Human population genetics and a Noahic Bottleneck

The genetic evidence shows that during the last 500,000 years human population has never been as low as 2 (going back father, the evidence is weaker but still seems to rule out a single couple). Creationists try get around this by claiming Adam and Eve were created with more genetic diversity than humans are naturally born with. However even if we allow this ad hoc explanation, creationists also believe in a global flood where only 8 people on earth survived, 3 of which had the same parents, so that’s a genetic bottleneck of 5. Creationists can’t claim that those 5 individuals (who lived 10 generations after Adam) had more genetic diversity in the same way they claim Adam and Eve did. I assume that the evidence that rules out a bottleneck of 2 would also rule out a bottleneck of 5, so how exactly would creationists respond to this? I don’t agree with the creationist view at all, but I’m just trying to play devils advocate.

See here: The Misunderstood Science of Genetic Bottlenecks :

RTB used TMR4A and “time to most recent 10 alleles” (TMR10A) to update their model. There were eight people on the Ark: Noah, his wife, his three sons, and their three wives, holding 10 lineages at most.48 Looking across the genome, the median TMR10A is approximately 180,000 years ago. Apart from miraculous intervention or interbreeding between Noah’s lineage and others, the TMR10A rules out a Noahic bottleneck more recent than this time. So RTB places Noah at about 180,000 years ago, and positing that Eve was created as a genetic mosaic, with different genomes in each her eggs, passing on more lineages than needed to account for the LiTI estimates at the origin of our species.

And here: Brief Population Bottlenecks Are Beyond The Genetic Streetlight | Research Square

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Right, so that rules out the date for Noah given by YEC, which is 4,500 years ago.

TMR10A doesn’t prove that the human population really was as low as 8 though does it? Rather it’s more a case of RTB wanting to claim the human population was once as low as 8, and the most recent time that the evidence allows for that possibility was 180,000 years ago. The evidence itself doesn’t imply that there were only 8 people on the earth at that time.

Yes, still seems very ad hoc though. But there again, given that on the RTB model Adam was a special creation that would be a miracle, so its not impossible from a theological perspective. But it’s not exactly scientific.

An easier point about the flood is that it reduces the Y chromosome to a single lineage and the mitochondrial genome to a maximum of three, neither of which is credible.

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I find myself increasingly of the opinion that we should not respond to apologetics arguments as if they were scientific arguments. If they can provide evidence and a hypothesis that does not contradict multiple lines of established science, then we can give it consideration, and not before. If Creationist want to be scientists they should carry the burden of doing the work needed to support those claims, as well as reviewing existing literature to identify contradictions.
Creations draw a lot of attention to themselves by creating false arguments. We need to think less about disproving these claims and more about putting the burden of proof where it belongs.

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I’m of the same inclination. On the other hand, much of the general public assumes that an unanswered argument must mean that the creationist argument must thereby be a valid one. (Yeah, I hate that kind of terrible logic. But that’s how a lot of people think.)

I appreciate the ongoing stream of Gutsick Gibbon videos on Youtube which address the pseudoscience of creationist leaders and organizations with both rigor and good humor. (I regularly download the audio track from her videos so that I can hear them through my bluetooth hearing aids at the gym.***) Is she helping celebrity creationists “draw a lot of attention to themselves”? Perhaps. But I think the educational merits outweigh the free publicity given the YECist P.T. Barnum types like Ken Ham.


*** Yes, the clause “so that I can hear them through my bluetooth hearing aids” is kind of a pathetic admission of advancing age. Meanwhile, I don’t think my hearing aids have helped my listening comprehension all that much (especially in public areas where I was told these devices would excel)—but being always “wired” for lectures and podcasts is pretty nifty. I even use Balabolka to convert web articles and papers to mp3 files because I don’t have time to read them all. Very handy while driving. The downside is that I’m tempted to listen to too much Answers in Genesis drivel—but I happen to enjoy good comedy.

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There is merit to that too, but the effort is enormous. For most encounters I think we might get by with, "Hey Dude, that’s apologetics, not science. You must know the difference, right?"

I’m going to put this to the test at the next opportunity, and start keeping track of responses. This isn’t so different from my usual approach, but it is more direct to the point.

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I beg to differ. There is nothing ad hoc or unscientific about it at all. If there is a universal common designer such as Jesus, we would expect humans to possess cognitive qualities that are exceptions to what would otherwise be predicted if we were evolutionary descendants.

Thanks for the comment, but what has it got to do with the topic under discussion? I was talking about genetic variation and the claim that Eve was created as a genetic mosaic, with different genomes in each her eggs. How is that not ad hoc?

Anyway, I think it’s perfectly reasonable to think that cognitive abilities like ours (which are often pretty good, but seem to be very easily prone to error as well) could arise though evolution.

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Best not to let him take over another thread.

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Noah at 180,000 years ago rules out boats!

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