The Incest Problem

[Elixir]

I have yet to see any explanation for The Incest Problem.
Handwaving attempts do abound, but none of them actually addresses the fact that if A&E were the only two humans and all extant humans are their descendants, there was massive incest happening in the first few generations of humans.

Is there ANY explanation that relies on facts? AFAIK, everything offered thus far starts with a "perhaps" and has no supporting facts to support the "perhaps" offering.

 

[Rhea]

Ditto the 3 siblings in the Noah story. It is not possible to populate the earth from 3 mating pairs - who are siblings - without incest.

Not possible.

 

[excreationist]

I have yet to see any explanation for The Incest Problem.....

Well see this:

https://askjohnmackay.com/how-did-t...if-god-doesnt-allow-brother-sister-marriages/
https://creation.com/incest-noah-family
https://creation.com/cains-wife-brother-sister-intermarriage
https://answersingenesis.org/bible-characters/cain/who-was-cains-wife/

Do you even know why incest if bad? It is because close relatives are more likely to have mutations in common. Mutations accumulate. I think it makes sense for Adam and Eve to have had zero mutations originally. In the laws supposedly given to Moses, God outlaws incest perhaps because a lot of mutations had accumulated. There was no mention of incest being outlawed before that.

I'm not saying those arguments are flawless but they could be called "explanations". (which you say you can't see any)

 

[T.G.G. Moogly]

I think it makes sense for Adam and Eve to have had zero mutations originally. In the laws supposedly given to Moses, God outlaws incest perhaps because a lot of mutations had accumulated. There was no mention of incest being outlawed before that.

So your answer is to ignore facts and rely on magic? The OP asked for factual responses. Even if A&E were not mutated they became mutated after they ate the apple. So they were mutated when they had offspring, and their offspring's offspring were therefore inbred mutants.

They didn't have any offspring in the magic garden. If they had then none of their offspring would be inbred mutants owing to the fact that the garden was magic. But magic isn't factual.

 

[Lion IRC]

I have yet to see any explanation for The Incest Problem...

What's the "Incest Problem"?
https://theconversation.com/incest-isnt-a-taboo-in-the-animal-kingdom-new-study-160937

 

[excreationist]

I think it makes sense for Adam and Eve to have had zero mutations originally. In the laws supposedly given to Moses, God outlaws incest perhaps because a lot of mutations had accumulated. There was no mention of incest being outlawed before that.

So your answer is to ignore facts and rely on magic?

https://www.nature.com/articles/news.2009.864
"....Every time human DNA is passed from one generation to the next it accumulates 100–200 new mutations..."

Are you saying accumulating mutations is "magic"? Or is it "magic" for Adam and Eve to originally have no mutations?

The OP asked for factual responses

Yeah it said

".....Is there ANY explanation that relies on facts? AFAIK, everything offered thus far starts with a "perhaps" and has no supporting facts to support the "perhaps" offering...."

I don't remember that part of the post being there originally or maybe I didn't notice it... but anyway it is a fact that mutations accumulate and that the problem with incest is to do with having mutations in common....

Even if A&E were not mutated they became mutated after they ate the apple.

That previous link says that mutations accumulate when DNA is passed on from one generation to the next. (not that mutations could spontaneously affect an entire fully grown person) Even if it did affect Adam and Eve as soon as the fall happened they would have independent different mutations and so not have the incest problem where the parents have mutations in common...

So they were mutated when they had offspring, and their offspring's offspring were therefore inbred mutants.

But there is a difference between one generation of mutations and dozens....

They didn't have any offspring in the magic garden. If they had then none of their offspring would be inbred mutants owing to the fact that the garden was magic. But magic isn't factual.

It is possible that the mechanism that accumulates mutations at 100-200 more per generation could be reduced or non-existent.

 

[excreationist]

....Is there ANY explanation that relies on facts? AFAIK, everything offered thus far starts with a "perhaps" and has no supporting facts to support the "perhaps" offering.

It is a fact that mutations accumulate:
https://www.nature.com/articles/news.2009.864
"....Every time human DNA is passed from one generation to the next it accumulates 100–200 new mutations..."

It is a fact that mutations can be caused by ultraviolet radiation so it seems that less of that would result in less mutations.

It is a fact that the problem with incest has to do mutations - that close relatives are likely to have mutations in common.

When non-closely related people with mutations produce offspring the non-mutated genes can be used but if both are mutated then it can't use a good version.

It is a fact that the Bible has no problem with incest until Moses' time and an explanation for this is that it took a while for mutations to accumulate and become a problem with close relatives.

 

[T.G.G. Moogly]

Are you saying accumulating mutations is "magic"? Or is it "magic" for Adam and Eve to originally have no mutations?

A&E are mythical, magical characters in a creation story. So, yes, for purposes of this discussion they had none of the human characteristics with regard to scientific knowledge that we have today. It's a story about how a culture came to be, how the gods made "us" for a particular group. It's pretty common stuff.

Given the knowledge we own today, the OP is asking how this particular creation myth can be possible. Your response seems to be that these two blokes were created magically, free of human frailty, then were cursed. So, your story posits magic creatures from magic creatures that begat all of us via subsequent inbreeding. If they were mutation free then they were mutation free by magic. That's not factual.

Your entire offering is based on magic.

 

[Elixir]

....Is there ANY explanation that relies on facts? AFAIK, everything offered thus far starts with a "perhaps" and has no supporting facts to support the "perhaps" offering.

It is a fact that mutations accumulate:
https://www.nature.com/articles/news.2009.864
"....Every time human DNA is passed from one generation to the next it accumulates 100–200 new mutations..."

It is a fact that mutations can be caused by ultraviolet radiation so it seems that less of that would result in less mutations.

*facepalm*

* Not all mutations accumulate. Many are lethal, most do nothing and are not carried forward as dominant.
* UV radiation is far from the only - or even the major cause of mutations.
* Incest is no longer a major contributor to population-wide mutations.
* Mutations only persist and proliferate within a population if they confer a reproductive advantage or are neutral in effect. They don't all accumulate like dust bunnies in the corner of your laundry room.

When non-closely related people with mutations produce offspring the non-mutated genes can be used but if both are mutated then it can't use a good version.

What the hell is this "it" you're talking about that "can't use"? Sounds like anthopomorphizing. Evolution doesn't have direction or goals.

It is a fact that the Bible has no problem with incest

Yeah, that's the weird thing. Incest would have been a problem within a generation or two, REGARDLESS of the genetic makeup of the first inbreeding pair. As TGG points out, you are positing that A&E not only existed, but existed due to Ye Olde Majicke.
Sorry, that's neither fact-based nor an explanation.

an explanation for this is that it took a while for mutations to accumulate

Uh ... no. That's not an explanation, it's another ignorance-based "perhapsism" like "Perhaps volcanoes blasted koalas to Australia after De Fludde."

 

[Rhea]

Uh ... no. That's not an explanation, it's another ignorance-based "perhapsism" like "Perhaps volcanoes blasted koalas to Australia after De Fludde."

You know, this reminds me that the problem of incest is not unique to humans in this story.

Rather, every single species on the planet would have had to repopulate from a single breeding pair, necessitating incest for generations in every single genetic line. They would not have survived. We already know how hard it is to aintain species when they are down to a few hundred breeding pairs. But one? for every species?

Storyline fail.

 

[Angra Mainyu]

I have yet to see any explanation for The Incest Problem...

What's the "Incest Problem"?
https://theconversation.com/incest-isnt-a-taboo-in-the-animal-kingdom-new-study-160937

The problem would be an internal problem, given Christianity's stance against incest.

But that aside, you are mistaken. Whether it is a problem depends on the species. For example, human seem to have a tendency to avoid inbreeding. And they are animals. Also, for instance, grey wolves seem to have that tendency (e.g., https://pubs.er.usgs.gov/publication/5223836 ), chimpanzees ( https://www.sciencedirect.com/science/article/abs/pii/S0003347280800637 ), mountain gorillas ( https://gorillafund.org/uncategorized/do-mountain-gorillas-avoid-inbreeding/ ), capuchin monkeys ( https://www.eurekalert.org/pub_releases/2006-03/cp-aia030106.php) among others. Even if some animals don't do that, you can easily find a good number that do. Inbreeding avoidance seems common in monkeys like us (or if you use different terminology, in monkeys and apes like us).

 

[Rhea]

I have yet to see any explanation for The Incest Problem...

What's the "Incest Problem"?
https://theconversation.com/incest-isnt-a-taboo-in-the-animal-kingdom-new-study-160937

The problem would be an internal problem, given Christianity's stance against incest.

But that aside, you are mistaken. Whether it is a problem depends on the species. For example, human seem to have a tendency to avoid inbreeding. And they are animals. Also, for instance, grey wolves seem to have that tendency (e.g., https://pubs.er.usgs.gov/publication/5223836 ), chimpanzees ( https://www.sciencedirect.com/science/article/abs/pii/S0003347280800637 ), mountain gorillas ( https://gorillafund.org/uncategorized/do-mountain-gorillas-avoid-inbreeding/ ), capuchin monkeys ( https://www.eurekalert.org/pub_releases/2006-03/cp-aia030106.php) among others. Even if some animals don't do that, you can easily find a good number that do. Inbreeding avoidance seems common in monkeys like us (or if you use different terminology, in monkeys and apes like us).

But how would any of those - including humans - have avoided that in the creation story or post flood?
In both cases, there were too few mating pairs to avoid incest and still maintain the story of multipying populations.

 

[bilby]

WTF would "without mutations" even mean, in the bizarre nonsense phrase "Adam and Eve were created without mutations"?

Doesn't anyone in this thread know what a genetic mutation is? Or have the first inkling what the human genome looks like? Or how nucleic acid base sequences cause the formation of proteins?

A mutation (in molecular biology) isn't a flaw, or an error, or a defect. It's just a difference.

To say "Adam has no mutations" is as coherent as saying "there's no difference between this tree".

It's not clear to me at all, that it would be coherent to assert that a person is without any genetic flaws. But even if it were, it's certainly not coherent to assert that a single individual is without differences.

Whether a given mutation is harmful or beneficial is a situational and relative question. There are no harmful mutations, only mutations that are harmful for a particular species in a particular environment. Incest is problematic because it reduces genetic diversity at the level of the individual, and diversity at that level is beneficial because it provides multiple options when dealing with an environmental characteristic.

How beneficial diversity is, depends both on the other biochemical options within the organism, and on the environment in which it lives.

Before genetics was well understood, there were many attempts to achieve some kind of 'purity' amongst privileged classes of humans. The Ancient Egyptian royals, and the Medieval European ones, encouraged incest as a means of keeping the royal 'blood' pure. These attempts failed not because they didn't achieve that objective, but because the people doing it had no understanding that the objective itself is disastrous. They succeeded so well that the success crippled them.

If, by "without mutation", we are seeking to imply that every gene in every one of Adam's cells was identical to every other instance of that gene (including the complementary copy on the other member of each chromosome pair), then that implies two things: Adam (and any of his descendants) would have been hugely vulnerable to the slightest variation in his environment (for example, to any changes in the bacteria with which he coexisted - bearing in mind that a sizeable fraction of the living cells in a healthy human being are non-human cells), and as a result would have lived a short, disease wracked life; And perhaps even more problematic, Adam and all of his descendants would have been female.

The whole basis for this discussion is a counterfactual set of assumptions about purity and genetics that were very popular in the pre-enlightenment era, but are now known to be completely wrong.

That's not how it works. That's not how any of it works. You cannot breed a successful population of primates, or indeed of almost any mammals, from a population of a few dozen individuals or fewer, because there simply isn't sufficient diversity in such a population for it to handle the unavoidable variability of its environment. And decreasing diversity still further (which is what reducing the number of mutations means) would be making the problem worse, not better.

 

[Bomb#20]

WTF would "without mutations" even mean, in the bizarre nonsense phrase "Adam and Eve were created without mutations"?

Doesn't anyone in this thread know what a genetic mutation is? Or have the first inkling what the human genome looks like? Or how nucleic acid base sequences cause the formation of proteins?

A mutation (in molecular biology) isn't a flaw, or an error, or a defect. It's just a difference.

To say "Adam has no mutations" is as coherent as saying "there's no difference between this tree".

You have to be prepared to do a certain amount of translation of terminology if you want to understand the great unwashed when they're trying to express themselves about technical subjects. I think what the people misusing the word "mutation" mean by it is roughly "deleterious recessive allele".

 

[Bomb#20]

You know, this reminds me that the problem of incest is not unique to humans in this story.

Rather, every single species on the planet would have had to repopulate from a single breeding pair, necessitating incest for generations in every single genetic line. They would not have survived. We already know how hard it is to aintain species when they are down to a few hundred breeding pairs. But one? for every species?

Storyline fail.

Sometimes they survive. There are lineages that can only plausibly be on some continent because millions of years ago one pregnant female got washed out to sea on some floating vegetation from the continent where she was born, and when she arrived in a new land her litter bred with one another.

The real storyline fail doesn't depend on hypotheticals about who would have survived if such and such had happened. We can tell by inspection that the human ancestor population was never as low as one breeding pair. If there had ever been a real Adam and Eve, they plainly can't have had among them more than four versions of any one gene. There are lots of genes in the human genome for which the current population has more than four variants -- sometimes a lot more. The genes for the immune system are especially prone to this since variation is such a good way to improve someone's chances of surviving an epidemic.

A biblical literalist would have to argue that we started with only four and the extras arose by mutation since Adam and Eve's time. But that's a falsifiable theory. Highly variable genes also occur in other monkey species. There are immune system genes where not only do humans have a dozen variants, but rhesus monkeys also have a dozen variants of the same gene -- and they're the same dozen variants. Version X of human gene G is more closely related to version X of rhesus monkey gene G than it is to version Y of human gene G. If all those variants had arisen by random mutation independently in humans and rhesus monkeys, then humans would have different variants from the variants in monkeys.

 

[bilby]

You know, this reminds me that the problem of incest is not unique to humans in this story.

Rather, every single species on the planet would have had to repopulate from a single breeding pair, necessitating incest for generations in every single genetic line. They would not have survived. We already know how hard it is to aintain species when they are down to a few hundred breeding pairs. But one? for every species?

Storyline fail.

Sometimes they survive. There are lineages that can only plausibly be on some continent because millions of years ago one pregnant female got washed out to sea on some floating vegetation from the continent where she was born, and when she arrived in a new land her litter bred with one another.

I am skeptical of this. I suspect that such isolated lineages would have required at least occasional innoculation by a repeat of the same or similar processes; ie an initial isolated population formed as you describe would, affer a handful of generations, see a new individual arrive via the same mechanism, bringing an injection of diversity to the gene pool, leading to a viable isolated population with a larger number of ancestors than just two (and bear in mind that some mammals can bear single litters wherein the young have different fathers, providing a further source of diversity).

It seems to me implausible that a single ancestor could make such an unlikely journey, without that unlikely journey being repeatable at least every few years or decades. Though I wouldn't rule it out, I would like to see some very solid evidence in the genome of such a population before I would be convinced.

The real storyline fail doesn't depend on hypotheticals about who would have survived if such and such had happened. We can tell by inspection that the human ancestor population was never as low as one breeding pair. If there had ever been a real Adam and Eve, they plainly can't have had among them more than four versions of any one gene. There are lots of genes in the human genome for which the current population has more than four variants -- sometimes a lot more. The genes for the immune system are especially prone to this since variation is such a good way to improve someone's chances of surviving an epidemic.

A biblical literalist would have to argue that we started with only four and the extras arose by mutation since Adam and Eve's time. But that's a falsifiable theory. Highly variable genes also occur in other monkey species. There are immune system genes where not only do humans have a dozen variants, but rhesus monkeys also have a dozen variants of the same gene -- and they're the same dozen variants. Version X of human gene G is more closely related to version X of rhesus monkey gene G than it is to version Y of human gene G. If all those variants had arisen by random mutation independently in humans and rhesus monkeys, then humans would have different variants from the variants in monkeys.

This, however is clearly solid. The evidence here is overwhelmingly good in showing both that neither humans nor rhesus monkeys have experienced a bottleneck of just a handful of closely related individuals; and that the two species share a common ancestor in fairly recent evolutionary history.

 

[excreationist]

....You have to be prepared to do a certain amount of translation of terminology if you want to understand the great unwashed when they're trying to express themselves about technical subjects. I think what the people misusing the word "mutation" mean by it is roughly "deleterious recessive allele".

Yes that is exactly what I mean....

 

[excreationist]

*facepalm*

* Not all mutations accumulate. Many are lethal, most do nothing and are not carried forward as dominant.

In my quote it said that that "100–200 new mutations" accumulate. I didn't mean to say that they are the only mutations that are ever involved.

* UV radiation is far from the only - or even the major cause of mutations.

I said they "can be" caused by UV radiation.

* Incest is no longer a major contributor to population-wide mutations.

I said "It is a fact that the problem with incest has to do mutations". I didn't talk about how common it is now as far as mutations go.

* Mutations only persist and proliferate within a population if they confer a reproductive advantage or are neutral in effect.

You said "only".... what about "genetic conditions".... are they neutral in effect?

They don't all accumulate like dust bunnies in the corner of your laundry room.

The YEC argument doesn't require every single mutation to accumulate in order for this to be a problem.

When non-closely related people with mutations produce offspring the non-mutated genes can be used but if both are mutated then it can't use a good version.

What the hell is this "it" you're talking about that "can't use"? Sounds like anthopomorphizing. Evolution doesn't have direction or goals.

Like Bomb#20 wrote:

I think what the people misusing the word "mutation" mean by it is roughly "deleterious recessive allele".
​

So if there is "good version" it can be dominant and suppress the problematic mutated allele.

It is a fact that the Bible has no problem with incest [you removed "until Moses' time"]

Yeah, that's the weird thing. Incest would have been a problem within a generation or two, REGARDLESS of the genetic makeup of the first inbreeding pair.

No I think incest is a problem when there are identical deleterious recessive alleles. And this is more likely to be a problem if 2000 mutations have accumulated compared to 100-200.

As TGG points out, you are positing that A&E not only existed, but existed due to Ye Olde Majicke.

It is possible to originally lack deleterious recessive alleles. Also I am just talking hypothetically about Adam and Eve.

an explanation for this is that it took a while for mutations to accumulate

Uh ... no. That's not an explanation, it's another ignorance-based "perhapsism" like "Perhaps volcanoes blasted koalas to Australia after De Fludde."

I think detectives who talk about "perhaps" can be considered to have explanations.

 

[excreationist]

I have yet to see any explanation for The Incest Problem.....

https://www.lic.co.nz/products-and-services/artificial-breeding/inbreeding-and-recessive-genes/

Inbreeding [incest] also increases the risk of disorders caused by recessive genes. These disorders can lead to calf abnormalities, miscarriages and stillbirths.

​

Animals must have two copies of a recessive gene to have the disorder. They receive one copy of the gene from each parent.

​

Animals that are closely related are more likely to carry a copy of the same recessive gene. This increases the risk they will both pass a copy of the gene onto their offspring.
​

Like me and Bomb#20 were talking about, it is about deleterious recessive alleles.... as far as likelihood goes in the quote, it is more likely to be a problem if many mutations have accumulated over many generations than if it only one generation worth of mutations have accumulated.

So "deleterious" means involving disorders such as abnormalities, miscarriages and stillbirths. The first sentence confirms that this is about recessive genes. And alleles is perhaps a more specific term than "genes".

I think an absence of these recessive problematic alleles could be possible in Adam and Eve..... I mean it is even possible for some scientists to do - they can remove or at least detect problematic alleles like genetic conditions....

 

[bilby]

I have yet to see any explanation for The Incest Problem.....

https://www.lic.co.nz/products-and-services/artificial-breeding/inbreeding-and-recessive-genes/

Inbreeding [incest] also increases the risk of disorders caused by recessive genes. These disorders can lead to calf abnormalities, miscarriages and stillbirths.

​

Animals must have two copies of a recessive gene to have the disorder. They receive one copy of the gene from each parent.

​

Animals that are closely related are more likely to carry a copy of the same recessive gene. This increases the risk they will both pass a copy of the gene onto their offspring.
​

Like me and Bomb#20 were talking about, it is about deleterious recessive alleles.... as far as likelihood goes in the quote, it is more likely to be a problem if many mutations have accumulated over many generations than if it only one generation worth of mutations have accumulated.

So "deleterious" means involving disorders such as abnormalities, miscarriages and stillbirths. The first sentence confirms that this is about recessive genes. And alleles is perhaps a more specific term than "genes".

But 'deleterious' is contextual. The popular understanding of genetics as described by Mendel is a massive oversimplification, which can be a good starting point for understanding what is going on, but which is a poor model of the vast majority of real genetics. Few phenotypic traits are controlled by single genes, and molecular biology has shown us why things are far more complex than Mendel suggests.

To give one well known example of contextual deleteriousness, the genetic disorder 'Sickle Cell Anaemia' is due to a recessive gene, and (as we might expect), people with two copies of that gene are frequently very unwell. But (more unexpectedly) having only one copy gives people protection against Malaria. So the absence of the gene is deleterious in environments where Malaria is endemic.

At the molecular level, classical 'recessive' traits typically imply the inability to make a particular protein, while dominant traits imply the ability to make that protein. But the proteome is itself hugely complex, and it's fairly unusual for phenotypic effects to be mediated by just one gene, because there are often multiple biochemical pathways to a given phenotypical result.

There are almost no statements about biochemistry or genetics that cannot be rendered more accurate by adding "...but in reality it's far more complicated than that". This is even true of the statement "biochemistry and genetics are far more complex than we can really grasp".