Wednesday, May 5, 2010

An Investigation into the "Mysterious" Mesolithic Maghrebi populations

The present discussion takes off from the trail of a previous one posted here on the examination of the "Mechta-Afalou" and the European "Cro-Magnons" as elements of a monophyletic unit constituting a taxonomic "type". That previous discussion had put a spotlight on the futility of such a thesis, which varied quite widely in its specifics as one went from the subjective taxonomic regime of one researcher to the next. In that same discussion, the following was noted:  "the Mechtoid concept and its supposed relationship with Cro-Magnon, is nothing more than another Eurocentric way of trying to relate North Africa to Europe...essentially a *wishful* desire to see north Africa as more an extension of Europe than the actual continent [Africa] its attached to".

Indeed, there has been a long indirectly-stated desire to make the coastal northern piece of the African continent an extension of Europe, and territory which has traditionally been THE domain of European-descended peoples than of autochthonous Africans, which are generally treated as "newcomers" to the region. In other words, some sort of a "natural" apartheid was put in place in the late Upper Paleolithic until some time in the early Holocene, preventing autochthonous Africans from inhabiting the place, while the same region was supposedly hospitable to "European immigrants". This theme blatantly makes its reappearance in another study that has fairly recently enjoyed elevated circulation and has become a citation-favorite within online 'white' supremacist cult gatherings, undoubtedly attributable to the French-published study becoming more accessible as English-translated versions became more available on the net. The study in question comes from Kefi et al., under the heading: Mitochondrial Diversity of the Population of Taforalt (12,000 years b.p. - Morocco): A Genetic Study Approach to the Peopling of North Africa, 2005.

These authors make it a point to demonstrate that their Taforalt samples were virtually untainted by "sub-Saharan" African genetic infiltration, essentially presenting a scenario whereby the supposed Taforalt "foreign settler" community were living in a virtual world of a natural apartheid, whereby the authochthonous African populations for some odd reason, steered clear from the region at all cost, which as it turns out, was at least hospitable enough for a "foreign settler" community, but not Africans themselves. This is at least what these authors, and others like them, will have people buy into. One might as well say that there was a wall of a "security beam" network barricading the entire length of coastal northern Africa from autochthonous Africans, which would burn them if they dared cross to the "other side", hence preventing them from finding a haven in coastal northern Africa and keeping them at bay in the Sahel or "sub-Saharan" Africa. The authors tell readers that essentially all but a single individual or two has possible "sub-Saharan" African ancestry, saying in the abstract that:

Genetic and anthropological studies have revealed the complexity of the peopling of North Africa. For the purpose of contributing to a better understanding of the establishment of populations in this Mediterranean region, we proposed the study of the mitochondrial diversity of the Ibero-Maurusian population of Taforalt (12,000 years - Morocco). Ancient DNA was extracted from thirty specimens excavated from the EpiPaleolithic cave of Taforalt. We amplified and sequenced the HVS1 fragment of the mitochondrial DNA control region. The genetic diversity of the population of Taforalt shows that they are not individuals related to sub-Saharan individuals. The hypothesis of a sub-Sudanese [likely a typo in the original publication, and probably meant to be read as "sub-Saharan"; however, arguing against a possible typo, is the fact that the term is used repeatedly. This notwithstanding, one can't help but get the impression that this word is treated as if it were synonymous with "sub-Saharan African"]  origin of the Ibero-Maurusian males is rejected. Our results are consistent with a local origin of the population of Taforalt and genetic continuity in North Africa.

While the authors speak of a "local origin" of the EpiPaleolithic Taforalt group in question, this should not be mistaken for a purely autochthonous African origin in its coastal areas in the north, as 1) any autochthonous African population would have to be related to "sub-Saharan" populations, even if they don't descend from some established group of the latter but ultimately draw from common ancestral gene pools specific to Africa, and 2) the authors go onto tell the reader that pretty much "all the sequences of the Taforalt specimens display haplotypes belonging to Eurasian haplogroups", which going by even their own report, is a stretch of the real state of affairs, whatever the degree that one might reckon it to be:

The 21 specimens analyzed are sufficient to give a good idea of the characteristics of the Taforalt population. None of these specimens are related to the actual sub-Sudanese specimens (lack of haplogroup L, that groups haplotypes typically Sub-Saharan African). The hypothesis of an origin of Ibero-Maurusians south of the Sahara is therefore not supported by our results, showing a population of Mediterranean type rather in the North of Africa at least until 12.000 years. Our results support work based on dental, cranio-facial morphometrics and post-cranial analysis showing divergences between Ibero-Maurusian populations and their contemporaries in Sudan (Bermudez de Castro 1991, Irish 2000).The presence of a sub-Saharan component in the actual north African populations is likely attributable to migrations later than 12.000 years BP.

All the sequences of the Taforalt specimens display haplotypes belonging to Eurasian haplogroups. Among the haplogroup majority, H is considered as originating in the Near East, the emergence of this haplogroup dated to about 35,000 years, while haplogroup JT, also originating in the Near East, has an age of up to 50,000 years; finally, the native haplogroup U6 of northern Africa is purposed as being contemporary with haplogroup JT.

When the authors say above that "none" of their Taforalt specimens were related to "sub-Sudanese", likely a euphemism for "sub-Saharan" Africans, they were not being frank, according to specifics of their very own report. From the rather ambiguous assignments that they provide the reader throughout their report, it is estimated that at least one specimen could very well be a carrier of a hg L marker. The remains of this one individual with plausible "sub-Saharan" African ancestry, appears as follows:

*Click on all images for greater resolution.

This individual—designated as Taf VIII—apparently displays the usual host of cranio-facial characteristics that Eurocentric-minded folks have traditionally attributed to the "caucasian" archetype, yet we are passingly alerted about the very real possibility that individual could well have been a carrier of the hg L marker, which as posted above, the authors essentially equate with "sub-Saharan" Africans. This fellow will have not looked out of place with the rest of the group, whom we are told, were generally carriers of "Eurasian" mitochondrial markers; not at all. Why is this important? It is only significant to the extent that such canio-facial manifestations had formed the basis for preconceived nationalistic-driven Eurocentric arbitrary taxonomic constructs like "Caucasoid" , "Mediterranean", "Negroid", etc, whereby the "Caucasian" or "Caucasoid" taxonomic unit is supposed to embody a standalone monophyletic taxonomic unit, specifically as one "race" among the several human "races". This basic ideology is what has plagued coastal northern African paleontological record, and even why we are having to discuss topics such as the one at hand. These cranio-facial features have prompted several advocates to treat coastal northern Africa as the traditional bio-historical domain of "Caucasians", ultimately from Europe and/or the so-called "Near East", that only relatively recently, got infiltrated by people from south of the Sahara. This very idea is in fact bluntly stated in the extract cited above; one need not go too far, to look up an example. Honestly, if the cranio-metric patterns of these EpiPaleolithic northern Africans were deemed to have stereotypical "Negro" traits, would we be having this discussion; would Eurocentric ideologues be just as eager to mystify them and entertain the idea that they could have been "European" emigrants; would we be having people like Kefi et al. saying that they had no relationship with "sub-Saharan Africans" and that the bulk of their mtDNA markers are "Eurasian"? Something to definitely think about.

Meanwhile, as noted moments ago, the integrity of Kefi et al.'s mtDNA-sequence reports is hampered by several noticeable loose ends that need to be ironed out, not the least of which is the glaring extreme ambiguity. Caramelli et al. [2003, 2008] who go out of their way to brief the reader on their even more meticulous quality control measures [than those supposedly taken by Kefi et al.] to ensure authentic DNA reporting, still suffered informational inadequacies, let alone that of Kefi et al.'s comparatively far less stringent quality control regime. Indeed Kefi et al.'s confession about having to grapple with DNA contamination meets expectations, given the insufficient quality control measures detailed by them. DNA of their DNA handling crew infiltrated that of several of the PCR fragments, generating sequences similar to those of the DNA crew members. Of course, Kefi et al. reassure their readers that this problem was subsequently contained, claiming to have shelved the affected specimens, and relieved them of any further analytical use. Who is to say that other contaminating exogenous DNA did not infiltrate sections of the remaining DNA fragments? After all, one or a couple of sequences [16126C and 16355T for example] named in the contaminating DNA also reappeared in several other DNA sequences, aside from the three specimen fragments eliminated from the analysis.

In fact, while the authors proclaim to presumably gotten around to correcting the mutational artifacts of exogenous influences, the following revelations point to unnatural mutations that made their way into the PCR fragments:

Table 7 groups the polymorphisms observed for 23 specimens, mutations in this table are checked several times on different sequences. The mutations are considered authentic when they are found on independent PCR [fragments] of two different DNA extractions performed on the same specimen. In certain cases we noticed for the same individual, different sequences from PCR of independent extractions. As regards the specimen Taf V-18 for instance, mutations 16126C-16304C-16311C are spotted on the sequences of two independent products of PCR, acquired from a first extraction, while for the second extraction, mutation 16311C is not found. So sequence considered for the specimen Taf V-18 is the following: 16126TC-16304C. The non-reproducibility of certain mutations is also observed in the case of specimen XXIV Taf (Table 8). Indeed, the 16129A mutation is observed only once, it is therefore excluded.

The investigation of the specific root cause of these exogenous and inconsistent sequences from the very same specimens seem to have been brushed aside, and instead, the authors hoped to get around the problem by simply eliminating sequences that don't repeat themselves in the PCR products of two "independent" DNA extractions from the same specimen. If repeated contamination somehow excluded one or another contaminating sequence or mutation in one or the other of the two "independent" extractions from the same specimen, how would that have then been remedied by the authors, short of simply eliminating a sequence that does not reappear in one of the two "independent" DNA extractions? These inconsistencies are reflective of intrusive foreign DNA elements in the affected DNA extractions of designated individual specimens. It should be noted that the authors named three specimens earlier, which they told the reader that they eliminated from the analysis due to "contamination" of DNA from exogenous DNA from the research crew; these were namely, specimens Taf VIII-18, Taf XVII-2, and Taf XVII-3. Interestingly, samples from these very same three specimens reported larger-than-average [particularly, for ancient DNA fragments] quantities of replicated DNA strands, as the authors themselves admit, as follows:

For all successful PCR, the quantities of estimated DNA amplifications vary from 5 to 15 ng per 8 μl of product of PCR deposited on agarose gel. Except for for the three specimens Taf VIII-18, Taf XVII-2 and Taf XVII-3 for which the quantity of DNA estimated is from 20 to 30 ng (per 8 μl of product of PCR deposited on agarose gel). These quantities are two times the amounts normally obtained by amplifying ancient DNA. In addition, the PCR products were obtained at the first attempt of amplification reaction. These findings resemble those observed during the amplification of recent DNA [of the research team members], suggesting contamination with recent DNA.

The three above-mentioned were eliminated from further use; yet PCR products from the same specimen but of two "independent" PCR trials with inconsistent sequences were retained for the final analysis. Could it be because, if these items too were eliminated, then the authors would have been left with very little DNA material to work with?  

The authors point out:

Could the determination of the sequences of the specimens of Taforalt resolve the problem of the nomenclature of the subjects of this ancient population?

Taf V-5, Taf V-18 and Taf V27 have different mitochondrial sequences (Picture 7). These are therefore of distinct individuals. So, the Arabic numeral points out the number [specimen designator] assigned to subject buried in the burial. This is confirmed by the analysis of the sequences of Taf XXV-3 and Taf XXV. These last specimens have different polymorphisms (Picture 7), and therefore those of two different subjects. Specimens Taf V-5, Taf V-7 and Taf V-20 have the same mitochondrial sequence. Buried in the same burial, these three specimens could have links of consanguinity according to the maternal line. For studying the mitochondrial diversity of the Taforalt population, we adopted the same selection criteria as those we use in the study of the recent populations, and therefore excluded the related individuals.

Thus we considered a single sequence among those of the three specimens: Taf V-5, Taf V-7 and Taf V-20. We then have the sequences of 21 specimens instead of 23. The sequences of these 21 specimens represent 13 different haplotypes.

The authors started out with 31 EpiPaleolithic specimens, and they tell the reader that they were left with working with 26 specimens after eliminating certain named specimens for one reason or the other, which was then reduced to first 24 and then 23 specimens. Yet, we come to learn that the even those 23 specimens were reduced further down to just 21 specimens that were used in the final analysis. In the above, the authors named yet another two specimens, both alleged to be closely related to one specimen retained in the final analysis; the names of the three related specimen were given above as follows; Taf V-5, Taf V-7 and Taf V-20. One of these, we are not told specifically which one, was to have been considered in the final analysis, while the other two [again, we are not told which two of the three closely related specimens] would have been eliminated from the study.

Perhaps a relatively minor issue, it is of note that Taf V-5's and Taf V-20's  fragment sequences start earlier and end earlier than that of Taf V-7, with the former's sequences between positions 16054 and 16317 having been compared against those of the Cambridge Reference Sequence, while the latter's was read from 16081 and 16404; what if mutations in positions prior to 16081 in Taf V-7's case and after 16317 in either Taf V-5's or Taf V-20's case were different from those of either Taf V-5 or Taf V-20, and V-7 respectively; could there be mutations here that could drastically alter what the authors would call the "most likely haplogroups" that these specimens' markers fall into? Something to ponder, but at any rate, along with the earlier named three contaminated specimens, the aforementioned two closely-related specimens would have amounted to five specimens being eliminated, reducing the 31 specimens down to 26. However, the authors provide the reader with a table consisting of 23 individual specimens, and all three of those closely related individuals were in it! What they did not tell the reader, nor did they identify them by name or tag, and hence, possibly leaving an unsuspecting reader scratching his/her head, is that five more specimens were excluded from the study, which were not included in the aforementioned table. These undeclared left-out specimens are namely; Taf VI-9, Taf XVII-18, Taf XIX-7, Taf XXI, and Taf I—missing specimens not named! The reader is not offered explanation on why these were not made part of the study, and so left on his/her own, to wonder what might have been wrong with them. They could have been damaged, degraded or contaminated; any or a combination of any of these could have affected sequences of those specimens. Had the authors therefore eliminated those aforementioned specimens with inconsistent and therefore dubious sequences, they would have been left with fairly small amount of individual DNA material to work with, and even then, the results would not be unequivocal, given that a good deal of their overall sample size would have been purged from the final analysis; the integrity of the so-called "good" DNA would have been put to question as well. Through it all, the authors could not even get themselves to firmly assign the sequences into a specific haplogroup set.

Several of the variant hypervariable segment positions noted for the different sequences, and therefore offered as some sort of haplogroup vetting-gauges, thereby narrowing assignment of said sequences down to one or couple of suspected haplogroups, turned out to be types that are actually shared across different super-haplogroups. One wonders if some of the sequences could well not be artifacts of exogenous mutations, like those accompanied by hydrolytic deamination, upon the prospect of further investigation.It may well boil down to a matter of a select combination of designated mutations rather than standalone mutations that provide a better measure of pinning down the most likely haplogroup at hand, but those shared mutations across different super-haplogroups in of themselves offer little use in predicting the most likely haplogroup that a specimen falls into. To demonstrate with examples, let's take Kefi et al.'s use of the HVRI segment position "16126C". Now these authors use this mutation to predict specimen Taf XXV 3's most likely assignment into haplogroup JT.

The transition 16126C on its own offers little in way of predicting the most likely haplogroup-affiliation since its presence spans multiple super-haplogroups; for instance, the presence of this transition could just as well make either of the super-haplogroups L3 and L1 the most likely lineage of specimen Taf XXV 3, and yet, Kefi et al. personally preferred to single out haplogroup JT, for an identification with hg L3 or hg L1 would contradict the authors' stated position about the lack of maternal relationship between Taforalt specimens and sub-Saharan Africans. Similarly, specimen Taf 55-IB supposedly reported the mutation represented by position "16239T". The authors subjectively preferred hg H as the most likely haplogroup lineage of that specimen, yet the same specimen could just as likely belong to either hg L2 or hg L3. Although the combined presence of "16126C and 16355T" could be relatively rare in the mitochondrial organelle bearing African-specific hg L lineage, both these mutations have occurred more than once in the African hg L gene pool, and so, it is not inconceivable that a specimen, Taf 55-I in particular, could just as well fall into either an African-specific hg L3 lineage, hg L2 lineage, hg L1 or possibly L4. The cases of heteroplasmy that the authors observed simply compound the uncertainty of their haplogroup assignments. Kefi et al.'s heteroplasmic mutation of "16298 T/C" reported for specimen Taf V 27, could just as well assign that specimen's lineage into hg L3, where the individual 16298C mutation is known to occur. In relation to this, the combined presence of "16179T and 16298T/C" could well assign Taf XIX a into haplogroup L3, wherein both mutations occur in L3h1 sister lineages, even though Kefi et al. gave their personal liking to hg V as the possible haplogroup; hg L1 could be a relatively more distant possibility, wherein the mutation 16179T also occurs. "16124T/C" and "16239T" could readily place specimen "Taf VI-10" in hg L3.

The positions "16172C" and the aforementioned "16126C" could place a specimen (Taf XXIV) in a rare L3h1b1 marker, and likewise, Taf V19E in either some L3h1b1 derivative, L1a subclade, or even M1 subclade, which all have variants bearing the 16172C mutation, assuming that Kefi et al.'s reports for either specimens doesn't involve exogenous mutations, and that homoplasic mutational events took place across hgs L3h1b1, L1a, U6, M1 and possibly, per Kefi et al.'s reckoning, JT in the HVR1 control region. The individual "16233T" mutation occurs frequently in different African-specific L type super-haplogroups, though it also occurs within M and N sub-haplogroups to a comparatively smaller degree. This could place Taf VIII in either of these super-haplogroups. That several of these alternatives had not been considered by Kefi et al., especially where singular or duo "characteristic" mutations are concerned, suggests that the authors could not resist cherry-picking in order to align results with a preconceived perspective. Moreover, Kefi et al. rely too heavily on the HVR1 section of the mitochondrial genome, which is prone to homoplasy across divergent monophyletic units, and on a inadequate number of selections at that. Is it any wonder then, the authors couldn't even firmly discern if certain markers were hg U6, hg JT, or if certain markers belonged to hg U or hg H; likewise, they couldn't discern whether certain markers were to be placed in hg L, M or N. Indeed, one even questions how much faith the researchers themselves placed on their findings as each and every such assignments was followed up with a question-mark!

Even the figures that the authors post in relation to specific haplogroup components doesn't add up, in light of the ambiguity characterizing their specimen assignments to lineages; they note:

42.8 % (9/21) of the Taforalt population have a sequence identical to CRS (Cambridge Reference Sequence, Anderson and al. 1981) reference sequence. These specimens could be classified in haplogroups H or U. Four specimens (19 %) of the Taforalt population have the 16126C mutation. These haplotypes might belong to haplogroup JT. The polymorphisms observed for specimens Taf 55-IB, Taf V26, Taf VI-10 and Taf XVI a2-19 (4/21-19 %) orient the classification of their haplotypes in haplogroup H.

Two specimens of the Taforalt population: Taf XXIV and Taf VI9E (9.5%) have the 16172C mutation in their sequence. Taf VI9E and Taf XXIV could be classified into haplogroup U6 (Maca-Meyer et al. 2003). Specimen Taf VIII has a sequence that differs from the reference sequence (CRS) by the substitution 16223T. The haplotype of this specimen may belong to haplogroups L3, M or N. Two specimens (9.5%) of the Taforalt population could be classified into haplogroup V. We observed the presence of three cases of heteroplasmy (Taf VI-10, Taf V-27, Taf XIX). These heteroplasmies concern positions 16298 and 16124 where we clearly observed the superimposing of the curve of the nucleotide T with the curve of the nucleotide C (to see chromatogram in Figure 4).

The figures given by the authors above, by way of distinct designated individual nucleotide positions, inadvertently head-counts at least one individual twice, unsurprisingly—which amounts to the authors having confused themselves by the ambiguity of their very own specimen assignments into haplogroups, wherein the same individual was counted for both hg JT and hg U, instead of either one of these two haplogroups but not both of them at the same time! This resulted in the authors counting specimen Taf XXIV for both hg JT and hg U6 at the very same time, thereby assigning "4/21" individuals into hg JT and "2/21" individuals into hg U6.

While Kefi et al. claimed to have used all the necessary precautionary measures in their DNA extraction and amplifications thereof, the above-mentioned issues of contamination, ghost-mutations, and the elimination—which itself was a fairly conservative choice on the authors' part, as other specimens which were plagued with questionable and inconsistent sequencing reports, by authors' very own admission, were not put aside—of a good chunk of the original sample size put to question, the overall informative integrity of the study, and they demonstrate that the quality control of the DNA analysis was not meticulous enough, not leaving out the fact that the authors' results thereof were not duplicated in two or more different labs by different research teams.

The authors made quick references to other disciplines whose findings they claim that their results reinforce, such as that of cranial and post-cranial analysis. They claimed that data suggests that "Mechtoid" characters did not completely disappear but were found in 3% of Maghrebi populations and "higher" in Canary Island populations, citing old anthropological works...

Our results reinforce the anthropologic suggest that human type Mechta el-Arbi has not disappeared completely. The characters are méchtoïdes found in 8% of protohistoric burials, in 3% of current populations of the Maghreb and higher percentage among island populations Canary (Ferembach 1962 Camps 1989). Our results give weight to the dentistry, and lithic, craniometric suggesting regional continuity North Africa since the Pleistocene terminal (Lubell et al. 1984, Irish 2000).

Brace et al.'s cranial analysis from the same year, 2005, head on contradicts Kefi et al.'s position, wherein they note, as cited herein before, that:

It is clear, however, that they [the Basques] do not represent a survival of the kind of craniofacial form indicated by Cro-Magnon any more than do the Canary Islanders, nor does either sample tie in with the Berbers of North Africa as has previously been claimed (37, 44-45)... 

To test the analysis shown in Fig. 3, Cro-Magnon, represented by the x in Fig. 4, was removed from the European Upper Palaeolithic sample and run as a single individual. Interestingly enough, Cro-Magnon is not close to any more recent sample. Clearly Cro-Magnon is not the same as the Basque or Canary Island samples.

In a plot wherein the original "Cro-Magnon" specimen, the "Old Man", was run separately from other Paleolithic European specimens, the recent Maghrebi populations are visibly quite distant from both the said Cro-Magnon and the EpiPaleolithic Maghrebi specimens; see:


Note the positions of Cro-Magnon I, the Algerian Neolithic, the pooled "Taforalt and Afalou", the recent Algerians, Tunisians, and a pooled "Berber" sample.

Kefi et al. reference Irish (2000) presumably to buttress their claim that the EpiPaleolithic Moroccan specimens were not related to "sub-Saharan" Africans. Irish himself, in the work "The Iberomaurusian enigma: north African progenitor or dead end?", 2000, claims:

Iberomaurusians from Taforalt in Morocco and Afalou-Bou-Rhummel in Algeria, Nubians from Jebel Sahaba in Sudan, post-Pleistocene Capsians from Algeria and Tunisia, and a series of other samples were statistically compared using 29 discrete dental traits to help estimate diachronic local and regional affinities. Results revealed: 

(1) a relationship between the Iberomaurusians, particularly those from Taforalt, and later Maghreb and other North African samples, and (2) a divergence among contemporaneous Iberomaurusians and Nubian samples. Thus, some measure of long-term population continuity in the Maghreb and surrounding region is supported, whereas greater North African population heterogenity during the Late Pleistocene is implied.

Similarities in dentition between the Maghrebi specimens is understandable when one considers similarities in the socio-economies of the different contemporaneous EpiPaleolithic and early Holocene groups of the Maghreb, likely brought about by acculturation due to relative geographic proximity and through possible interactions. The same applies to the chronologically later so-called "Capsian" groups of Algeria and Tunisia, who could have attained certain cultural influences from "Ibero-Maurusian" groups of those regions, like for example, the dental mutilation of the front incisors; this tradition is noticeably less frequent in the "Capsian" groups than the "Ibero-Maurusian" groups, but occurs there nonetheless. Still, similarities in dental traits has no bearing on cranio-metric revelations that said coastal northwestern specimens do not form some homogeneous cranial type, which a number of researchers had been compelled to acknowledge, despite attempts to force them into a preconceived taxonomic type(s) spanning several of some or the other of the groups that Irish mentions above.

For instance, as pointed out here before, Briggs came up with four "types" from his analysis of EpiPaleolithic and early Holocene Maghrebi specimens [including the so-called "Ibero-Maurusians" and so-called "Capsian" groups], three of which were described as "Mediterranean" sub-types, while the remainder was reckoned to be a mixture of these "Mediterranean" sub-types; these "types" were named respectively as follows: "Type A", "Type B", "Type C", and "Type D".

Chamla on the other hand, came up with two primary "types" and a derivative type namely, the "Mectha-Afalou", the "Mediterranean" types (the "Proto Mediterranean"), and the "Mechtoids" respectively. The "Mechta-Afalou" were associated with the "Ibero-Maurusian" industry, while the latter two were associated with the "Capsian" industry, with the Mechtoids being representative of the Upper Capsian industry [which is interesting, considering that Chamla saw them as the "gracile" version of the "Mechta-Afalou" type, whom as noted, had been associated with "Ibero-Maurusian" industry]. The "Mechta-Afalou" were considered to be generally more robust than the latter Capsian groups.

Recalling another example, noting differences in the EpiPaleolithic and early Holocene cranial collection, see:


As we can see in the above, estimation is made that both specimens (which had all been indiscriminately brought under the "Mechtoid" banner) with no supposed discerning "Negro" qualities and those with "Negro" qualities had been found specimens extending from the Maghreb to Sudan. The questions that arise from these observations, is that if the specimens in question represented Europeans presumably from the Iberian region, then are we to assume that they were responsible for spreading the just-mentioned diversity to fairly far flung areas from their Iberian point of origin, extending all the way to the eastern corner of Africa—i.e. as far as Sudan, having been able to successfully crossover from the Sahara to the Sahel, yet at the same time, autochthonous Africans somehow could not crossover the Sahara and penetrate the Maghreb; are we to assume that sections of these "Iberians" naturally had "Negro" cranio-metric qualities about them, while others hadn't? If not, then how would the "Negro" cranio-metric qualities have been attained? Yet, how is it that despite such dichotomy [between "Negroid" and "non-Negroid" qualities] in the so-called "Mechtoid" samples, some insist that these specimens represent a taxonomic type? And for those who might insist that only the "non-Negroid" specimens represented the "Iberian" immigrants, it should be noted that even those so-called "non-Negroid" elements are in of themselves clearly quite varied. This leads to the question: Where does one come across the same variety in the Iberian peninsula itself, presumably predating the African examples, as that which was supposedly put in place by a would-be "Iberian settler" immigrant community(s) in northern Africa? Likewise, what cultural precedents of the so-called Mechtoid varieties extending from Taforalt to Jebel Sahaba does one find in Iberia? And by "culture" here, reference is being made the culture in its wholesome, as opposed to just some isolated superficial parallels in a few stone tools here and there. These questions are generally greeted with much silence, yet one does not cease to come across those who speak of EpiPaleolithic Maghreb being the exclusive territorial domain of some "Iberian" settler community.
 
The excessively long history of anatomically modern human occupation of the Maghreb predating the emergence of the so-called "Ibero-Maurusian" populations shatters Eurocentric myths about EpiPaleolithic Maghrebi specimens representing some "Iberian" settler community that would have been isolated from autochthonous Africans from "sub-Saharan" Africa. Certainly, the Aterian populations do not represent a European settler group, nor do those from the Irhoud sites. Both the Aterian and Irhoud individuals are deemed to be "modern humans", although still retaining a few so-called "plesiomorphic" traits. If these folks did not come from Europe, as all indicators point out, not to leave out the fairly obvious one, which is that their presence in the Maghreb even predates the settlement of Europe by anatomically modern humans, then surely the source of these humans would have had to have been "sub-Saharan" Africa. Some try to lend some modicum of rationality to north African "Iberian" settler-group, by speaking of their supposed LGM (Last Glacial Maximum) arrival, and hence, the reason for their presence in northern Africa—i.e. the Maghreb serving as a LGM refuguim.

Obviously, the Aterian specimens are certainly not representative of such immigration, since they are associated with Maghrebi complexes that predate the LGM, nor are the EpiPaleolithic so-called "Mechtoid" specimens, which are generally dated onwards from a period when the LGM was winding down.

Several publications have noted archeological and/or temporal gap between the Aterian groups and the EpiPaleolithic "Ibero-Maurusian" ones in the main locations where the former had been identified; this time gap would essentially cover nearly the entire period of the LGM! The only location where such archeological/temporal gap between the two groups is filled with continuous occupation, as an exception, is the Haua Fteah cave in Cyrenaica, Libya; this has been predicated on the understanding that layers extending from recent era through to the EpiPaleolithic paleontological series, and thereafter, through the Upper Paleolithic Dabban industry to the Libyan pre-Aurignacian complex ("Mode 4 industry") and then the more older Paleolithic periods [i.e. the Levalloiso-Mousterian/Aterian Paleolithic industry], had all been identified respectively at the Haua Fteah site. It is more than questionable that such paleontological and archeological record has its precedence in the Iberian peninsula.

Aterian cranial specimens from Dar es-Soltane are generally reflective of the upper layers (chronologically more recent layers) of the Aterian industry, but here are some images of at least one specimen—Dar es-Soltane 5; Dar es-Soltane 5 [left/top] and Dar es-Soltane 5 sketch [right/below]:



Immediately above, is a "Capsian" site skeletal remain; note the missing incisors, and compare its nasal opening with the Aterian specimens above, and also the following Taforalt specimen.

At a glance, the nasal widths of these specimen (Aterian specimens in particular) appear moderate, if not considered to be "narrow", and not too far off from the Taforalt specimen posted earlier [also shown below]—Taf VIII:


Taf VIII's nasal opening certainly does not give an impression of a low bridge and wide nose. Given a look at the nasal openings of both the Aterian individuals and that of the Taforalt specimen, the latter's (the Taforalt specimen) example does not appear to be inconsistent with the Saharan patterns throughout that regions entire paleontological history.

Nasal opening aside, note the Aterian specimens more robust traits, notably for example, the brow ridges.

Finally, the issue of the post-cranial data that Kefi et al. note in a passing: Perhaps these authors were alluding to findings like this, by T. Holliday, which suggest differences between the Jebel Sahaba specimens and the Mesolithic "Ibero-Maurusian" specimens.

Body proportions of the Jebel Sahaba sample.

TRENTON W. HOLLIDAY1.

1Department of Anthropology, Tulane University. 

The Epipaleolithic site of Jebel Sahaba (Sudan) was discovered in 1962, ca. 1 km from the east bank of the Nile, and ca. 3 km north of Wadi Halfa (the site is now submerged beneath Lake Nasser/Nubia). From 1962-1966, a total of 58 intentionally-buried skeletons were uncovered at the site. Diagnostic microliths suggestive of the Qadan industry as well as the site’s geology suggest an age of 14 – 12 ka for these burials. In this study, the body proportions of the Jebel Sahaba hominins are compared to those of a large (N = ca. 1100) sample of recent human skeletons from Europe, Africa, and the north circumpolar region, as well as to terminal Pleistocene “Iberomaurusian” skeletons from the northwestern African sites of Afalou (Algeria) and Taforalt (Morocco), and Natufian skeletons from the southern Levantine sites of El Wad and Kebara. Univariate analyses distinguish Jebel Sahaba from European and circumpolar samples, but do not tend to segregate them from North or Sub-Saharan African samples. In contrast, multivariate analyses (PCA, PCO with minimum spanning tree, NJ and UPGMA cluster analyses) indicate that the body shape of the Jebel Sahaba hominins is closest to that of recent Sub-Saharan Africans, and different from that of either the Natufians or the northwest African “Iberomaurusian” samples. Importantly, these results corroborate those of Irish (2000), who, using non-metric dental and osseous oral traits, found that Jebel Sahaba was most similar to recent Sub-Saharan Africans, and morphologically distinct from their contemporaries in other parts of North Africa. This study was funded in part by NSF (grant number SBR-9321339).

Both the "Ibero-Maurusian" specimens and the Jebel Sahaba specimens generally have tropical body proportions, or else a fairly sizable segment of their sample sizes bear such proportions, where limb and/or trunk-limb proportions are concerned. Perhaps a hint on this in the above extract, is the fact that Jebel Sahaba could not be segregated from either the "Ibero-Maurasian" and the recent "sub-Saharan" African samples through the "univariate" analysis; whereas it was effectively distinguished from the recent European and circumpolar samples. It is possible that the parameters for body linearity or mass may well have placed either the Natufians and the "Ibero-Maurusian" samples in "intermediate" ranges. Should this be the case, the finding would contradict Kefi et al.'s supposition about a lack of relationship between the Taforalt specimens and "sub-Saharan" Africans, be it tentative evidence of the Taforalt populations exchanging genes with geographically proximate "non-African" groups, or micro-evolutionary response to the sub-tropical environment near the Atlas Mountain chain region. Certainly the Natufians are no stranger to being recognized as at least immediate partial descendants of Africans, ultimately from "sub-Saharan" Africa. Recalling Holliday's work here, the Upper Paleolithic European specimens differed from the later Paleolithic Europeans, in that the latter, while still retaining tropical body proportions, developed shorter limbs, thereby reflecting change, likely brought about the extreme cold temperatures associated with the last glacial periods. The remains of Taforalt specimens, on the other hand, are reportedly suggestive of tall individuals; rarely do tall individuals exhibit "shortened" limbs.

According to material referenced by Hershkovitz et al. 1995, the limb-proportion means of a pooled EpiPaleolithic northern African sample fell right within the tropical African range [85% for crural index and 77% for brachial index]. Now, since this is a pooled group from a wide geographical expanse, spanning that from Jebel Sahaba to Moroccan territory—i.e. west to east or vice versa, which had all previously been indiscriminately included in the so-called "Mechtoid" taxonomic-construct, it might well be instructive to keep in mind that this pooling would naturally affect the overall mean. The individual indexes actually ranged from 82-88. More of the individual Jebel Sahaba samples are inclined to be in the higher-end ranges of the pooled samples with greater probability than those of their Maghrebi counterparts, considering that aforementioned data on "multivariateexamination on body shape, and the former's relative geographical proximity to the tropical areas. Obviously, 82% index is an example of a low value generally out of the range of the tropical African mean, but in order for the mean to be within the range of the tropical African mean, there would have had to have been enough individual indexes in the pooled sample with great enough values, so as to bring the average to the stated value, which is similar to one that Holliday observed for "sub-Saharan Africans" elsewhere; see: Body Proportions—Trenton W. Holliday - 3

It is not inconceivable that Mesolithic Maghrebi groups [who do not appear to be ancestors of recent Maghreb Tamazight or "Berber" speaking groups based on cranial findings and genetic material] may have interacted and exchanged genes with geographically proximate groups that "back-migrated" into the African continent, just as the case seem to be in that region today, though evidence is wanting in that regard, but the idea that they were "isolated" settler immigrant groups untainted by genetic exchange with autochthonous Africans, particularly "sub-Saharan" Africans, is unsupported by the preponderance of available evidence, both from an archeological and bio-anthropological standpoint. As it stands, the burden lies on advocates proposing thereof,  to present substantive multidisciplinary evidence that unquestionably establishes EpiPaleolithic Maghrebi as nothing more than settler immigrant "Europeans"!

*Keep an eye on possible updates in future. Update posted 4/16/2013 (see link below).

 Update and additional information!

________________________________________________
*References:

— Kefi et al. (2005), Mitochondrial Diversity of the Population of Taforalt (12,000 years b.p. - Morocco): A Genetic Study Approach to the Peopling of North Africa.

Hershkovitz et al. (1995 ), Ohalo II H2: A 19,000-Year-Old Skeleton From a Water-Logged Site at the Sea of Galilee, Israel

—Caramelli et al. (2008), A 28,000 Years Old Cro-Magnon mtDNA Sequence Differs from All Potentially Contaminating Modern Sequences

—Brace et al. (2005), The questionable contribution of the Neolithic and the Bronze Age to European craniofacial form

—T.W. Holliday (1999), Brachial and crural indices of European late Upper Paleolithic and Mesolithic humans.

—Personal notes: 2006, 2010.

*Further reading: Following Trails of the Cro-Magnon

14 comments:

Too Tall Jones said...

Another magesterial roundup. One wonders if the "peer reviewers" cast a critical eye on the assumptions in the Tafo study.


You say:
?As it stands, the burden lies on advocates proposing thereof, to present substantive multidisciplinary evidence that unquestionably establishes EpiPaleolithic Maghrebi as nothing more than settler immigrant "Europeans"!"

Alas, too often said burden is not carried. Instead shaky assumptions are repeated across multiple shaky studies, who then cross-reference each other- an embedded system of distortion and misleading information. Keep up the good work in exposing these shaky assumptions and methods.

PS: You had a graphic for a table 3. What study is that from?

Too Tall Jones said...

How do you see the claim by harich 2010:
"Sub-Saharan people did not leave traces in the North African maternal gene pool for the time of its settlement, some 40,000 years ago."

They claims said subsaharans are virtually missing from North africa until the recent slave trade.

Mystery Solver said...

Too Tall Jones writes:

How do you see the claim by harich 2010:
"Sub-Saharan people did not leave traces in the North African maternal gene pool for the time of its settlement, some 40,000 years ago."

They claims said subsaharans are virtually missing from North africa until the recent slave trade.


The claim seems very questionable, having given a detailed account of anatomically modern human paleontology in the Maghreb that substantially predates anatomically modern human occupation of both Europe and the rest of Asia. In the case of Kefi et al. (2005), I've also spelled out several strange genetic conclusions they make. I'll have to read the specific publication that you mention in its entirety, to make an informed assessment about the efficiency of their DNA sequencing reports, but the idea that sub-Saharan gene flow would have been absent until the "Slave-trade" is negated by the stratigraphically-deep paleontological record of the region, which includes remains of juveniles [if "sub-Saharan" originated women were not available in the region that far back then, how were these populations able to have children and leave skeletal evidence of it; there were no anatomically modern humans in Europe that far back, let alone female ones LOL? Anatomically modern human record only starts to appears in Europe at around 30,000 to 35,000 years ago or so, according to most research estimates of the specimens recovered there], along with well-noted distribution mtDNA markers like M1 in the Maghreb [and not just M1 sub-clades, but rather, the basal clades of hg M1], which have been correlated with the spread of Afrasan (Afro-Asiatic speakers)] and ancient hg L markers, not to leave out those ancient hg L markers that have been found in Iberian populations which are determined to be internally distinct from the African downstream sub-clades and too ancient to be linked with the Slave-trade!

Too Tall Jones writes:

PS: You had a graphic for a table 3. What study is that from?

I am not sure what table you are referring to; was it mentioned in the topic at hand, or was it some other? Please clarify.

Too Tall Jones said...

It was table 3: right after you mentioned Chamla"

"Recalling another example, noting differences in the EpiPaleolithic and early Holocene cranial collection, see:"
[then the Table/Image was shown)

--------------------------------

A few questions if you have time:


1) What do you make of the diagram from Salas 2003, below linked, which shows most North African mtDNA as either M1 or "L" group. with minor U6? Is this more or less accurate? And what about the date discrepancy Keita criticizes in the recent Manchester conference- U6 emergence is held by some to range well into 66kya, but according to Nati Geog's Genographic Project, humans only left Africa 60kya, creating a logical impossibility of "reutrning' Africans predating those who had not even left the continent yet. Is this basically reasonable statement of the date discrepancy issue or is their inaccuracy?

http://africanamericanculturalcenterpalmcoast.org/historyafrican/nneafricamtdnasalas1.jpg


---------------------------

2) Also what is the basic breakdown of mtDNA in Egypt? The Gurna study by Stevanovich seems to show almost 50% "L" or "M1", while the Siwa study of Coudray 2008 holds that Siwa affinity is with sub-Saharan groups. Is this more or less a reasonable breakdown or is data missing from other studies of Egyptian mtDNA?

Thanks in advance.

Mystery Solver said...

1) Too Tall Jones writes:

It was table 3: right after you mentioned Chamla"

"Recalling another example, noting differences in the EpiPaleolithic and early Holocene cranial collection, see:" [then the Table/Image was shown)


I get your query better now. I should have been clear about where it was discussed before, so as to point the reader to the source of the cited piece. The piece is actually an online translated version of the original Spanish-written version. The study in question was from as follows:

Para conocer al hombre: Homenaje a Santiago Genovés a 33 años como investigador en la UNAM, by Santiago Genovés, Universidad Autónoma de México Instituto de Investigaciones Antropológicas, 1990.

*Hope that bit of information helps.

2) Too Tall Jones writes:

1) What do you make of the diagram from Salas 2003, below linked, which shows most North African mtDNA as either M1 or "L" group. with minor U6? Is this more or less accurate?...


http://africanamericanculturalcenterpalmcoast.org/historyafrican/nneafricamtdnasalas1.jpg


The map apparently details the African-specific genetic components found in the samples referenced in the study. Note that some studies also re-report DNA frequencies from other *independent* research, of which authors of the former studies may or may not be participants. The map looks to be zeroing in on hg L, M1 and U6 distribution patterns, which *could* suggest that these markers were the central focus of the study to the possible exclusion of other types. There is nothing wrong in that, and therefore the gene pools have been reasonably described, when the proper context is understood. Of note, is the pooling of the coastal regions of Northern; naturally, this will hide the gradients of the specified individual markers or lineages described for that region. For instance, many studies have reported distinct patterns between the presumed "Eurasian" components in the Maghreb and those in Northeastern Africa, with the latter generally reporting better preserved African-specific uniparental components, which is significant, considering the latter's proximity to the so-called "Near East". Still, caution is warranted, as Cherni et al.(2005) appropriately advice, when approaching Maghrebi samples; too often, they are taken from a few spots in the far western edges of the Maghreb, particularly near the Atlas mountain range, and rarely comprehensive of other locations well into the Sahara or those nearer to Northeastern Africa. Cherni et al.'s (2005) study showed that there were still coastal Maghrebi populations that retained or preserved substantial African-specific uniparental component.

Mystery Solver said...

3) Too Tall Jones writes:

And what about the date discrepancy Keita criticizes in the recent Manchester conference- U6 emergence is held by some to range well into 66kya, but according to Nati Geog's Genographic Project, humans only left Africa 60kya, creating a logical impossibility of "reutrning' Africans predating those who had not even left the continent yet. Is this basically reasonable statement of the date discrepancy issue or is their inaccuracy?

Yeah, age estimation consistency is a hard thing to come by between these DNA journals, not to mention at times, between human paleontological record and estimated DNA TMRCA ages. The next best thing to do is to round off to an age range from where most journal reports fall, and hope to make sense out of it.

You are right in that the 66 kya mark conflicts the often estimated age ranges of OOA migratory event of anatomically modern humans. It points to the quite hypothetical nature of looking that far back in time depth, and human limitations to extrapolating from just some of the pieces of info that form a larger puzzle.

Heck, while geneticists are comfortable in labeling markers as "Eurasian" this or "African" that, there is still way too many uncertainties within the uniparental phylogenetic network. Since the mtDNA network is even more elaborate and seemingly show greater time-depths at the basal positions of the network, there are even more uncertainties about mtDNA phylogeny than the Y-DNA counterpart. I've made note of this elsewhere too.

Have you ever noticed that many clades assigned to "Eurasia" are generally done so on the account of either diversity and/or frequency, as opposed to finding actual basal clades? Anyway, the age discrepancy you mention makes me wonder if it cannot be the expression of the mtDNA regions studied by the respective studies. Maca-Meyer et a. (2003) for instance report noticeably distinct patterns between the mtDNA coding region estimated TMRCA ages and the HVR estimated TMRCA ages. The latter generally report greater time-depth ages than the former, which is not surprising given the former's relatively lower mutation rates. Maca-Meyer et al. (2003) for example, reported an overall age of ca. 66,222 ± 25,269 years for U6, according to the estimated HVR mutation rate extrapolated from those across the sub-clades taken into consideration, while having reported an overall of age of ca. 25,297 to 34,130 years, according to the estimated mutation rate extrapolated from those across the coding regions of the considered markers. The 66,222 kya TMRCA age (from the HVR data) clearly recalls that which you mentioned above, while the coding region counterpart falls well short of that.

So, which range to accept and which to reject? Hard call, but I had to pick, I'll be inclined to go with the control region, due to comparatively lower tendency of divergent haplogroups to sport homoplasic mutations between respective control regions. Homoplasic mutations, whether through transitions or reversions, can throw off the age estimation. Whatever the case may be, as far the discrepancy of the ages may be, be it between different DNA journals or within the same study, one this is relatively more certain: U6's presence in Africa has fairly ancient time-depth and predates its age estimated elsewhere outside the continent. This makes hg U6 an African-specific lineage, regardless of where its immediate parent came from. In fact, U6's immediate parent remains elusive; nobody has figured its whereabouts out. So, as it stands, any claim about it being ultimately reflective of "back migration", which its age could very well render illogical, is matter of conjecture or guess work. One thing that remains constant and leaves little room for doubt, is that it is African-specific!

Mystery Solver said...

4) Too Tall Jones writes:

2) Also what is the basic breakdown of mtDNA in Egypt? The Gurna study by Stevanovich seems to show almost 50% "L" or "M1", while the Siwa study of Coudray 2008 holds that Siwa affinity is with sub-Saharan groups. Is this more or less a reasonable breakdown or is data missing from other studies of Egyptian mtDNA?

The claim that the Gurna sample displays substantial amounts of hg L and hg M1 is consistent with other DNA reports, and also the Y-DNA report of hg E1b1b1a by Cruciani et al. (2007). In the said Crucian et al. study, the largest assignment of paraphyletic E-M78 clades went to southern populations like the Gurna.

Mystery Solver said...

Continued...

From Stevanovitch et al. (2003), we have:

However, the Gurnawi gene pool does not consist of a simple combination of Near Eastern and sub-Saharan gene pools, but also consists of an East African specific component. This situation has already been observed for the Ethiopian gene pool (Passarino et al. 1998). Thus, the report of the second population in this geographic area showing similar distribution of mtDNA haplotypes, including the same high frequency of a specific haplogroup (M1), raises the question of a hypothetical presence of an ancestral East African population. Such a population, as evoked by Passarino et al. (1998) for Ethiopia, could have settled on a wider area from Egypt to Ethiopia (including Sudan), the differences between populations due further influences from neighbors (Arabian peninsula for Ethiopia (Maca-Meyer et al. 2001), sub-Saharan input for Sudan as demonstrated in this study by a high exchange rate between Sudanese and Kenyan populations). A similar hypothesis of the existence of an ancestral population characterized by specific haplogroup could also be evoked in the Maghreb with the U6 haplogroup (Brakez et al. 2001; Rando et al. 1998).

According to Stevanovitch et al.(2003) the presence of hg L and hg M1 reflects the local population stratum in the Nile Valley region prior to possible immigration from overseas. They buttress this with the claim that these markers link the Gurna with other populations further south, and that sub-clades show an unbroken regional link to populations in Sudan and the African Horn. Furthermore, the Gurna populations seems to reflect the "meeting point" of where "back-migrants" genetically exchanged with the autochthonous African group, due to the samples report for markers that have rarer continental distribution than elsewhere out of the continent and those markers that are largely African-specific in distribution and rarer outside the continent. The authors were of the mindset that this original hg L and hg M1 rich populations stretching from sub-Saharan African to Egypt where subsequently influenced by genetic input from geographically proximate populations in and outside of the continent. Sounds reasonable enough, but it should be pointed out, as I have done in the blog post about the Cro-Magnon, that a number the so-called "Eurasian" markers in northeastern Africa and sub-Saharan eastern Africa are actually internally distinct and rare, if not absent, outside of the continent. If such clades were in fact from territory outside of the African mainland, then they must have come very early in their phylogenetic and expansion history, likely very shortly after their emergence.

Mystery Solver said...

Continued...

As far as mtDNA patterns go across entire Egypt, studies on them have been far and between. Major focus areas have been in southern Egypt and the western desert oasis areas, like Siwa. It is reasonable to expect lower preservation rate of African-specific markers in the more northern areas of Egypt than the southern counterparts. This is something recognized by Stevanovitch et al. (2003), as made evident as follows:

The results of this study point a genetic structure of the Gurna population similar to that of the Ethiopian one. This population structure has probably been conserved in some other Egyptian populations even though those which have already been analyzed, such as Mansoura, Assiout and Cairo, **failed** to show the same characteristics. Mansoura, Assiout and Cairo are very big cities with much continuous and current admixtures of individuals from several other regions and countries forming great melting pots.

Consequently, the data from these great conurbations could be somewhat biased. More extensive investigation of the genetic structure of Egyptians from other villages and Ethiopian and Sudanese populations will be required to complete the understanding of the structuring of the current population from the ancestral East African population


Source:

Mitochondrial DNA sequence diversity in a Sedentary population from Egypt

I hope my somewhat long-winded input has helped answer your queries.

Ps - The study was also discussed on the Nile Valley forum a few years back. See: http://thenile.phpbb-host.com/ftopic308.php

Too Tall Jones said...

Hey, your input isn't long winded at all, and yup, it has given me a lot of answers, and info to look over. Thanks.

Too Tall Jones said...

PS: you also referenced Cherni's warning about the patchy nature of the North African mtDNA landscape. How would you see the breakdown of the peopling of North Africa? It seems from the "patchwork" there might be 3 groups:

1--Indigenous Africans in the north (from early on as part of indigenous African movement from East Africa, 70-50 kya?


2--Eurasian migrants to the north from Iberia and elsewhere (Neolithic appearance in North Africa?)


3--Later indigenous Africans from further south of the Sahara (Late Neolithic into historic times?)

I am just wondering what the breakdown would be roughly and the time frames. Assorted "mechtoid" types would be part of Group 1 would they not? And would a blend of the above 3 be the patchwork of today's North African population in various measures and places?

Mystery Solver said...

To Too Tall Jones:

Well, by "patchwork", Cherni et al. (2005) are alluding to the premature, if not misleading, generalizations of the Maghrebi mtDNA gene pool based on random samples focused on a few mere preferred spots or the same general area time and again. They are in effect saying that their study signifies that the previous generalizations about the Maghrebi landscape are based on patchy sampling that focus on more or less the same spots time and again, i.e. not comprehensive sampling of the coastal Northwestern African sub-region. One of the two major coastal northern African samples in Cherni et al.'s research blatantly defies the often made gospel about low "sub-Saharan" influence in Maghrebi mtDNA gene pool! More than half of the Kesra samples were implicated with markers traced directly back to "sub-Saharan" Africa, and this is in contrast to their neighbouring coastal northern population.

Even though the Maghrebi region had been occupied by anatomical modern humans for as long as 150, 000 years and possibly longer [likely involving hg L markers], much of the contemporary Maghrebi Imazighen gene pool is of relatively more recent extraction [neolithic era onwards mostly] according to observers like Arredi et al. (2004), though they do preserve longstanding markers like hg U6 and hg M1 [not the eastern African derivatives] of the western African region in generally low to moderate frequencies. I'm inclined to think that much of the so-called "Eurasian" component as a considerable component of some Maghrebi mtDNA gene pool were attained relatively more recently than the Neolithic era time frame...more likely, during the historic period, during increased contact between the Iberian peninsula and the Maghreb and during the European female slave institution in the region. This is not to say that some of the "Eurasian" mtDNA component had not arrived earlier, but rather, just not in the pronounced quantity suggested by certain recent DNA samples.

Based on published material specifics, I think that U6 and M1 carriers first arrived in the Maghreb some time in the Upper Paleolithic from the lower Saharan or Sahelian confines, and then later a portion of these guys moved eastern and into the Levant via the Sinai corridor, resulting in U6 localizing in eastern Africa for the first time. Later on, another batch of U6 carriers -- i.e. U6a1-- back-migrated to western Africa, along with eastern African downstream sub-clades of hg M1 and certain hg L. This latter migration would have involved what one might call proto-Imazighen speakers.

As I have noted time and again, now because the proto-Imazighen groups were likely nomadic pastoralists by inclination, they may very well have been somewhat male-biased, thereby leading them to attain additional hg L markers and other markers of the regions they came into regular contact with in both central and western Africa. This of course, would eventually extend to the Iberian peninsula as well, as trade routes gradually opened with the spread of "Neolithic" agricultural subsistence in parts of southern Europe and particularly during Maghrebi invasions of that region.

BTW, the word you were probably looking for is "mosaic", as opposed to "patchwork"; I've already gone through Cherni et al.'s interpretation of the later above. Hope this takes care of your inquiries.

medjay said...

Excellent insights as usual. You made note of keita's criticism of Joel Irish's study suggesting that rapid microevolution could not have been responsible for changes in dentition between nile valley populations of the epipalaeolithic and later periods, suggesting instead population displacement and replacement from possibly Europe or Asia.

Are you familar with a 2008 Paul Sereno et al study which to me seems to be suggesting the same as Joel Irish? The study was based on the ivestigation of the remains of two populations whose graves were found in Gobero in the Niger desert. These populations,the Kiffian and Terenian existed 1000 years apart and had cultures associated with the Green Sahara.

This is the conclusion drawn by these authors:"Population replacement rather than gradual phenotypic evolution best explains the distinctive craniofacial morphology and funerary practices of the human occupants during phases 2 and 3 in the early and mid-Holocene, respectively, particularly considering the relatively short intervening occupational hiatus."

They draw this conclusion after making frequent references to similarities between the skeletons they discovered and the Mechtoid and Iberomaurusian type(which you have so adequately described as not really being types)of the Mahgreb. Please tell me your opinion of the conclusions of these studies. Would greatly appreciate it. Thanks in advance.

Too Tall Jones said...

Are you familar with a 2008 Paul Sereno et al study which to me seems to be suggesting the same as Joel Irish? The study was based on the ivestigation of the remains of two populations whose graves were found in Gobero in the Niger desert. These populations,the Kiffian and Terenian existed 1000 years apart and had cultures associated with the Green Sahara.

This is the conclusion drawn by these authors:"Population replacement rather than gradual phenotypic evolution best explains the distinctive craniofacial morphology and funerary practices of the human occupants during phases 2 and 3 in the early and mid-Holocene, respectively, particularly considering the relatively short intervening occupational hiatus."


Irish found affinity with GREATER north Africa and "to a lesser extent", SW Asian and European populations. Greater North Africa includes Mali, Chad, Sudan and Niger, and indeed these regions are considered to be 'North Africa' in several physical geography textbooks. See:

http://img41.imageshack.us/img41/5948/northafricadefinition.jpg

So if indeed there is population replacement, it may not at all be primarily due to outside European, "Middle eastern" or "Mechta-Afalou" sources. Indeed, Mechta-Afalous show variability well within the range of other tropical Africans (as they do in the Sudan) and the material culture at Serenno's site links them with the indigenous Kiffian culture. Thus the pattern may well be INTERNAL demic movement (if any) via INDIGENOUS peoples in GREATER North Africa.

Too often assorted "demic" claims fail to see that the peoples of Africa are not "static" but are themselves dynamic and changing, without the need for outside inspiration to explain why. African herdsmen for example using native breeds have impacted hunter-gatherer populations in several areas, via both displacement or co-existence without needing the mysterious "Hamites" of yore, either for inspiration, or their cattle.