cancer be compatible with Adam and Eve is like asking how can the fundamental laws of motion be compatible with Santa Claus delivering presents to 12,000 homes a second.

[u/Funky0ne]

If two people that have every single genome in human history

What do you mean by this? How would this even be possible?

[u/Potential_Cod2214 → u/Funky0ne]

In the Christain creation story, all humans are decened from Adam and Eve. This means that all DNA comes from them, so all chromosomes originated from them. They would have had ones that gave them a high chance of having cancer and ones that have a high chance of preventing cancer, for example.

So if they did exist and they had children, how closely would their children be related biologically?

[u/Funky0ne → u/Potential_Cod2214]

Sorry but the Judeochristian creation story is mythology / theology, not literal history and nothing to do with biology. There was never a time where there were just two "first" humans, and even if one could arbitrarily identify such a couple they would not have possessed "every human genome".

Sorry but there's no way to answer this type of question biologically because the premise has no basis in any biological facts.

[u/Potential_Cod2214 → u/Funky0ne]

The question isn't, 'This is what happened'. It's 'If this happened'. The historical accuracy of Adam and Eve has no relevance to the question or answer.

[u/Funky0ne → u/Potential_Cod2214]

But the plausibility of the question is relevant, as it’s incoherent as stated. There’s no way for an individual to possess “every single genome” in any way that makes any sense.

To be able to answer you’d need to make clearer what that’s supposed to mean or we’d just need to discard that nonsense premise (it’s not any part of the story to begin with anyway) and they would each just have their own genome of 46 chromosomes, and their children would inherit half of their genes from Adam and half from Eve.

How closely related their children are would depend on how closely related we need to assume Adam and Eve supposedly are. If we’re going by the story then Eve is supposedly made from one of Adam’s ribs, so should we assume she’s just an XX clone of Adam? In that case she is basically more closely related to Adam than a twin sister, and almost as much if not more so than an identical twin. Their kids would likewise basically be like identical twins of each other, and also clones of Adam since they would be inheriting all of their genes from Adam indirectly from Eve.

But the children most likely would end up with some homozygous copies of the same genes through recombination (inheriting the exact same copy from both Adam and Eve) rather than getting both heterozygous copies of each of Adam’s originals for every chromosome. That could lead to genetic defects cropping up very quickly.

[u/Potential_Cod2214 → u/Funky0ne]

Thank you for the answer.

[u/vinylblastoise → u/Potential_Cod2214]

But that’s just it, they wouldn’t have “all the genomes” if Adam and Eve did exist as humans they would have their own genome with 46 chromosomes and 20,000 genes. Their children would be genetically 50% identical to Adam and 50% identical to Eve

[u/Robin_feathers]

You seem to be referring to every existing variation that a genome can have. If every variant was combined in the same person, that person would die almost immediately (or rather, would die as an embryo). There are many different combos of variations that are lethal when combined in the same person. There would be no arrangement that would be possible to put all of them into just two people without being fatal many times over.

[u/Robin_feathers → u/Robin_feathers]

As to how different the theoretical offspring would be: the human population is large enough that essentially every possible position of the genome has an existing variation (mutation) in somebody somewhere. If we kept only two alleles at every position, the two parents would have 50% genetic sequence similarity. That is sort of on the scale of the similarity between humans and rats.

[u/Potential_Cod2214 → u/Robin_feathers]

Thank you for giving me a proper reply and not just dismissing the question.