# Is RTBs Model Sole Progenitor?

**URL:** <https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989>\
**Category:** Conversation\
**Created:** [July 19, 2021, 7:40pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989 "2021-07-19T19:40:14Z")\
**Posts on this page:** 20\
**Page:** 1

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 19, 2021, 7:40pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/1 "2021-07-19T19:40:14Z")

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Where is the current RTB model articulated?

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 19, 2021, 7:40pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/2 "2021-07-19T19:40:36Z")

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Out of scope on this thread. We’ll address it another day. I promise.

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**Author:** ![Robert\_West](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/robert_west/32/8509_2.png) [@Robert\_West](https://discourse.peacefulscience.org/u/Robert_West)\
**Post date:** [July 19, 2021, 7:54pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/3 "2021-07-19T19:54:54Z")

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Agree, what you’ve written is entirely appropriate. Were it not for the fact that BioLogos is a “Christian advocacy group” founded by Francis Collins, I might have said just forget about it. But what they’ve done is straightforwardly unethical, and undermines their credentials from the standpoint of faith as well as science. It must be called out.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 19, 2021, 7:55pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/4 "2021-07-19T19:55:05Z")

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It’s hardly out of scope since you brought it up. If RTB’s model tolerates a bottleneck of 2, even without requiring one, then it’s incompatible with the cross-species polymorphism evidence.

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 19, 2021, 8:15pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/5 "2021-07-19T20:15:02Z")

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Their proposal is pretty simple, actually:

1. AE live about 185 kya, and there is a Noahic bottleneck at about 180 kya.

2. Eve has a different genome in each egg (perhaps even pull from the surrounding population at her creation).

3. At any point along this scenario interbreeding with other populations of hominins is possible. They officially believe Neanderthals did not arise before Adam and Eve, but have no reason to exclude other sorts of interbreeding.

4. AE are our sole-genetic progenitors. They mean, by this term, that all the DNA that makes us fully human we receive by direct genetic descent from them. This a “unique” position that they “soley” hold.

If #4 sounds strange, it shouldn’t. That is how almost everyone in the conversation, it turns out, has understood sole-genetic progenitorship. The idea that sole-genetic progenitorship rules out interbreeding (#3) is a use of the term is highly idiosyncratic.

It should be pretty obvious that there is no strong evidence against this position. To the point, this scenario does not require a genetic bottleneck of 4 alleles.

Is it “plausible”? That is fudge term. I can certainly sympathize with the sentiment that this does not seem theologically necessary or plausible in some subjective senses. But this is an article about scientific evidence, and what is and is not compatible with the evidence. Shifting the terms of the debate away form the genetic evidence is not fair play.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 19, 2021, 9:02pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/6 "2021-07-19T21:02:52Z")

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> [@swamidass](#):
>
> If #4 sounds strange, it shouldn’t. That is how almost everyone in the conversation, it turns out, has understood sole-genetic progenitorship. The idea that sole-genetic progenitorship rules out interbreeding (#3) is a use of the term is highly idiosyncratic.

Agree to disagree. “Sole” is a word that has a meaning, and so is “genetic”. This understanding does violence to both meanings.

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 19, 2021, 9:05pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/7 "2021-07-19T21:05:26Z")

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That’s not the issue.

The point is that people will point to evidence against sole-progenitor (by your definition) as demonstrating sole-progenitor (by their definition) is false.

Disagree with them if you like, but still engage what they are saying appropriately.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 19, 2021, 9:35pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/8 "2021-07-19T21:35:01Z")

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OK, I have to ask who is it using “sole-genetic progenitor” in this odd, counter-intuitive, and nevertheless vague sense?

And does it not require that you inherit considerable genetic material from A&E? If that doesn’t arise from a bottleneck of two, then how else could it happen? Strong selection, perhaps? Or a miracle? I don’t see a fourth option.

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 19, 2021, 10:14pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/9 "2021-07-19T22:14:30Z")

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Reasons To Believe and Ann Gauger are using it this way. That’s two independent groups.

Disagree with it if you must, but it’s just a fact.

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**Author:** ![Dan\_Eastwood](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/dan_eastwood/32/2368_2.png) [@Dan\_Eastwood](https://discourse.peacefulscience.org/u/Dan_Eastwood)\
**Post date:** [July 19, 2021, 10:17pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/10 "2021-07-19T22:17:39Z")

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Welcome to the mosh pit, @Robert_West! 🙂

For those who don’t know, Robert is one of the moderators from the FB group.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 19, 2021, 11:32pm UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/11 "2021-07-19T23:32:07Z")

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> [@swamidass](#):
>
> Reasons To Believe and Ann Gauger are using it this way.

Hate to belabor this, but the definition is still quite vague. Are RTB and Gauger using it in exactly the same way? Do they each have the same understanding of “all the DNA that makes us human”? And either way, what is that understanding?

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**Author:** ![deuteroKJ](https://avatars.discourse-cdn.com/v4/letter/d/46a35a/32.png) [@deuteroKJ](https://discourse.peacefulscience.org/u/deuteroKJ)\
**Post date:** [July 20, 2021, 1:43am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/12 "2021-07-20T01:43:47Z")

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> [@swamidass](#):
>
> - Noahic bottleneck at about 180 kya.

Is this a recent change? I thought it was closer to 70kya in their model, but it’s been a while since I’ve looked at it. (I know this is tangential to the thread.)

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 20, 2021, 1:45am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/13 "2021-07-20T01:45:02Z")

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Early 2020, about the time of our workshop with them. AJ laid it out in a series of 3 or 4 articles.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 20, 2021, 2:02am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/14 "2021-07-20T02:02:35Z")

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Would you be so kind as to provide references when you mention things?

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 20, 2021, 2:03am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/15 "2021-07-20T02:03:10Z")

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I’ll have to look that up later. We discussed them when it came out. They call it “Mosaic Eve”

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 20, 2021, 2:19am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/16 "2021-07-20T02:19:32Z")

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This?:

> [@Mosaic Eve: Mother of All (Part 1)](https://discourse.peacefulscience.org/t/mosaic-eve-mother-of-all-part-1/9338):
>
> One of the big revelations of the RTB-PS workshop on human origins was @AJRoberts’s speculation on “mosaic eve.” Of course, this has an interesting history in the conversation, tracing some history back to Jerry Coyne ([Jerry Coyne's Adam and Eve Contest](https://discourse.peacefulscience.org/t/jerry-coynes-adam-and-eve-contest/4207)). Thanks @Andrew_Loke, @NLENTS and @glipsnort for participating in the workshop. I wonder what you make of it. Starting from our first principles, we set presuppositions about human population genetics that may be tested for consistency with evidence within scientific analyses, including population genetics. In my previous blog, I referenced [a presentation by S. Joshua Swamidass](https://vimeo.com/379301717/46a832ecc8?utm_campaign=2470763&utm_source=affiliate&utm_channel=affiliate&cjevent=257f99672fec11ea802502170a1c0e0b) that helped clarify how others have misrepresented the human population genetics data in order to rule out the possibility of a sole progenitor pair. In scientific terms, they have ruled out a population bottleneck (of two) prior to roughly 500 kya. Another paper (published the same day as Swamidass’s presentation) by Ola Hössjer and Ann Gauger draws parall…

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 20, 2021, 2:45am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/17 "2021-07-20T02:45:35Z")

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And here again:

> [@](#):
>
> 1. The RTB sole-progenitor pair model is a _genetic_ sole-progenitor pair, not a _genealogical_ sole-progenitor pair as in [The Genealogical Adam and Eve](https://www.ivpress.com/the-genealogical-adam-and-eve) _:_ _The Surprising Science of Universal Ancestry_ by S. Joshua Swamidass. Obviously, a sole-(genetic)-progenitor pair establishes them as a sole-(genealogical)-progenitor pair as well. For the time being we lay aside any question or consideration of possible interbreeding of human ( _Homo sapiens_ ) populations with other hominins, especially in time ranges where human and Neanderthal and/or human and Denisovan populations over-lapped geographically.

Either you misremembered or AJ Roberts is consistently wrong about the RTB model.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 20, 2021, 2:45am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/18 "2021-07-20T02:45:40Z")

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OK, I see this quote from the article as contradicting your idea of what “sole progenitor” means to AJ Roberts:

> [@](#):
>
> Certainly, _if_ God intended an entire human population to arise from a _de novo_ pair, and _if_ no other source of human genetic diversity is allowed (because ours is a sole-progenitor pair model)

The linking of “no other source” and “because ours is a sole-progenitor pair model” seems to leave no room at all for anything other than a bottleneck of two and a meaning of “sole” in line with my expectations, not yours. Or did she misspeak?

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**Author:** ![swamidass](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/swamidass/32/3_2.png) [@swamidass](https://discourse.peacefulscience.org/u/swamidass)\
**Post date:** [July 20, 2021, 2:47am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/19 "2021-07-20T02:47:16Z")

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This in the context of developing a model that doesn’t allow neandertha-sapien interbreeding. Later on she relaxes that constraint. You can’t take that quote out of the larger context.

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**Author:** ![John\_Harshman](https://sea2.discourse-cdn.com/flex016/user_avatar/discourse.peacefulscience.org/john_harshman/32/1121_2.png) [@John\_Harshman](https://discourse.peacefulscience.org/u/John_Harshman)\
**Post date:** [July 20, 2021, 3:08am UTC](https://discourse.peacefulscience.org/t/is-rtbs-model-sole-progenitor/13989/20 "2021-07-20T03:08:01Z")

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Clearly the meaning of “sole progenitor” at the time of the quoted bits was the one I would assume, not the one you’re talking about. Perhaps it changed later, but I haven’t seen the evidence. Surely this must call into question at least the idea that the term is generally understood the way you prefer.

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