Friday, October 23, 2009

229. The Baseline Scenarios -- part 5

The genetic evidence discussed in my previous post strongly suggests that the Hypothetical Baseline Population (HBP) was indeed a single group, possibly a small band, living somewhere in Africa, prior to the time of earliest divergence from HBP of either proto-Pygmies (PP) or proto-Bushmen (PB), with estimates ranging from Tishkoff's extremely conservative >35,000 years ago, to Chen's 77,600 - 102,000 spread. The same evidence also points to certain Pygmy and Bushmen groups of today as their most direct descendants, in that they carry the deepest mtDNA, Y chromosome and nuclear microsatellite clades. This is not fanciful conjecture, but very respectable science, supported by a growing consensus of specialists in both biology and anthropology.

We are now in a position to propose some very specific answers to the Overwhelming Question first raised in posts 182-194 (see Table of Contents, above): where do we come from? i.e, who were our ancestors and what were they like? or more precisely: what was HBP like? Prior to the advent of modern population genetics such a question would have seemed absurdly out of reach. But, amazingly enough, we now have more than sufficient evidence to formulate some very reasonable hypotheses.

Our method will be simple. Any attribute found to be shared by at least one group in each of the three populations with the deepest clades, i.e., Eastern Pygmies, Western Pygmies and Bushmen (EP, WP, Bu), should be taken seriously as a possible survival from the time the ancestors of all three groups were united as one -- the group I'm calling HBP. You could call this the "triangulation method."

Thus, for example, the short stature to be found in all three populations suggests that most or all HBP could also have been short. According to the Encyclopedia Britanicca, anthropologists define pygmies as any group whose adult males grow to less than 150 cm (4 feet 11 inches) in average height. Mbuti, according to the same source, average under 4 feet 6 inches in height. Some BaAka adults have been reported at exactly 4 feet in height. According to the 1911 edition of the Britanicca,
[t]he most striking feature of the Bushman's physique is shortness of stature. Gustav Fritsch in 1863-1866 found the average height of six grown men to be 4 ft. 9 in. Earlier, but less trustworthy, measurements make them still shorter. Among 150 measured by Sir John Barrow during the first British occupation of Cape Colony the tallest man was 4 ft. 9 in., the tallest woman 4 ft. 4 in.
While it's also been reported that other Bushmen populations average to more or less "normal" height, the remarkable shortness of at least some such groups cannot be ignored. If WP, EP and certain Bu groups can thus be considered "pygmies" as far as height is concerned, then it does seem likely that their common ancestors, HBP, were also of "pygmy" height. This makes considerable sense when we realize first, that there is no real evidence that pygmy stature is necessarily an adaptation to rainforest conditions (though it could be); second, that HBP could have originated in the Central African rainforest in any case; third, that tallness seems a more likely adaptation, in strictly Darwinian terms, than shortness, since a larger person has certain very clear advantages over one who is smaller. (We must also remember that HBP is not necessarily representative of either the earliest "modern" humans or all their contemporaries. Thus, fossil evidence of early humans of normal or greater height would have no bearing on the height of HBP, who would have been, in all likelihood, only one of a great many modern humans living in Africa at the time.)

Biological research, as reported in Patterns of Human Growth, 1999, by Barry Bogin, suggests that pgymy size may be due to unusual endrocrine levels, produced by a "genetic defect in the cellular mechanisms for the production, release or cellular reception of IGF -1" (p. 375). Since levels of IGF-1 have been found to be significantly lower in pygmies, this hypothesis seems likely.

A recent study of Andamanese pygmies, by Jay Stock and Andrea Migliano, offering a very different and imo highly unlikely, explanation, based on recent historical factors (ala classic revisionist dogma) has been criticized for several reasons, the most decisive offered by Anthropologist Brian Shea of Northwestern University, who
calls such evidence “interesting but irrelevant to the origin of small body size in human pygmy groups.” Stock and Migliano document short-term, environmentally induced changes in height that would affect the size of any population, Shea contends. This process can’t explain the origin of pygmies, he says.
I'm not sure whether the IGF-1 levels of Bushmen have been studied, but if they are also low, that would seem to settle the matter in favor of short stature as a trait inherited from a common ancestor by all three groups. Since HBP is the common ancestor, this means HBP would most likely have been of pygmy height as well. On the other hand, if Bushmen IGF-1 levels are found to be normal, then either the IGF-1 hypothesis is wrong, or Bushmen height is not inherited from HBP. If that were the case, then we would have no way of knowing whether HBP were short, tall or of medium height.

Turning to other phenotypical characteristics, steatopygia, an unusual degree of fat accumulation on the buttocks, has been noted in both Pygmies and Bushmen, making it likely that this condition was almost certainly inherited from HBP. In almost all other respects, however, Bushmen are morphologically very different from Pygmies, or indeed any other contemporary people. If HBP resembled today's Pygmies, then Bushmen morphology would represent a mutation or set of mutations from the HBP norm. On the other hand, if they resembled Bushmen, then the Pygmies would be the carriers of such mutations. It's possible they resembled neither, and as of now we seem to have no way of telling.*

A similar situation exists for language.

That the genetic evidence has significant meaning for the study of cultural history has been noted by several geneticists, though the possibilities have not yet been widely explored. Since the pioneering work of Cavalli-Sforza, there has been an effort to correlate the genetic findings with those of historical linguistics, but the results have not always been consistent, for obvious reasons, since languages can easily change in a very short time, due to historical factors. We know this to be the case in Africa, since the spread of Bantu languages is almost certainly due to the relatively recent (ca 3,000 ya) Bantu expansion.

Sarah Tishkoff et al. alluded to the linguistic evidence as follows, in their recent Science article on Africans and African Americans:
The shared ancestry, identified here, of Khoesan-speaking populations with the Pygmies of central Africa suggests the possibility that Pygmies, who lost their indigenous language, may have originally spoken a Khoesan-related language, consistent with shared music styles between the SAK (Southern African Khoesan) and Pygmies (p. 1041).
Since, as Tishkoff notes, all Pygmy groups lost their original languages (assuming they had any to begin with) and now speak languages related for the most part to those of their agriculturalist neighbors, we have no way of knowing what sort of language was spoken by HBP, or indeed if they had any language at all. As Tishkoff implies, the same is not true of music, since there are "shared music styles between the SAK (Southern African Khoesan) and Pygmies" (a specific reference to Lomax's work). If the lack of a shared verbal language can be seen as a serious drawback to any attempt to connect EP, WP and Bu culturally, the presence of shared musical styles easily makes up for it. Because music too is a language, though much neglected by anthropologists, for reasons already discussed at some length in earlier posts.

Much of my blog has been devoted to this very point, but in my next post I'll review the all important musical evidence, for the benefit of latecomers.

* [added at 2:32 PM, same day] I just had a bit of a brainstorm on the question of whether HBP would have been closest in morphology to Bushmen or Pygmies. If we take another look at the phylogenetic trees in the previous post, it's apparent, in all three cases, that the Bushmen occupy the deepest clades. Moreover, all these clades are dead ends. If the deepest clades are occupied by haplogroups found largely today among Bushmen, that strongly suggests that the ancestral group (HBP) could have resembled Bushmen. If that were the case, then the oldest ancestors of the Pygmies would have been the first group to diverge from the ancestral group, which is consistent with Chen's finding that the Biaka Pygmies were the first to diverge.

We would then have the following historic sequence: 1. A proto-HBP group either resembling today's Bushmen morphologically, or evolving in that direction, until we reach 2. HBP, resembling Bushmen; 3. the development and divergence of the first Pygmy or Proto-Pygmy (PP) population from HBP, due possibly to a population bottleneck or some other type of founder effect (due to banishment, accidental isolation, etc.); 4. the gradual expansion and migration of the original HBP population until it populates most or all of southern Africa with Bushmen-like people -- since all or most of the Bushmen clades are dead ends, the evidence suggests that HBP did not give rise to any other non-Bushmen populations, but remained relatively static (we are admittedly hampered here by a lack of Hottentot DNA, a serious gap since the Hottentots are generally thought to have been a Bushmen derivation); 5. the migration of the proto-Pygmy group (PP) into the Central African Forest, where it expands to eventually produce all the Pygmy groups we know today; 6. the development and divergence of a Proto-Bantu population from a Pygmy group, roughly 18,000 years ago, according to the genetic evidence.

If we assume, on the other hand, that HBP were more Pygmy-like, this would, first of all be inconsistent with current genetic evidence placing Bushmen at the deepest clades. If that were nevertheless the case, then we might have the following sequence, which would in fact be fully consistent with Chen's table: 1. A proto-Pygmy group, ancestral to the WP (Biaka), is the first to diverge, ca 70,000 to 100,000 years ago; 2. a proto-Bushmen group, ancestral to the !Kung, develops from HBP, due to some sort of founder effect or population bottleneck and diverges from the ancestral group between 41,000 and 54,000 years ago; 3. yet another Pygmy group, ancestral to the EP (Mbuti), diverges from HBP roughly between 14,000 and 19,000 years ago. If the ancestries of EP and WP are so completely separate from one another, by such a long time span, it's very hard to understand how both groups would have made their way separately into the Tropical Forest. Which tells us either that this second scenario is highly unlikely, or that HBP developed originally within the Tropical Forest, from which PB ultimately migrated.

17 comments:

Maju said...

How would you explain your claim that the HBP would be just a "small band"? I just can't make much sense of that. Would it be a small population (made up of many bands), then it would make better sense, IMO, as small bands are always subunits of larger groups in forager societies.

DocG said...

It's important to distinguish between the group of which HBP could have been a part, and HBP itself, which might well have been a small subset of that group, i.e., a band. I guess my thinking is that the root of our ancestral tree need not have consisted of all that many individuals.

It's more likely, however, that the first group to diverge from HBP could have been very small, but that HBP itself could well have been a sizeable population, with similar morphology, genetics, traditions, etc. So, yes, you have a good point.

By the way, I said it was only "possibly a small band." But it would be interesting to speculate on its size and also the size of the first group to diverge.

Maju said...

I tend to think of them instead as one or rather several populations with some size. There are two possible ancestral regions: Eastern or Southern Africa. In the latter case, the ancestral group of most humans would have diverged from proto-Khoisans, in the other case, it'd be the inverse.

By c.100,000 BP we find nearly identical decorative remains (beads) in North and South Africa, as well as in Palestine. This is the kind of evidence that suggests me that a widespread (even if small) single population or interconnected set of populations were foraging in all the savanna/steppe areas of Africa. However the haploid DNA (very specially Y-DNA) may have originated in some more specific group/s.

What the Khoisan/others "imperfect" genetic divide tells us is rather of the latest moment of intense interaction (large gene flow) between these groups, which is necessarily older than the HBP in its restrictive sense.

I have a feeling that this is like trying to find out about the Big Bang and getting stuck at the instant just after it, as happens in astronomy today. Like the BB, the HBP might be not resoluble, not at the detail you seem to wish for.

But we can , I believe, detect the moment when the southern population (proto-Khoisans) and the northern one (proto-others) finally split up. And then also when proto-Pygmies diverged, probably as result of their migration to the woodlands (in this case, I'm pretty sure that the mother group is that of the "others").

It's more likely, however, that the first group to diverge from HBP could have been very small.

For me it is more a moment when the two groups begin living as different ones. However it is very reasonable to think of proto-Khoisans as parent group and the others as derived (hence the smaller founder population). But the opposite can also be argued for, I guess. And you could even think of smaller migration episodes after the divide was first created (no absolute barriers in Africa).

In any case, what is shared by Khoisan (1st global divide) and Pygmy (1st divide in the northern group) is likely to be indicative of ancestral for all humankind. In this I agree with you (regardless of the issue of size, that I still have a hard time swallowing).

DocG said...

"There are two possible ancestral regions: Eastern or Southern Africa."

Why not the Tropical Forest region as a third possibility?

"By c.100,000 BP we find nearly identical decorative remains (beads) in North and South Africa, as well as in Palestine. This is the kind of evidence that suggests me that a widespread (even if small) single population or interconnected set of populations were foraging in all the savanna/steppe areas of Africa."

There is evidence that very similar beads used by Bushmen today could be survivals from the same culture that produced the prehistoric ones, so that for me is a meaningful clue, yes. And if this evidence is widespread, as you say, that does suggest that HBC could have been widespread as well 100,000 ya.

"What the Khoisan/others "imperfect" genetic divide tells us is rather of the latest moment of intense interaction (large gene flow) between these groups, which is necessarily older than the HBP in its restrictive sense."

I'm not sure what you mean, but it sounds interesting. Can you expand on this idea?

I like the Big Bang analogy, which fits very well with what I'm attempting (and also with what the geneticists are doing, of course). I also like the way astronomers, cosmologists and particle physicists have worked together to investigate that mystery, an investigation that has led to many important results.

I'm not determined to resolve any of these problems in great detail, that's not really the point. What I want to do is investigate them and see how much detail we can find.

As for the rest, this is what I was hoping for, to get others like yourself interested in some of these possibilities, and thinking about the various alternative scenarios. I'm hoping some sort of collaboration could come out of all this.

German said...

Victor, if you believe the ancestors of modern humans were short, like Pygmies and some Khoisans, what triggered the loss of this trait in almost all populations outside of Africa? And by a "trigger" I don't mean such a vague notion as "bottleneck" or such a circular argument as a "migration out of Africa." Is short stature in Aeta, Andaman islanders and some Guatemalan peasants a result of retention of the ancestral African trait or parallel development?

Stock and others are actually trying to devise a theory to explain observable facts that is precise, predictive and doesn't involve a circular argument. If Shea wants to add lack of proteins or other nutritional ingredients into the explanatory mix, it's fine but it won't have any bearing on the antiquity of the Pygmies, the only thing that appears to matter to you, and it won't eliminate other factors.

Your desire to move away from evolutionism into a new era of comparative ethnology sometimes is so strong that it makes you essentially repeat evolutionary explanations sub rosa by making a combination of short stature, musical style and clicks into a universal stage in the evolution of modern humans remarkably retained in a narrow set of populations in Sub-Africa. Sub-Saharan Africa stops being an actual geographic area subject to the same historical processes as elsewhere on the globe and becomes a pseudonym for this evolutionary stage. The rest of human diversity becomes an epiphenomenon whose only historical meaning is the loss of these African traits.

Maju said...

Why not the Tropical Forest region as a third possibility? -

Nothing is impossible but the fossil record (and I'd dare say that even genetic genealogy) do not suggest that.

There is evidence that very similar beads used by Bushmen today could be survivals from the same culture that produced the prehistoric ones, so that for me is a meaningful clue, yes. And if this evidence is widespread, as you say, that does suggest that HBC could have been widespread as well 100,000 ya.

It might well be a moment of expansion, maybe related to the Pygmy branch and even (very arguably) to the Eurasian one.

In any case, I'd like to point that the most precise dates are like: 90,000 BP for North African (Aterian culture) and 75,000 BP for South Africa. The remains of Palestine were long ago dated to c. 130,000 BP but this old stratigraphic chronology is not really too trustworthy.

I can imagine two scenarios: (1) this is the period of migration to Southern Africa or, maybe more likely, (2) this is a period of some secondary migration to Southern Africa and the southern/northern split is actually older, at least in some part.

"What the Khoisan/others "imperfect" genetic divide tells us is rather of the latest moment of intense interaction (large gene flow) between these groups, which is necessarily older than the HBP in its restrictive sense."

I'm not sure what you mean, but it sounds interesting. Can you expand on this idea?
-

For instance, let's assume that there was a first split between the mtDNA L0 group and the L1-6 one, as phylogeny may suggest. If so the L1 lineages among Khoisan could belong to a second flow from the L1-6 people. Just an example, guess you can imagine even much more complex interactions and even flow between populations that completely replaces the Y-DNA lineages in one of them (via drift).

The latter case is often implicit in the usual age estimates that give much more recent dates for Y-DNA Adam than for mtDNA Eve.

However the Y-DNA Adam age (if could be estimated with accuracy, something I generally dispute) would still be meaningful of the last (pre-Neolithic) important gene exchange (migration?) between the two major early human populations.

I'm not determined to resolve any of these problems in great detail, that's not really the point. What I want to do is investigate them and see how much detail we can find.

I'm for that as well.

DocG said...

German: "if you believe the ancestors of modern humans were short, like Pygmies and some Khoisans, what triggered the loss of this trait in almost all populations outside of Africa? And by a "trigger" I don't mean such a vague notion as "bottleneck" or such a circular argument as a "migration out of Africa." Is short stature in Aeta, Andaman islanders and some Guatemalan peasants a result of retention of the ancestral African trait or parallel development?"

This is an excellent question. First of all, however, I have to insist that I do NOT believe the ancestors of modern humans were necessarily short. This is only a possibility I'm considering. Though I do see evidence that supports such a view, I think that more comparative biological research is needed before the question can be answered with any degree of confidence. If the Bushmen share the same hormonal profile that appears to inhibit Pygmy growth then it seems extremely likely that the shortness of both groups derives from their common ancestry, which means that HBP must also have been short. If not, then that connection cannot be made and we are again left in the dark as to the stature of HBP.

As for the other aspect of your question, which poses a very interesting problem, if all Africans were short like pygmies and bushmen, then we could easily assume that the OOA migrants were also short and the short stature of the groups you mention would very likely be a retention from Africa. But all Africans are not short and in fact some are very tall, so this leaves us with no easy answer. If you see an easier way of addressing this problem from your point of view (Out of America) please share.

I will at some point be focusing on the very important question of the physical nature and cultural makeup of the OOA group, but this question will be much easier to answer once we have a better understanding of HBP and HBC. Once we are in a position to speculate meaningfully on the stature of this key group, we'll be in a better position to speculate as to why the people you mention are so short.

DocG said...

German: "Stock and others are actually trying to devise a theory to explain observable facts that is precise, predictive and doesn't involve a circular argument."

As far as Stock's Andamanese study is concerned, I'm sorry but it offends my intelligence when I see an argument claiming that pygmies originated as the result of relatively recent contact with Europeans. On the face of it, that simply doesn't wash, it's absurd. The existence of Pygmies has been documented since ancient times in any case. As far as I can tell, they are basing their conclusions primarily on correlations alone, a clear example of Galton's problem. A correlation per se cannot establish cause and effect. A balanced review of this paper can be found here: http://www.wired.com/wiredscience/2009/10/why-pygmies-are-small/

As for the rest, you are making assumptions about my position that are simply untrue. I am most certainly NOT "making a combination of short stature, musical style and clicks into a universal stage in the evolution of modern humans." For one thing, short stature is not an essential part of my investigation of HBP and HBC, which is equally valid whether or not they were short. For another, clicks are neither here nor there, because they aren't found among any Pygmy group. And if there is a "universal stage," it is not determined by my arguments regarding music or anything else, but by the genetic evidence, which as far as I can see is decisive. What I'm doing now is extrapolating on the basis of genetic research that already implies the existence of HBP, in order to explore the various implications, both physical and cultural. I am not really positing anything but exploring certain possibilities.

I know you are very skeptical regarding OOAf generally, as you're convinced that modern humans originated in the Americas. Fine, you are entitled to your own view. But I'm wondering if the evidence supporting your view would enable you to do the sort of thing I've done, i.e., whether you are in a positon to propose a HBP and HBC of your own, based on your OOAm theory. If so, I'd love to see it.

DocG said...

Maju: "In any case, I'd like to point that the most precise dates are like: 90,000 BP for North African (Aterian culture) and 75,000 BP for South Africa. The remains of Palestine were long ago dated to c. 130,000 BP but this old stratigraphic chronology is not really too trustworthy."

The archaeological evidence is undoubtedly important, but it's important to remember that there may be no way to associate HBP with any archaeological site or the people who lived there. This is a rather subtle point that's easy to overlook, but the archaelogical evidence may well point to populations whose lineages did not survive to recent times, and if that's the case then how do we establish a clear link between them and HBP, since HBP is defined solely in terms of populations that HAVE survived to recent times? Which is not to say that the archaeological evidence doesn't produce extremely valuable clues -- but these clues need to be assessed with great care if we want to use them as tools for understanding HBP or HBC. Just because some bones and stones from the African Old Stone Age have been found, if they are the bones and stones of some line that eventually died out then it's possible that their culture might have been totally different from HBP or any of its descendants.

DocG said...

Maju: "What the Khoisan/others "imperfect" genetic divide tells us is rather of the latest moment of intense interaction (large gene flow) between these groups, which is necessarily older than the HBP in its restrictive sense."

I've thought more about this and I think I understand what you mean. Are you saying that the presence of the earliest haplotypes among non-Bushmen and non-Pygmy groups means that the ancestors of these other groups could be older than HBP? If so, then that's a very interesting possibility, sure. What would be needed would be a careful ethnographic study of these groups to see if there are any cultural survivals from this period that could represent a deeper historical level than HBP. I'm not prepared to deal with this sort of question at the moment, but it is certainly worth considering, yes.

Or am I still not understanding you?

German said...

"As far as Stock's Andamanese study is concerned, I'm sorry but it offends my intelligence when I see an argument claiming that pygmies originated as the result of relatively recent contact with Europeans."

The way I understood this study (as well as the previous one) is that historical demography (a combination of mortality rates and the onset of reproduction) determines phenotype. Stock didn't suggest that pygmies became pygmies in the past 200 years but he and others do question the necessary antiquity and mutual relatedness of pygmy groups around the globe. So your intelligence is safe, Victor. Convergence in biology is a powerful force and the hormonal kinship between Khoisans and Pygmies is rather a matter of similar demographic scenarios in the past 5000 years. I still need to see data on Khoisan stature, which apparently differs from one group to another.

"And if there is a "universal stage," it is not determined by my arguments regarding music or anything else, but by the genetic evidence, which as far as I can see is decisive."

The problem of evolutionism was in the idealization of certain groups of populations, whether Europeans who were "advanced" or foragers who were "primitive." In evolutionism, foragers were living fossils. You repeat the same mistake by idealizing African foragers as retaining a musical style for millions of years. There was no change, no simplification, no complexification, just pure survival. Then suddenly, once humans left Africa, they started losing it. Why?

It's easy to speculate on "baseline cultures" if you believe that you only need to study two human groups in Africa out of thousands around the globe to get at the root of human culture. Plus no one can really relate to your ideas as there's never enough data on test it. It'd be more interesting to me if you could develop more precise scenarios of what happened (say, with music) AFTER humans allegedly left Africa. But this is not something that you are interested in. Once again, your exaggerated focus on the remote and obscure past is very much a survival of evolutionism's interest in fossils of various sorts. Ironically, genetic evidence that you tout so much without much sophistication is "decisive" on more recent population processes, not on any baseline states.

The advantage of OOAm is that allows for a better resolution of population histories from 45,000 down to the present and for a better integration between, say, genetics and linguistics. In "The Genius of Kinship", I did suggest a few ideas on what you call "baseline culture" but this is far less important to me at this point than to develop a model in which genetics, demography, kinship systems and cultural evolution work in consonance.

DocG said...

"The way I understood this study (as well as the previous one) is that historical demography (a combination of mortality rates and the onset of reproduction) determines phenotype."

Yes, that's the assumption. But their test of that assumption isn't sufficient because a simple correlation in itself cannot determine a cause and effect relationship. This was Lomax's error also, as Erickson noted: Galton's problem.

Similarly if we find that both Pygmies and Bushmen share a certain hormonal condition that too is simply a correlation and can't in itself establish cause and effect. However, if we determine that this condition is found ONLY among unusually short populations and not among populations of normal height, then that takes us beyond the simple correlation and strongly suggests that the hormonal condition is responsible for the shortness of pygmy type humans. And unless some outside cause, such as diet or early chidbirth, etc., can be linked to the hormonal condition, then the simplest explanation, ala Occam's Razor, would be common ancestry.

As for the rest, once again you are treating my ideas as though they were assumptions, but they are not. If you can find a specific sentence anywhere in what I've written on this blog that contains a hidden assumption by all means call me out on it. But continually harping over very general aspects of my research that strike you as based on false assumptions is getting tiresome.

German said...

"If you can find a specific sentence anywhere in what I've written on this blog that contains a hidden assumption by all means call me out on it. But continually harping over very general aspects of my research that strike you as based on false assumptions is getting tiresome."

I don't mean to be facetious or keep flogging a dead horse but you just wrote elsewhere: "The ONLY assumption I make is the assumption that the population geneticists, such as Cavalli-Sforza, are on the right track. Even mathematics has to be based on certain givens that are assumed, such as axioms. All science is based on certain basic assumptions of this kind."

This is a huge assumption because it entails both the antiquity of Africans and the recency of Amerindians. You pretty much borrow answers to all the key issues of recent human evolutionary history from a different discipline. You don't need another one to build a house of cards. But you feel that you're somehow entitled to it because all science is based on certain axioms. You want your research to be scientific, but you emulate not the strengths of a scientific method but its weaknesses.

Compare two of the axioms/assumptions for the Out of America theory 1) modern humans have a single origin; 2) the original population was small and had limited genetic diversity. The first one is the essence of the 20 years of mtDNA, Y chromosome, microsat etc. research. The second one again is a consensus gleaned from the different genetic systems. I share these assumptions with you and other out-of-Africanists. But then out-of-Africa has to make another assumption - and here it errs - namely that African populations lost this original state of low genetic diversity and developed more diversity than on other continents. I hypothesize, in a manner of reducing the number of assumptions, that Amerindians preserved the original human demographic profile, namely low allele diversity and low effective population size. Again, all genetic systems agree on this. I can quote respectable geneticists from 1970s onward who argued that American Indians preserve the original human population structure and that one could use them as a model for the population structure of our African ancestor. I just follow Occam's Razor by removing the assumptions of 1) Africans losing ancient levels of diversity and 2) Amerindians regaining them.

Your reasoning works like this: geneticists proved that humans evolved in Africa, Pygmies and Bushmen are the earliest offshoots, their music is similar, they are short, hence our earliest music was P/B style and our ancestors were short. All deviations from P/B style in other parts of the world are the various states of decay of P/B. This is very superficial and unconvincing.

DocG said...

German: "This is a huge assumption because it entails both the antiquity of Africans and the recency of Amerindians. You pretty much borrow answers to all the key issues of recent human evolutionary history from a different discipline. [etc.]"

1. If the consensus among geneticists, archaeologists and most anthropologists that modern humans originated in Africa offends you, then I hereby give you permission to interpret HBP as the common ancestor of pygmies and bushmen only and not the common ancestor of modern humans in general. In any case, the H in HBP stands for "hypothetical." What I'm doing is introducing a methodology that enables us to formulate meaningful, testable hypotheses. You are free to interpret it as you please.

2. As far as the genetic evidence is concerned, this is the wrong place to post your critique, as I am not a geneticist. Even if I were to agree with you that the evidence points more strongly to your Out of America theory than Out of Africa, it would mean little, because I don't have any clout whatsoever among geneticists. As things stand, I see NO evidence of ANY kind for Out of America and therefore I'm going to stick with Out of Africa unless and until that sort of evidence emerges.

3. I am not any longer going to respond to posts of yours that continue to dismiss my work simply because I am in agreement with everyone in the world but you that OOAf is far more likely than OOAm.

DocG said...

One more thing, German. If you feel so strongly that the geneticists are on the wrong track, then you should write up a critique and submit it to one of the genetics journals. Since you claim to have learned so much on this topic when you were a student at Stanford, then you should have no trouble with peer review. When your article is published, I promise to read it and also to post a link to it on this blog. Fair enough?

German said...

"I hereby give you permission to interpret HBP as the common ancestor of pygmies and bushmen only and not the common ancestor of modern humans in general."

Finally, Victor! This is a cautious and meaningful approach.

"I am not any longer going to respond to posts of yours that continue to dismiss my work simply because I am in agreement with everyone in the world but you that OOAf is far more likely than OOAm."

I'm not going to post any more comments on your OOAf ideas. I will use your publications as only pointing to a certain commonality between Bushmen and Pygmy music which may point to common origin between the two populations.

"If you feel so strongly that the geneticists are on the wrong track, then you should write up a critique and submit it to one of the genetics journals. Since you claim to have learned so much on this topic when you were a student at Stanford, then you should have no trouble with peer review."

Bill Durham invited me to write exactly this kind of paper back in 1999. He said: write this paper, there's lots of noise in mtDNA research, and then we [meaning "evolutionary biologists"] will figure out how to connect out of America to the existing taxonomy of hominins. I didn't end up writing this paper because at that time I was passionate about other things, including kinship, linguistics, comparative ethnology, philosophy, constructivism and a lot of other things. Maybe I lost my chance to revert the course of research in population genetics. Or, an opportune time is still ahead of me. With much more research available since 1999 (which brought with it lots of useful phylogeographic and archaeogenetic information, which, in my opinion, can be a decisive factor in sustaining or debunking current gene phylogenies), I feel much more enthusiastic about genetic data in general.

German said...

"As things stand, I see NO evidence of ANY kind for Out of America."

Sorry, just couldn't resist...

mtDNA and Y-DNA lineages directly related to American Indian lineages are found in widely dispersed geographic areas of the Old World (mtDNA B in Southeast Asia and Oceania, D in India and the Caucasus, X in North Africa, Middle East and Europe). A lineage identical to American Indian ones, namely D1, was found in Jomon remains in Japan (see Mitochondrial DNA analysis of Jomon skeletons from the Funadomari site, Hokkaido, and its implication for the origins of Native Americans, by Adachi). In your own post 228 you show Y-DNA C lineage as an outgroup to D and E, E being a very common African lineage. C lineage is attested in North America in Na-Dene, Siouan, Eskimo-Aleut and Muskogean populations. Y-DNA Q lineage most frequent in the Americas is also found in India.

The only attestation of a fluted (Clovis-looking) projectile point in Siberia comes from Uptar site, which is 1000 years younger than Clovis in America.

This is without even mentioning 140 linguistic stocks in America and the wealth of kinship data.

No Sub-Saharan African lineages have ever been detected in extant or past human populations outside of Africa. Africa is home to only 20 language families at best.

You can disagree on the directionality of migrations - this is your right - but how can you not SEE what I'm talking about still escapes me.