Adam, Eve and Population Genetics: A Reply to Dr. Richard Buggs (Part 1)

[AMWolfe (Andrew M. Wolfe)]

…and if I come across a good pithy article on this from a non-Chomskian linguist, I’ll be sure to share it. It’s not something I’m currently reading about, but if I stumble across something, I’ll send it your way!

Incidentally, while we’re on the topic, I find it curious that the premiere organization of Christian field linguists, SIL International, leans largely non-Chomskian (with some exceptions). One might expect an organization with an American Evangelical base to lean toward the theoretical framework that resonates with ID… yet it doesn’t. And, ironically, it takes a fair amount of flak for that by Chomskian linguists in the secular academy. Quite a bit of irony there!

[DennisVenema]

@glipsnort

I’m not familiar with this estimate. Reference?

I’d like to see it as well. I’ve not noticed that (though it is a big field, so not surprising that I haven’t).

[Christy (Christy Hemphill)]

@Swamidass

Notably, its authors include the great Noam Chomsky, essentially making the main point I’ve been making here.

Could you please clarify what point you are making that you believe this article supports? Do you think it supports the idea that language could plausibly have emerged discontinuously in a single mating pair?

@Swamidass

Christy:

And then you went on to say we can’t know anything for sure.

(I did not say that).

Okay, that was my summary of your response to Dennis when you said:

@Swamidass

We do not know how quickly these things progressed. Do we? You are putting forward rationale for why it might be gradual, but there is rationale for why it might not be gradual too, at least at points. As far as a I know, from evidence, we cannot discriminate which one is correct (…) There are mysteries about the details of our origins. Rather than insisting our personal instincts are correct, its better to just say “we do not know.”

and again when you said:

@Swamidass

I’ve already said that the evidence is not going to tell us one way or another.

There is a difference between saying we cannot disprove that two individuals invented language de novo because the origin of language is a mystery and saying we cannot discriminate between plausible models of how language emerged in human communities and implausible models.

Fine, we can’t disprove the idea that two people invented language de novo and consequently geographically isolated themselves because they felt so different/superior with their new abilities that they didn’t want their children associating with the rest of their social group anymore. In my humble opinion, it’s still laughably implausible, and it doesn’t make sense to assert it as a real possibility under consideration by anyone who theorizes about these things. If you never meant to make it sound like that was what you were arguing, then sorry for misunderstanding your argument.

I was not trying to somehow insult you by pointing out it sounded like a creationist argument to me. I was just trying to get you to clarify what you were actually claiming, because “the evidence is not going to tell us one way or another” sure sounded to me like a pretty lame defense of your contention that maybe there was a two person bottleneck because of geographic isolation caused by two people inventing language and not wanting their kids to interbreed with anyone around them. The challenge wasn’t meant to be hostile in any way, just an invitation to make your presentation of options better. It seems like you don’t really appreciate that kind of feedback though and are just going to double down on how it really does make lots of sense, so I’m happy to drop the subject. I’m on vacation and I’m not trying to pick fights with anyone.

@Swamidass

(yet we have been unable to socially transmit language or theory of mind to the great apes)

I don’t understand what significance this piece of information has in your mind. So what? The issue is when has human language ever been transmitted non-socially?

@Swamidass

(no, we are talking about linguistic origin, not linguistic evolution, which is intertwined with biological evolution)

To me that is like saying that what we know about how genes work in the here and now has no bearing on studying the origin of our species. Yes, what we know about how languages are acquired and evolve in the here and now have bearing on what we theorize about how language worked at it’s origin. For language to qualify as language it has to function in certain predictable ways that we understand based on our study of contemporary languages and historical linguistics.

@Swamidass

Perhaps consider backing off the heated rhetoric,

It’s not heated rhetoric. It’s a conversation with someone who doesn’t think you have a good argument on one minor point. That’s what we do on this forum, we discuss stuff and occasionally disagree. Please relax a little.

[Swamidass (Peaceful Science)]

@DennisVenema

I’m not familiar with this estimate. Reference?

I’d like to see it as well. I’ve not noticed that (though it is a big field, so not surprising that I haven’t).

There was an error i made there, I misremembered the figure. THe paper to which I was referring:

http://www.pnas.org/content/113/4/812

t suggests a trajectory of continuous, long-term Wyoming-Colorado hunter–gatherer population growth of 0.041% from 13,000–6,000 cal BP, doubling roughly every 1,700 y, within which there were short-term fluctuations during which growth rates were sometimes more than an order of magnitude larger (i.e., r > 0.4%), doubling in less than 200 y.

A couple points I would make:

1. Hunter gatherer growth rates can be about the same as agriculturalists. Counterintuitively, the main difference might be in carrying capacity, not growth rate.

2. Rate is going to be inversely related with distance from carrying capacity. Smaller populations can grow percentagewise much faster than larger populations.

3. Doubling every generation for a few generations (when very far below carrying capacity) does not seem implausible. So, going from 2 → 4 → 8 → 16 → 32 → 64 etc. over a 150 to 200 year period (4 children for each couple) does not seem implausible, even if the long term rate moves lower once there are, say, over 100 or 1000 individuals.

4. Though I do agree that is faster than what was observed in North American hunter gatherers. What I said earlier was in error.

So thanks for pressing me on that reference. It was important to get that straight, especially for some of the simulations we have been doing.

[Chris_Falter]

@AMWolfe

And Chomsky’s linguistic theorizing is considered very poor-quality science by a great many linguists (not just Dan Everett of recent Forum mention).

Chomsky famously has refused to acknowledge any value in probabilistic language models. Meanwhile, Google Translate and Bing Translate use them to great effect.

EDIT: iirc, Alexa is more accurate in listening to and transcribing language on the fly than the average adult. And probabilistic models are behind that capability, of course.

[AntoineSuarez]

@agauger

Animals have been represented as having rudimentary language, but when compared to what even two year old humans are capable of, it is clear there are significant gaps.

It seems to me you are searching for a feature capable of sharply distinguishing between human Image Bearers, and non-human animals.

But then why do you not refer to writing?

Notice that writing is motivated by the need of registering marriages, arranging contracts, and enacting laws. Therefore it reveals awareness of personal identity, moral responsibility and accountability.

[AMWolfe (Andrew M. Wolfe)]

@AntoineSuarez

But then why do you not refer to writing?

For what purpose are you suggesting referring to writing, may I ask?

Writing is a very recent phenomenon in the history of H. sapiens, and does not extend to many human contexts and languages even today. Are you suggesting (perish the thought) that these peoples are somehow less human??

I’m not sure I get where you’re going with this.

[Bill_II]

@AntoineSuarez

Notice that writing is motivated by the need of registering marriages, arranging contracts, and enacting laws.

Writing is motivated by the need to record the verbal agreements that resulted in marriage, contracts, and laws. Social behavior predates writing. Antoine what you should be looking for are indications of group behavior that would lead to language that would lead to cities that would lead to writing.

[Christy (Christy Hemphill)]

@AMWolfe

Incidentally, while we’re on the topic, I find it curious that the premiere organization of Christian field linguists, SIL International, leans largely non-Chomskian (with some exceptions).

True. I’ve never met anyone personally who uses transformational grammar to describe minority languages. One critique I commonly hear is that it tends to see all languages through an “English as normal,” indo-european-centric lens, which introduces all sorts of complications when you are doing descriptive linguistics of languages that function very differently than English. Everyone I know uses Role and Reference Grammar or Lexical-Functional Grammar.

[glipsnort (Steve Schaffner)]

@Swamidass

t suggests a trajectory of continuous, long-term Wyoming-Colorado hunter–gatherer population growth of 0.041% from 13,000–6,000 cal BP, doubling roughly every 1,700 y, within which there were short-term fluctuations during which growth rates were sometimes more than an order of magnitude larger (i.e., r > 0.4%), doubling in less than 200 y.

A couple points I would make:

Hunter gatherer growth rates can be about the same as agriculturalists. Counterintuitively, the main difference might be in carrying capacity, not growth rate.

Rate is going to be inversely related with distance from carrying capacity. Smaller populations can grow percentagewise much faster than larger populations.

Doubling every generation for a few generations (when very far below carrying capacity) does not seem implausible. So, going from 2 -> 4 -> 8 -> 16 -> 32 -> 64 etc. over a 150 to 200 year period (4 children for each couple) does not seem implausible, even if the long term rate moves lower once there are, say, over 100 or 1000 individuals.

Though I do agree that is faster than what was observed in North American hunter gatherers. What I said earlier was in error.

So thanks for pressing me on that reference. It was important to get that straight, especially for some of the simulations we have been doing.

To be clear, what you’re postulating is very much what I would call explosive growth. So back to my question: what kind of natural disaster are you postulating that would leave the environment intact enough for explosive growth to occur immediately afterwards?

@Swamidass

Also there is a genetic interference as a possibility too.

Again, what are you actually proposing? What kind of genetic interference creates a bottleneck of two in mammals? What examples are there?

@Swamidass

(just like is the case for all scientific theories, Duhem–Quine thesis - Wikipedia)

No. Just no. Sure, there are an infinite number of possible hypotheses that can explain any set of data. No, science does not treat all hypotheses equally – it has heuristics that let scientists drastically restrict the set of hypotheses that they actually consider.

Remember, my claim was that “abrupt bottleneck of size two” and “slowly varying population size” should not be treated as equally valid scientific hypotheses. You haven’t given me any reason to change my view.

[AntoineSuarez]

@AMWolfe

For what purpose are you suggesting referring to writing, may I ask?

In order to single out a criterion allowing us to sharply establishing when God makes Humanity to a community of people in the Image of God.

I have the impression is what Ann Gauger is looking for after all, isn’t she?

@AMWolfe

Writing is a very recent phenomenon in the history of H. sapiens

The beginnings of Homo sapiens as an evolving biological taxon is a matter of arbitrary definition and are therefore necessarily fuzzy.

So what matters here is not “the history of evolving Homo sapiens” but establishing the beginning of the history of Humanity as community of Image Bearers.

@AMWolfe

and does not extend to many human contexts and languages even today. Are you suggesting (perish the thought) that these peoples are somehow less human??

Not at all!

Consider those in this thread who propose language as the criterion for distinguishing humans from animals:

Are they suggesting that new-born babies or hydranencephalic childs “are somehow less human”?

No. Their argument amounts to establish the time T when language appears, and then infer: all creatures exhibiting a human body after time T cannot be considered animals.

Similarly I argue:

The time when writing appears at about 3500 BC marks the moment when God makes the first humans in His Image: It is the moment referred to in Genesis 1:27. After the Flood all the extant human-like animals are made to Image Bearers: It is the moment referred to in Genesis 9:6; in the wording of @Bill_II one could say: at this moment the percentage of Image Bearers among human-like animals becomes 100%. In the time between this percentage increased both, by children generation and by further direct creation by God of “sons of God”, according to Genesis 6:1-4.

Since the moment referred to in Genesis 9:6 the percentage of Image Bearers among humans is 100% forever, independently of they write or not.

This thread is showing that “language” is highly controversial as a cut-off criterion. So it may be worth to try with writing.

@AMWolfe

I’m not sure I get where you’re going with this.

I hope it is now clearer. If not, I will be pleased answering further comments.

[Christy (Christy Hemphill)]

@AntoineSuarez

But then why do you not refer to writing?

Notice that writing is motivated by the need of registering marriages, arranging contracts, and enacting laws. Therefore it reveals awareness of personal identity, moral responsibility and accountability.

Thousands of languages/cultures today do not have writing systems. Are they less image bearers, or less moral? Isn’t it problematic that writing was specific to relatively few societies until modern times?

[AMWolfe (Andrew M. Wolfe)]

@AntoineSuarez

After the Flood all the extant human-like animals are made to Image Bearers: It is the moment referred to in Genesis 9:6; in the wording of @Bill_II one could say: at this moment the percentage of Image Bearers among human-like animals becomes 100%.

To me this is an utterly bizarre interpretation of Genesis 9:6, but I am willing to be shown wrong. By chance are you aware of any scholarly commentaries that take this approach to that verse, namely that this moment of bestowing God’s image in this verse refers to a separate moment in time from humanity’s initial creation?

Forgive me if you’ve covered this in the other long thread with your name in the title. I have not been following that conversation at all.

[Swamidass (Peaceful Science)]

@glipsnort we are going far afield from the original goal into speculative territory.

The question, as I see it, is if a brief bottleneck is ruled out in the distant past by evidence.

As for the likelihood this, it will be strongly shaped by our prior beliefs, because there is not evidence to tell us one way or another.

Some people come to the table already believing that there was single couple origin. Some of us will dispute whether that is warranted (I certainly do), but that is their starting point based on their reading of Scripture. I do not think there is good reason to think there as a single couple origin from the scientific data alone. It seems like that is what you are asking for, but that data does not be possible to find.

“Explosive” growth is a highly biased term in this context. We are merely talking about the difference between 3 (observed in hunter gatherer societies) vs. 4 (what I initially said) children per couple, for just a couple centuries. This is hardly an absurd amount of growth, clearly in the realm of plausibility. We can look for the sensitivity of coalescence methods (PSMC and MSMC) to detecting tight bottlenecks with different growth rates afterwards. TMR4A is at about 500 kya, but I expect that number to move upward to about 600 to 700 kya with a growth rate you would find acceptable (e.g. 0.4% vs. 1%, or 3 children per couple instead of 4).

As for what could cause this?

That is irrelevant to the point. We are talking about what the data shows us. I can speculate totally untested natural mechanisms for a single couple origin, and have. However that is just speculative and not supported by data. I never claimed it was. There is not data here to discriminate.

People who think this is important for theological reasons, I am sure, are not making a scientific point. They would see that the data does not rule out a single couple origin during this time. Perhaps God made a couple and isolated them from their neighbors. We are not really talking science here. Once trust in that position will be entirely determined by theology (and not contradicted by evidence), but it is not my personal view, so do not ask me to justify it theologically.

I think large part of the confusion here is understanding how theological questions should negotiated the line between science and not-science.

From a purely scientific view, I think we can say:

1. There does not appear to be evidence against a brief single couple bottleneck before about 500 kya, but that might be pushed back to about 700 kya or so.

2. There does not appear to be evidence for such a bottleneck either.

3. We cannot find good reason to think from a purely scientific point of view why precisely a single couple bottleneck would be expected, but there may be some reasons a small bottleneck might have taken place (e.g. natural disaster, etc.)

However, now thinking from a theological point of view, engaged with this science, we can take this further, beyond the science.

1. Perhaps God created the first humans as a single couple, sole-genetic progenitors of us all, perhaps 2 mya.

Is that ad-hoc? Well, I’m not convinced by it, but I also cannot argue from evidence that it is wrong. If other’s feel it is not ad hoc, they can take that position. It really is not for science to say one way or another where the evidence is silent.

That is all I’m saying.

[Swamidass (Peaceful Science)]

@Swamidass

“Explosive” growth is a highly biased term in this context. We are merely talking about the difference between 3 (observed in hunter gatherer societies) vs. 4 (what I initially said) children per couple, for just a couple centuries. This is hardly an absurd amount of growth, clearly in the realm of plausibility. We can look for the sensitivity of coalescence methods (PSMC and MSMC) to detecting tight bottlenecks with different growth rates afterwards. TMR4A is at about 500 kya, but I expect that number to move upward to about 600 to 700 kya with a growth rate you would find acceptable (e.g. 0.4% vs. 1%, or 3 children per couple instead of 4).

I should add that the whole analysis is very tightly dependent most sharply on how many children Adam and Eve have. If they have, say, 8 kids, and then it goes down to just 0.4% growth from 2 centuries, then down to 0.04% long term, it would be very hard to detect.

Having 8 kids in one family is not at all implausible.

[gbrooks9 (George Brooks)]

@Swamidass

Having 8 kids in one family is not at all implausible.

And having 3 of them die is quite within reason in a world without doctors and lots of physical risks…

[AntoineSuarez]

@AMWolfe

To me this is an utterly bizarre interpretation of Genesis 9:6, but I am willing to be shown wrong. By chance are you aware of any scholarly commentaries that take this approach to that verse, namely that this moment of bestowing God’s image in this verse refers to a separate moment in time from humanity’s initial creation?

Forgive me if you’ve covered this in the other long thread with your name in the title. I have not been following that conversation at all.

The question was discussed in the thread “My Theory about the Flood”. For the sake of accessibility to interested readers I develop my argument with pleasure in the follow:

First of all let me remark that about 362,000 humans in God’s Image are created each day around the world presently, that is, in “a separate moment in time from humanity’s initial creation”. So to this extent my interpretation regarding Genesis 9:6 is nothing bizarre.

Presumably you are astonished because I claim that Genesis 9:6 refers to the creation of Image Bearers the same way as God created the first ones (“Adam and Eve”). i.e.: by endowing human-like animals with capability to freely love Him.

Notice however that Genesis 6:2-4 explicitly refers to human beings called “sons of God” the same way as Adam is called “son of God” (Luke 3:38): This means that the “sons of God” in Genesis 6:2-4 were created the same way as Adam was created but in a separate later moment.

Gordon Wenham [Word Biblical Commentary I, Genesis 1-15, Word books: Dallas, 1987] following Claus Westermann claims:

Genesis 9:3-7 explain “why human life is specially protected, but animal life is not”, and proclaim “the inviolability of human life” that follows from “the unique right of God over life and death”: “Every single violation of this limit, be it based on national, racial or ideological grounds is here condemned” [p. 251]. Indeed the remark in Genesis 9:3 concerning food indicates a degree of distinction between humanity and the animal kingdom that was lacking in the vegetarian diet of Genesis 1:29 [p. 263-264]; and in Genesis 9:5-7 appears for the first time the prohibition of killing any creature belonging to humanity because mankind is made in the image of God.

One may wonder why this distinction and this prohibition were omitted in Genesis 1:26-29, as the “image of God” is mentioned for the first time. And even more astonishing is that the prohibition was omitted in Genesis 4:15, where to protect Cain God does not proclaim that he shares human blood and belongs to mankind but “put a mark on Cain so that no one who found him would kill him.” A reasonable explanation for such an “omission” in divinely inspired Scripture is that a sharp distinction between human and animal life would not fit with the ontological status of pre-diluvian Creation; such a distinction is appropriate only once all human-like animals on the earth were transformed into human persons. Since this allegedly happened after the Flood, only then (Genesis 9:5-7) God categorically proclaims that the right to life, foundation of the personal rights, is defined by the belonging to humanity. And here we meet to some extent the interpretation of Hendel, R. S.: The Flood narrative with its introductory pericope of the “sons of God” ends ordering “the human cosmos” [Of Demigods and the Deluge: Toward an Interpretation of Genesis 6:1-4, Journal of Biblical Literature, Vol. 106, No. 1 (1987), pp. 13-26, and References therein]. The ordering happens mainly by means of an explicit formulation of the foundation of rights and law.

Please let me know whether I have answered your question or you desire further clarifications.

[AMWolfe (Andrew M. Wolfe)]

@AntoineSuarez

Please let me know whether I have answered your question or you desire further clarifications.

I won’t derail this very important Buggs-Venema-Swamidass-Schaffner thread further with these matters, particularly if this has already been discussed elsewhere on the Forum (at length, apparently, during the months when I took a break from the Forum).

My opinion on your theory does not matter in the least, but I do find it quite implausible. I will leave it there. If you wish to continue, you can start a new topic.

[AntoineSuarez]

@AMWolfe

My opinion on your theory does not matter in the least, but I do find it quite implausible. I will leave it there. If you wish to continue, you can start a new topic.

I would appreciate knowing why you find it implausible. Since the issue is related to transmission of original sin I would like to suggest you post the reasons in this other thread.

Nonetheless I think it would be also fitting posting here since in the end the question at the core of the debate seems to be:

Is it theologically necessary that all Image Bearers are genetically or at least genealogically descended from a single couple?

I would be thankful to know your answer to this question.