Ann Gauger's latest salvo against Dennis Venema's arguments against an original pair of human beings

This will be my last response, as I have other work to do. I am not stating my own position in this article. I am reporting what Buggs said and his statement is that he accepts common ancestry at least as far as his argument goes. As for my opinion I have answered that elsewhere. Let me ask you this. How would you distinguish between a large population with a sudden bottleneck of two from a starting population of two with equivalent heterozygosity? Would there be a way to tell the difference between them?

No, I don’t. Most of the argument in Adam and the Genome is based on LD, ILS, etc.
The main reason why Buggs is off base is because he equates heterozygosity with genetic diversity, when it is a very poor/crude measure of same.

Steve, I’ll send you the book if you’d like. PM me your mailing address if you want a copy.

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Yes. Patterns of linkage disequilibrium. Easy to tell the difference.

Edit: I think I misunderstood what you were asking here.

If I understand you correctly, you’re correct. A population of two and a bottleneck down to two would be equivalent.

Oh, I’ve got the book – got it in Houston. I just haven’t read it yet. That’s a characteristic it has in common with lots of books in my house.

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Your argument works as well against Venema as it does against Buggs.

But you said “Does Science Rule Out a First Human Pair? Geneticist Richard Buggs Says No”, when that is not what Buggs actually said.

Palaeontological evidence for a previously large population, rather than for a starting population of only two. In the specific case under discussion, we have abundant palaeontological evidence for a previously large population.

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That depends on where you place the starting population, doesn’t it?

Thanks all for an interesting discussion.

450,000 years from a single couple? What was the effective population that von Salome used for this conclusion? Also:

"Among them is the class II locus HLA-DRB1, with more than 400 known alleles."

That’s only 400 alleles, and it took 450,000 years with I would presume a largish population. With HLA-A we are talking about over 4,000 alleles.

The problem is that Buggs’ response does not contain any scientific justification for doubting the overwhelming evidence for a lack of a bottleneck. It is just his opinions and emotional responses. We don’t see any scientific evidence to make us doubt things like the SNP/LD data.

Also, estimates of current effective population size for the human population seriously underestimates the consensus population . . . by several billion.

"Phase I of the HapMap project produced between 18 and 22 million SNP pairs in samples from four populations: Yoruba from Ibadan (YRI), Nigeria; Japanese from Tokyo (JPT); Han Chinese from Beijing (HCB); and residents from Utah with ancestry from northern and western Europe (CEU). For CEU, JPT, and HCB, the estimate of effective population size, adjusted for SNP ascertainment bias, was ∼3100, whereas the estimate for the YRI was ∼7500, consistent with the out-of-Africa theory of ancestral human population expansion and concurrent bottlenecks."
http://genome.cshlp.org/content/17/4/520.abstract

Obviously, there are more than 10,000 people on the Earth. It is a big mistake to view the effective population size as the consensus population size.

Thanks for the tip. HLA-A may provide some interesting data for us.

I haven’t read Venema’s book either, but I suspect that this ASA paper is probably a distillation of what is in the book. It mentions levels of ILS, coalescence models from a comparison of the chimp/gorilla/human triad, and the SNP/LD data.

Yep - they are similar - although the book uses up-to-date stuff (that article is now seven years old).

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The issue is that he very obviously places the starting population in a completely different place to what your title implies. That is a gross misrepresentation of his argument.

Jon, I don’t know what you’re talking about. Who is “he”? What time frame was implied where? As far as I know Richard Buggs article said nothing about any timeframe. If you mean Dennis Venema then he accepts the standard date I would assume. 2 million years to Homo erectus, 200,000 years to the first modern human (make that 300,000 years now), 80,000 years to migration out of Africa, 40,000 years until the first cave art… Where would you like to place the first human being? I go back to the beginning with Homo erectus. Who did I so grossly misrepresent?

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Hi Dr Gauger,

Thanks for coming to the forum and participating in a robust discussion with plentiful citations to evidence.

What you seem to be hypothesizing is that the first human couple might have lived perhaps as recently as 200 - 300 kya, and that H Sapiens Sapiens, now 7 billion strong, descended from that one couple. Am I understanding you correctly?

If so, the Biblical evidence would strongly refute that that couple is the Adam and Eve of Genesis. Adam and Eve lived an agricultural life, for example–and archaeology tells us that the first agricultural societies emerged about 10 kya. Just a few generations later their descendants were building or living in cities that are recognized in the archeological record as having been founded less than 10 kya.

In other words, while your pop gen modeling may produce interesting new insights about ancestral populations (perhaps even a single couple) that lived on the order of 105 years ago, it would not seem to have any bearing on the question of the historicity of Adam and Eve.

Does that make sense?

Grace and peace,
Chris Falter

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[content removed by moderator] I am referring to Buggs.

As you know very well, Buggs accepts common descent, and the bottleneck pair he is talking about is a pair of people who were preceded by a prior population. He is very obviously not talking about a “first human pair” who were specially created by God and did not descend from a previous population.

At least to the first modern human. But my views are beside the point.

You cite Buggs in order to oppose Venema’s argument that the genetic evidence rules out the idea that the entire human population descended from Adam and Eve as the first human pair. But the human pair to which Buggs refers is not the first human pair in the way Adam and Eve have traditionally been understood theologically, and the criticism of Venema which Buggs makes does not support the idea that the entire human population descended from an Adam and Eve who were created de novo rather than being descended from a previous population.

What you could have said was “Buggs’ comments support the idea that Adam and Eve were not created by God but were in fact the descendants of pre-human ancestors”. [content removed by moderator]

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That is the same question I asked previously, and the same point I made previously. Unsurprisingly, it went unanswered.

Precisely.

You cite Buggs in order to oppose Venema’s argument that the genetic evidence rules out the idea that the entire human population descended from Adam and Eve as the first human pair. But the human pair to which Buggs refers is not the first human pair in the way Adam and Eve have traditionally been understood theologically, and the criticism of Venema which Buggs makes does not support the idea that the entire human population descended from an Adam and Eve who were created de novo rather than being descended from a previous population.

It would appear that you are reading more into my language than is there. My title, which I think is what you are angry about, is Does Science Rule Out a First Human Pair? Buggs explicitly argues that a single breeding pair can retain most of its heterozygosity as long as the population it founded expands rapidly. In other words a first pair is possible.

By ‘first human pair’ I meant the first pair to be fully human, coming from a bottleneck of two, which is what Buggs said could not be ruled out. A bottleneck of two can happen at least three ways I can think of: by a sudden reduction in population size from a pre-existing population because of isolation or who knows how, by de novo creation, or by the sudden imparting of a different character to two individuals. Buggs suggests the first is a possibility. I did not contradict him or misrepresent him, despite what you may think. I think you have read into my words what was not there.

However it happened, that party of two would be the first human pair. When did it happen? The answer depends on what weight you give to various pieces of evidence. Chris Falter favors a recent date because of scripture and archeological evidence, apparently. I favor an earlier date, earlier even than you perhaps, Jon, at the time of the appearance of Homo erectus, because of anatomy and genetics (common ancestry with Neanderthals and Denisovans). Where did it happen? Africa as far as I know. There are arguments against this time frame, I know. But it gives plenty of time for the minor allele frequencies to recover, if there was a bottleneck of two.

It’s late. I am tired of trying to defend myself. You, for your part, should take me at my word. If you can’t accord that respect to me, I suggest rereading the posting guidelines.

Adam and Steve? Chris, you know good and well this forum is not the place to talk about politically charged issues. :wink:

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