Saturday, January 30, 2010

Following Trails of the Cro-Magnon - II

Here, we will conclude our journey on the trails of the Cro-Magnon from the first part (click); going straight to the point... 

hg U6
All eight Ethiopian U6 samples descend from the major U6a1 founder (fig. 2B), which is spread from the Near East to northwestern Africa at appreciable frequencies (Maca-Meyer et al. 2003). Their absence in Yemen suggests that these U6 lineages have likely penetrated to Ethiopia from the north rather than by the sea route from Arabia. Conversely, both Amhara and Tigrai U2 sequences share an HVS-I motif, 16051-16189-16234-16294, that has not been sampled, to date, in North Africa but that can be found at low frequencies in populations of western Asia and the Caucasus (authors' unpublished data).
Aside from the obvious link to northern Africa, of note here, is the absence of U6 derivatives in Yemeni sample. Although not absent in "western Asia" or the Caucasus, the Ethiopian U2 examples allegedly show fairly low incidences in those areas. 

hg U9, and hg U4
Haplogroup-U4 lineages are spread at moderate frequencies all over Europe, western Siberia, and southwestern Asia and coalesce to their most recent common ancestor within the Middle or Late Upper Palaeolithic period (Richards et al. 2000; Tambets et al. 2003). On the basis of complete sequence data (Finnilä et al. 2001; Herrnstadt et al. 2002), the consensus sequence of U4 in Europe differs from the root haplotype of U by nine substitutions. One Tigrai and one Yemeni U sample shared a transition at np 6386 that defines U9, which was recently detected in South Asia (Quintana-Murci et al. 2004). Therefore, haplogroups U4 and U9 are sister clades within a clade that is defined by one control- and one coding-region mutation.

Haplogroup U9 is a rare clade in mtDNA phylogeny, characterized only recently in a few populations of Pakistan (Quintana-Murci et al. 2004). Its presence in Ethiopia and Yemen, together with some Indian-specific M lineages in the Yemeni sample, points to gene flow along the coast of the Arabian Sea. Haplogroups U9 and U4 share two common mutations at the root of their phylogeny (fig. 2B). It is interesting that, in Pakistan, U9 occurs frequently only among the so-called “negroid Makrani” population. In this particular population, lineages specific to sub-Saharan Africans occur as frequently as 39%, which suggests that U9 lineages in Pakistan may have an African origin (Quintana-Murci et al. 2004). Regardless of which coast of the Arabian Sea may have been the origin of U9, its Ethiopian–southern Arabian–Indus Basin distribution hints that its diversification from U4 may have occurred in regions far away from the current area of the highest diversity and frequency of haplogroup U4—East Europe and western Siberia.
This is one of those rare occasions wherein the generally tagged "Eurasian" markers are shared between Ethiopian groups and  the Yemeni counterparts. U9 presents an interesting case, as it apparently shares a recent common ancestry with U4, which links the Ethiopian samples to far off locations, such as Eastern Europe and western Siberia, presumably the areas suspected of U4's ultimate origin, if the language of the piece above is anything to go by, making the two clades sister clades, and not one serving as the parent of the other—perhaps yet another indication that Ethiopian hg N subclades cannot simply be written off as derivatives of "western Eurasian" clades; importantly, U9 cannot be deemed to be Eastern European or western Siberian origin either. The clade which is ancestral to U4, had to have been on the African continent at some point as well, such that an entire standalone clade [albeit with a sibling] would emerge here that is rare outside. This is not surprising, considering another standalone African clade tied to the hg U root—the U6 clade [already covered briefly above, and elsewhere here].

hg X
Two Ethiopian haplogroup X sequences from this study have been characterized elsewhere as belonging to North and East African–specific subclade X1 (Reidla et al. 2003). A control-region sequence similar to the Tigrai X1 haplotype was found recently in a Gurna sample from Egypt, though it was probably mislabeled as “L3” by the authors, since no coding-region markers specific to either haplogroup X or L3 were determined in that study (Stevanovitch et al. 2004). Both Yemeni X sequences, in contrast, belong to the major western Eurasian subclade X2.
And so, we arrive again at another incidence of rare markers shared between northern African samples and east African ones but not with "Near Eastern" or European samples.

hg M1
Haplogroup M1 lineages constitute 17% of the Ethiopian mtDNA sequences, consistent with their high frequency in the region (Passarino et al. 1998; Quintana-Murci et al. 1999; Richards et al. 2003). Two subclades, which can be distinguished by coding-region RFLPs (Quintana-Murci et al. 1999)—M1a by 12345 RsaI (12346T) and M1b by 15883 AvaII (15884A)—together account for 56% of its variation. M1a is further characterized by a transition at np 16359 in HVS-I and is also present in the single Yemeni M1 sample (fig. 2B). M1a can be found together with M1* lineages in populations from the Near East, the Caucasus, and in Europe at marginally low frequencies (Corte-Real et al. 1996; Macaulay et al. 1999; Richards et al. 2000). The minor group M1b, defined by the motif 15884-16260-16320, is restricted to East Africans, having been observed, so far, only in Ethiopians (Quintana-Murci et al. 1999) and in Egypt (authors' unpublished results). It is interesting that the variable noncoding nucleotide 15884 also carries the derived A allele in one Moroccan M1* complete sequence, yet without the characteristic M1b HVS-I pattern (Maca-Meyer et al. 2001). M1a and M1b sequences are rare or absent in North Africans (Corte-Real et al. 1996; Rando et al. 1998; Brakez et al. 2001; Plaza et al. 2003). Instead, a third clade, M1c, defined by a transition at np 16185, covers most of haplogroup M1 variation in northwestern Africa, the Canary Islands, and the Near East. M1c has not been sampled yet among Ethiopians. It is intriguing that a Moroccan M1c complete sequence (Maca-Meyer et al. 2001) lacks the 813-6671-12950C mutations that define a common branch holding the M1a and M1b clades (fig. 4). It is notable that the other Moroccan M1 sequence with the 15884 mutation also lacks the 6671-12950C signature. In light of these data and because of the lack of other distinctive East African–specific mtDNA haplogroups in northwestern Africa, it is difficult to interpret the northwestern African haplogroup M1 variation as a derivative from the East African mtDNA pool...
Click on the image for greater resolution.

On the other hand,
Yemeni M sequences show matches with some Indian sequences—for example, in M3 (Kivisild et al. 1999, 2003a; Bamshad et al. 2001). Their presence probably reflects recent gene flow, consistent with the historical fact that southern Yemen was under the rule of British India during 1839–1937 and that a substantial population of South Asians can be found in southern Yemen today.
The absence of hg M1 in Yemeni samples stays on-course of that seen in several other markers discussed above, in presenting an overall theme that puts to question the idea that casually "Eurasian"-tagged  markers must have come about in the African horn from proto-Ethiopic Semitic speakers from the Arabian peninsula marching into that area. Some observers have questionably tried to coincide such a scenario with Ethiopic-Sabean contacts [see here, for example] during the height of the Sabean complex. Hg M1 itself has been the subject of much speculation, aspects of which were previously discussed here; however, little attention was given then to the most likely geographical origin of the clade inside the African continent itself. The presence of hg M1c alongside hg M1a in the "Near East" but not in Europe suggests more than one wave of migration scenario.

The passage of  hg M1c probably paralleled that involving some dispersal of hg U6 [likely complimentary with the hg U6a (not U6a1) dispersal from west to east] into the "Near East" ultimately from western Sahara, as the latter is largely absent in Europe as well, with U6 subclades being largely confined to the Iberian peninsula area, right next to coastal northwestern Tamazight speakers. On the other hand, M1a has been implicated in European distribution, the Caucasus and the "Near East", a pattern which is more in line with what one would expect in the often talked-about demic diffusion involving first farmers from the "Near East" into Europe. The question then becomes, when else would hg M1c have dispersed into the so-called Near East?

If Maca-Meyer et al. (2003) are anything to go by, then one would have to assume that this migratory event took place some time before the LGM or its contemporaneous Ogolian desertification. It has to be remembered that U6 constitutes a fairly small portion of contemporary coastal northern African gene pool, going off of DNA studies published in the "West", and its situation in the Sahara, particularly in the western areas, predates the ethnogenesis of Tamazight ("Berber") speakers in the region. However, low frequencies of U6a1 seem to have made their way back to hg U6 clade's homeland, western Sahara. These younger clades joining the older examples thereof, may be serving as telltale signs of movement with proto-Afrisan or proto-Imazighen speakers. Interestingly enough, hg U6 has not been located in Siwa samples, a Tamazight-speaking group on the coastal north-western area of Egypt. This supports the said scenario that hg M1c likely spilled over into the Near East, along with with some doses of hg U6 prior to the coming about of proto-Afrisan speaking ancestors of Tamazight speakers.

However, noticeable frequencies of hg M1 has been reported in those samples. Biparental nuclear DNA seems to hint on relative geographical and social isolation of the Siwa from other more western situated Imazighen groups. So, U6 is not a perfect marker for the spread of Afrisan language, although the same case can be argued for both hg M1 and hg U6 in the case of Yemen, where Semitic language phylum is spoken, yet neither of these markers have been located there to date. This may well be because the population movements in the Arabian peninsula mainly involved groups moving in from the north of the peninsula, the area that got more immediately impacted by Neolithic demic-diffusion of proto-Afrisan speakers from Africa. It must not be forgotten that these Neolithic Africans integrated with preexisting groups in the "Middle East", and so, likely made up a visible portion but one that paled in size when compared to the autochthonous component. So after all the fission and fusions in the northern part of the Arabian peninsula and the Levant, in the midst of all that movement down the Arabian peninsula of the Neolithic farming groups, and given the relative bottlenecks associated with movements, not to leave out effects of genetic drift, the paternal component of the Neolithic or late Paleolithic Africans was better preserved than the maternal markers in the overall gene pool.

In any case, the demographic episodes described here about hg U6 would be consistent with the distribution pattern of hg E-M81 markers, which are prevalent in Tamazight-speaking groups but rare in groups in the "Near East", Caucasus, and "Europe" at large [save for the Iberian peninsula region]. The initial expansions eastward of hg U6 eastward and into the "Near East" would have excluded hg E-M81 and E-M78 carriers. In both the earlier and subsequent demic-diffusions of hgs M1 and U6, it would appear that the M1 clades were generally the predominant of the two, so that in areas where moderate to low incidences of hg M1 made their way, hg U6 clades were likely to either be rare or absent, through subsequent genetic drift and/or masking from latter demographic episodes.

In almost all the areas where hg M1 has been reported, hg U6 seem to occur in comparatively lower frequencies. With all of this said, one might ponder: What hg M1 clades then, could possibly be suggestive of movement of proto-Afrisan or proto-Tamaizight speakers into the Maghreb areas, if not the subclade M1c?

In the hg M1 map provided above, one might notice that the Maghrebian examples fall into two sub-phylogens; one branch leads to M1c, although no coding-region characteristic motive is given here, that separates it from the M1 root—just a HVR-1 position. On the other hand, the other Maghrebian example shares one coding-region motif with the hg M1a and hg M1b subclades, which are prevalent in eastern Africa—the 813 motif. Still, as noted, the both the Maghrebian examples lack the 6671-12950C motifs shared between subclades M1a and M1b. Could the distinctive Maghrebian clades be considered elements of the same demographic episode, or multiple? Hard to tell, except to reiterate that hg M1a and hg M1b are rare to absent in the far western Maghrebian populations, based on thus far published journals in the "West", which at least one research team has admitted, constitute fragmentary and patchy sampling data.

Conventional wisdom would intimate that if hg M1a and hg M1b were around, then does it not make sense that they too should be detected alongside the older clades and/or sibling clades?! One would think that if hgs M1a and M1b were around at more or less the same time as the Maghrebian example they share a single common coding-region motif with from the hg M1 root, then they too should exhibit just about the same chance of getting identified in the involved Maghrebian population as the latter. Well, this need not necessarily be so, since it appears that even the Maghrebian clade in question is rather rare itself in the Maghreb and elsewhere. So, if it were part of low frequency incursions of hg M1a and/or hg M1b, which would eventually be subject to action of genetic drift or masked by multiple subsequent demographic episodes, then one would expect its chances of detection at random, to be just as rare as that of the latter.

Now of course, the presence of hg M1c alongside the rare Maghrebian example described above may be interpreted in some quarters as possibly indicative of a bifurcation event that took place before the emergence of either sub-clades M1a or M1b, and hence, explaining away the rare or absent occurrence of the latter in the Maghrebian population(s) in question, but if proto-Afrisan speakers [perhaps male-biased, as pointed out here before] moved into the Maghreb with fairly modest frequencies of hg M1a and/or hg M1b under the aforementioned scenario—wherein the rare Maghrebian example was part of the incursion—and thereby met up with preexisting hg M1c bearing groups, and wherein U6 were present in observable frequencies, then it is not inconceivable to see the patterns we are now confronting.

Some might be susceptible to forgetting that the demographic episodes involving proto-Tamazight speakers deep into the Maghreb, likely complimentary to the spread of E1b1b carriers (E-M81 and E-M78 markers), occurred relatively late in the early Holocene,  and not necessarily convergent with the spread of Neolithic first farmers bearing E-M78 and other E1b1b clades [like E-M34]; Luis et al. (2004) for example—put the coalescent time frames for E-M81, generally considered a characteristic male Tamazight marker—at ca. 2 ky ago or so.

The initial Neolithic episodes of E-M78 movements, which culminated in the spillover into the "Near East" are distinct from the expansion time frame associated with proto-Tamazight speakers, which depending on sources that one references, generally starts ca. 6 to 8 ky ago, in the eastern areas of the Sahara. This initial coalescent time frame places these groups in the era of the spread of Neolithic farming subsistence groups into Europe from the so-called "Near East", and hence, providing a pretext for some observers to equate it with possible "parallel" impact of Neolithic farming demic-diffusion episodes on the African continent, to that of Europe [See Arredi et al. (2004); Barbujani et al. (1994); Bosch, et al. (1997), Rando et al. (1998)], which some have justified on the account of Hg J distribution in northern Africa, a marker that has no less been determined to have involved vastly chronological distinct demographic events with different incursion levels of the lineage—with much of this gene pool coming from incursions in the historic times.

Never mind, 1) that much of the "Eurasian" tagged mtDNA markers implicated in the Maghreb have been described as variants of European sub-clades, particularly from across the Iberian peninsula, and a sizable portion of which seems to have been attained through the historic period, 2) that farming subsistence in northern Africa as a whole is markedly different from that of the spread into Europe from a temporal standpoint, 3) that the characteristic Tamazight male marker is rare or absent in the "Near East", or 4) that Tamazight language phylum is not spoken outside of the continent. If a portion of "Near Eastern" maternal gene pool did spill over into northern Africa, as a reverberation of growth induced by Neolithic farming subsistence in the "Near East", then the elements carrying these markers met with a different situation on the African continent than that on the other side of the Mediterranean sea, and therefore responded differently according to those conditions.

For instance, it would appear that they abruptly dropped large scale farming subsistence for some reason, whereas the case appears to be otherwise on the other side of the Mediterranean sea. Cattle domestication seems to have taken up the breeding of the local sibling of the "Near Eastern" cattle quite early on, at a time more or less contemporaneous to that of the "Near East" but interestingly not in Europe at the time, and again, seemingly before taking up large scale farming subsistence and incorporation of "Near Eastern" fauna domesticates into northern Africa.

How is any of this relevant to the ongoing matter of the "Cro-Magnon"? It takes us back to that theme of "Caucasians" roaming northern Africa, where all that talk about "Cro-Magnoid" remains having been found in coastal northern Africa, under the banner of Mechtoids fall right in. Maca-Meyer et al. (2003) for example, could not resist such talk, when they wrote:
The expansion of Caucasians in Africa has been correlated with the spread and diversification of Afroasiatic languages.
Yes, it can be said that these specimens generally predate the spread of Neolithic farming subsistence into Europe at any rate, but seeing how "Cro-Magnon" unjustifiably became a synonym for "us Caucasians"—which Brace et al. (2005) termed as nothing more than anthropological folklore, the tacit idea is that "invading" Neolithic "Caucasians" of northern Africa would have been "Cro-Magnon" or "Cro-Magnoid" relatives of the "Cro-Magnon" types or "Caucasians" from the "Near East". Of course, there is no unison viewpoint of how "Caucasians" infiltrated northern Africa; one viewpoint assumes the position that early incursions occurred during the Upper Paleolithic directly from Europe through the Gibraltar Strait, mainly based off of erroneous examination of archaeological lithic-complex in northern Africa dubbed as "Ibero-Maurusian", and the other, well, the just described Neolithic demic-diffusion episodes. Nor should it be assumed that one or the other is accepted while the other rejected, as some ideologues may argue that both conditions are plausible.The phylogenetic placement of "Cro-Magnon" into the hg N mtDNA network is part of this theme; i.e. "Cro-Magnon are us"—the "Europeans" or "Caucasians".

Recalling the Paglicci specimen sequences in the first half of this topic, one clearly sees that there are maternal DNA evolutionary gaps between the Paglicci-25 specimen and that of Paglicci-12 specimen [the latter's sequences according to the study, are suggestive of a more basal phylogenetic position than that of the former within the hg N network], if one is to go by Caramelli et al.'s findings, around which questions still abound. Yet, they are supposed to belong to the same general era (Gravettian). It should be interesting to see what sequencing for Y-DNA in some "Cro-Magnon" tagged specimens will bear, should such endeavor ever be undertaken.

This brings us to the role of Y markers in all this; again citing Kivisild et al. (2004)...
...Several mtDNA haplogroups—such as (preHV)1, U6, and some subbranches of L3 that Ethiopians share with North African populationsdisplay coalescent times in the early Holocene (table 3) a similar period to that estimated for North and East African Y chromosomes in haplogroup E3b1-M78, which is abundant and may have originated in Ethiopia (Cruciani et al. 2004; Luis et al. 2004). It is interesting that, like E3b1-M78, these mtDNA haplogroups are infrequent or absent in our Yemeni sample (table 1). Note that the identified time window is close to the proposed division of the Semitic and Cushitic branches of Afro-Asiatic languages (Militarev 2003) and corresponds broadly to the beginning of deep environmental changes in the deserts of the Sahara and the Arabian Peninsula, when those regions recovered from their widest span and most extreme aridity during the Last Glacial Maximum period.
Given what the authors say about mtDNA like pre-HV markers, attempt at correlation here can only hint on possible entertainment of back-migration involving "Afro-Asiatic" groups from the "Near East" through the Sinai corridor as opposed to the south Arabian peninsula [note here, that invocation of the low incidence of E-M78 in Yemeni samples fit into that theme].

...similar to mtDNA haplogroup (preHV)1, Y-chromosomal haplogroup J1-M267 can be identified as the sole branch that is highly abundant in the Near and Middle East and in northeastern and East Africa (Underhill et al. 2000; Semino et al. 2002, 2004; Luis et al. 2004). Higher STR diversity of this Y-chromosomal clade among Europeans and Ethiopians, as compared with populations from northeastern Africa and the Middle East, suggests that it may have reached Ethiopia (and Europe) early in the Holocene, whereas its frequent spread in North Africa and the Middle East may have been driven by the expansion of Arabs since the 7th century (Semino et al. 2004). As for the E3b-M35 subclades, the problem is to fit a proposed >30,000-year-old split between the two major sister clades—J1-M267 and J2-M172 (Semino et al. 2004)— into this scenario. Somewhat indirectly (inferred from figure 1 of Luis et al. 2004), J1-M267 chromosomes appear to be particularly frequent among southern Arabians (38% in Omanis) and well represented in Egypt (20%). Absence of the corresponding STR variation patterns for the Omani and Egyptian samples does not allow, at present, the inference of which, if either of the two, is likely to be closer to the Ethiopian J1-M267 chromosomes. Nevertheless, a clear asymmetry between E3b1-M78 and J1-M267 chromosomes is seen—the former are rare or absent in southern Arabia, whereas the latter are relatively frequent. Hence, Ethiopians may have been recipients of the southern Arabian J1-M267 chromosomes but have not been efficient donors of the E3b1-M78 chromosomes to southern Arabia, although East Africans may have carried the latter to Egypt and, farther, to Europe via the Levantine corridor. Furthermore, as already mentioned above, there is a profound difference in J1-M267 frequencies between the Semitic-speaking Amharas, who probably arrived relatively recently from Arabia, and the Cushitic-speaking Oromos, among whom the frequency of J1-M267 chromosomes does not exceed 3% (Cruciani et al. 2004). Relevant data for other Ethiopian populations and Yemenis are desired for further exploration of this line of arguments.
What's interesting in the above, in their investigation into whether proto-Semitic speakers arrived with what they essentially tag as "Eurasian" mtDNA markers from the Near East through the Sinai corridor or whether the arrival of Ethio-Semitic speakers was an element of another demographic episode involving the tip of the south Arabian peninsula, is that Kivisild et el. sought to entertain the correlation with a bifurcation event around the E-M35 clade that they think could effectively parallel that concerning the mentioned J clades.

Whatever could they do with that information, one might ask. Although one cannot literally get into the authors' heads, it can allow for extrapolation of the arrival of E-M35 carrying proto-Ethiopic Semitic, in tandem with hg J bearers, as back-migration of Neolithic "Afro-Asiatic" speakers from the "Near East", and thereof, conveniently explain away the distinctive mosaic of unique and conventional "Eurasian" tagged mtDNA markers reported in Ethiopian samples, that just don't seem to square with arrival from the tip of the south Arabian peninsula. This would place the south Arabian source hypothesis on the back burner.

The inability to come up with such a parallel in the E-M35 clade, is what is described here as a "problem". Never mind the fact that E-M35 is a marker of recent African ancestry, but the obvious goal here, was to speak of "returning" variants of this clade. To compensate for this, as an alternative, Kivisild et al. propose that the highly diverse Ethiopian gene pool of Hg J-M267 instead could have entered differently from the other markers investigated here, largely mtDNA markers. Rather, J-M267 is proposed to have arrived from the tip of the south Arabian peninsula recently, coinciding with the arrival of proto-Ethiopic Semitic speakers, as described above not too long ago in this post. Just how recent is "recently" here? Because right before saying that the Semitic-speaking Amharas "arrived relatively recently", the authors note the genetic indications of an early Holocene arrival.

Thus, the demographic events involving the arrival of a host of other markers discussed here were likely different from the arrival from proto-Ethiopic Semitic speakers, whose trail—according to Kivisild et al.'s proposal—is represented by Hg J-M267 as opposed to Hg E-M35, making it expedient to link them back to the southern tip of the Arabian peninsula. To compensate for the stark differences between the Ethiopian mtDNA gene pools and those of the Yemeni counterparts, the authors simply theorize that the south Arabians "efficiently" contributed their male gene pool but not the maternally-transmitted one.

Neither the context or dates of this phenomenon is specified to the reader, of course. Nor are any molecular specifics provided to justify this theory, other than the seeming linguistic-structuring of hg J prevalence amongst Ethiopic Semitic groups and the Cushitic groups, which is why we are simply told this: Relevant data for other Ethiopian populations and Yemenis are desired for further exploration of this line of arguments.

It should be noted however, that while it's true that their hg J-M267 gene pool  is quite diverse, Ethiopians also carry distinctive paraphyletic clades of their own, opening up the question of possible origin of certain sub-clades of this clade amongst Ethiopic groups. This attests to the richness and perhaps antiquity of hg J-M267 in the African horn, one very likely predating contact with Sabean complex, which would have had fairly little, if any, genetic impact on Ethiopic populations outside the centers of immediate Sabean political outposts. It is also questionable, pending the presentation of information forth, that the patterns in Ethiopian examples will be replicated in south Arabian examples. According to Semino et al.'s report, there is microsatellite indication that much of Ethiopian hg J-M267 examples are of Neolithic provenance...
The majority of J-M267 Y chromosomes harbor the single-banded motif YCAIIa22-YCAIIb22 in the Middle East (>70%) and in North Africa (>90%), whereas this association is much less frequent in Ethiopia and only sporadically found in southern Europe. Considering the distribution of this YCAII single-banded pattern—which, besides the usual stepwise mutational mechanism, could be due to a stable mutational event (one locus deletion or a single-nucleotide mutation in the primer sequence)—we suggest that the motif YCAIIa22-YCAIIb22 potentially characterizes a monophyletic clade of J-M267...According to this interpretation, the first migration, probably in Neolithic times, brought J-M267 to Ethiopia and Europe, whereas a second, more-recent migration diffused the clade harboring the microsatellite motif YCAIIa22-YCAIIb22 in the southern part of the Middle East and in North Africa. In this regard, it is worth noting that the median expansion time of the J-M267-YCAIIa22-YCAIIb22 clade was estimated to be 8.7–4.3 ky, by use of the TD approach (see fig. 4 legend), and that this clade includes the modal haplotype DYS19-14/DYS388-17/DYS390-23/DYS391-11/DYS392-11 of the Galilee (Nebel et al. 2000) and of Moroccan Arabs (Bosch et al. 2001).
If true, this would mean that any "Afro-Asiatic" hg J-M267 from southern Arabia would have had to have been acquainted with the farming subsistence from the Levantine areas, and as such, certain Neolithic social terms associated with such economy would have been available. As noted here before, nothing comes to mind that suggests basic "Near Eastern" or "south Arabian" Neolithic-derived terms in Ethio-Semitic.

Kivisild et al. are essentially treating hg J1-M267 as the effective marker for proto-Semitic speakers in Ethiopic populations, as opposed to E-M78 or E-M35 clades, which is odd, because the primary agents of spreading proto-Semitic or proto-Afrisan languages into the "Near East" and the Arabian peninsula in the first place would have largely been E-M35 carriers, who originate from an area where preponderance of evidence—including both genetic particulars and language diversity—places the origin of proto-Afrisan language phylum. This therefore puts hg J carrying groups in the "Near East" and elsewhere on the receiving end of "Afro-Asiatic" language acculturation, not the primary agents of it.

The structuring of hg J clades along linguistic lines within Ethiopian samples simply says that these groups likely merged together from distinctive demographic episodes; one involving the group predominantly comprising of proto-Ethiopic Semitic speakers—likely carrying both hg E-M35 clades and hg J clades—and the other,  predominantly Cushitic speaking groupsthat's just about it; it tells us very little about the specific direction from which the aforementioned linguistically-structured markers respectively arrived—be it from the north or from the southern Arabia, short of comprehensive comparative analysis at the molecular levels between the Ethiopic groups and geographically proximate, exotic, non-Ethiopic groups.

Kivisild et al. were compelled to make J1-M267 into THE telltale marker for the spread of proto-Semitic phylum into the African horn, because they recognized the low to absent incidences of E-M78 in south Arabian samples, which no less were not based on actual sampling of Yemeni population at the time of their observations, but at the same time they had to contend with linguistic reconstructions that place Ethio-Semitic languages into the southern branch of the Semitic phylum.

For those who are bent on explaining away autochthonous coming about of Semitic languages on African soil, this element entices the cooking up of theories around an origin in the southern tip of the Arabian peninsula, no matter how tenuous. One cannot also help but arrive at the conclusion that the presence of E-M34 clades in southern Arabia must have been elusive to the authors in question, and that it may well be serving as a marker of Afrisan diffusion into that region.

In Cruciani et al.'s 2004 journal, which the authors rely on, not only had E-M34 markers been reported in the sole southern Arabian sample (Omani), but so had the E-M78 counterparts, and they occur in identical incidences. That said, E3b1c1-M34 chromosomes are visibly prevalent in Ethiopian groups, as they are across the whole stretch of northern Africa.

From the earlier mentioned Semino et al. (2004) study, as it concerns the compatibility of Ethiopian J1-M267 clades with the idea of their introduction by southern Arabians, particularly their nearest neighbors—the Yemeni, it was acknowledged that:
The lower internal variance of J-M267 in the Middle East and North Africa, relative to Europe and Ethiopia, is suggestive of two different migrations.  - Semino et al. (2004)
This revelation to the authors' above is consistent with those reported elsewhere, and may well prove instructive in the quest to determine the duplicity of Ethiopian hg J clades with those in southern Arabia, particularly those of Yemen:
At another extreme, the haplogroup distribution of Yemen shows very limited variation, particularly when compared to neighboring populations, Oman and UAE (3 versus 11 haplogroups each), whereas Qatar is intermediate with a total of seven haplogroups, four of which display frequencies of less than 3.0%. Although Qatar does not approximate the lack of diversity seen in Yemen, the two populations display affinities that are apparent in the MDS plot, in which populations of the Levant are interspersed among the South Arabian populations, with Qatar and Yemen segregating apart from both UAE and Oman. - Cadenas et al. (2007)
The authors figure that one of the underlying causes for this reduction in diversity of Yemeni Y-DNA gene pool, in addition to subsequent expansions masking earlier ones, could be a matter of a "high degree of consanguinity" within the population. Having said that, elsewhere, they wrote:
Median BATWING expansion times based on Y-STR data for the Omani (2.3 ky; 95% CI: 0.6–29.2) J1-M267 chromosomes4 indicate a more recent arrival to the South Arabian populations as compared to the older expansion times obtained for the Egyptian (6.4 ky; 95% CI: 0.6–278.5)4 and Turkish (15.4 ky; 95% CI: 0.4–604.8)12 representatives of this haplogroup. Conversely, in the present study, Y-STR age estimates based on the method described by Zhivotovsky et al46 generated much older values for the J1-M267 haplogroup in Yemen, Qatar and UAE (9.7 +/- 2.4, 7.4 +/- 2.3 and 6.4 +/- 1.4 ky, respectively) than seen in the Omani,4 consistent with an earlier arrival to the region during the Neolithic. The data suggest expansion from the north during the Neolithic (or perhaps more recently), which is also reflected in the lower STR variances in southern Arabia (0.14 for Qatar, 0.15 for UAE, 0.20 for Yemen and 0.27 for Oman4 versus 0.31 in Egypt4 and 0.51 in Turkey12). Subsequently, a series of recent demographic events may account for the high haplogroup frequency of J1-M267 in the populations from the present study.  - Cadenas et al. (2007)
Like Semino et al. (2004) and Luis et al. (2004) before them, these authors too note the higher intra-haplogroup variance in J1-M267 chromosomes in areas to the north of the southern Arabian territories mentioned here both in the "Middle East" and Northeastern Africa than those in populations of said southern Arabian peninsula areas. In light of this, it is important to reiterate, just as the said authors themselves did by citing Semino et al. (2004), that the Ethiopian hg J1 clade gene pool was even more varied than those from the "Middle East" and coastal Northern Africa.

Furthermore, just as the aforementioned authors in the 2004 publications note the older expansion ages for populations to the north of the more southward-oriented populations in the Arabian peninsula, the authors here too arrive at the same conclusion, noting that the expansions appear to have began from the Neolithic times onwards from the north to south along the Arabian peninsula. Yet again, Ethiopian hg J clades in turn show older expansion ages than sections of Northern African and "Middle Eastern" gene pool, which have been affected by more recent demographic events, as have the southern Arabian groups mentioned here.

The estimated upper-end expansion time frame of Yemen's hg J1 gene pool in particular is one that is not inconsistent with that generally associated with the spread of Neolithic farming subsistence, but the more internally more varied hg J1 clades of Ethiopia than those in Yemen (not to mention the distinctive aforementioned paraphyletic clades of Ethiopia), and the rest of the south Arabian groups described here, is inconsistent with an idea of introduction from Yemen, or any other southern Arabian territory for that matter.

This is significant, considering that hg J has a considerable presence in Yemeni Y-DNA gene pool; 72.6% according to Cadenas et al. (2007). The picture is no less different, when it comes to E1b1b1c (E-M123 or its subclade "E-M34")  chromosomes; while Cadenas et al. (2007) cited Cruciani et al.'s (2004) reckoning about the plausibility of Ethiopian E3b1c1-M34 bearing chromosomes arriving from the "Near East", they did not go quite as far as suggesting a "Near Eastern" origin for the clade in any context:
On the other hand, Cruciani et al57 have postulated that the E3b1c-M123 clade may have originated in the Near East, as its presence in East Africa is restricted to Ethiopia (11.2%). The median expansion time for M123 in Egypt is 10.8 ky,4 comparable to the estimated age of M123 STR variation obtained through the method described by Zhivotovsky et al46 for UAE (11.1 +/- 3.9 ky) and Yemen (10.6 +/- 4.1 ky), although allelic differences between these two populations indicate that they do not share a common ancestry. Recent archaeological finds supports a trading relationship between Mesopotamia and the Arabian Gulf region dating back to the Al Ubaid Period (~7000 yBP) as evidenced by the excavation of Ubaid pottery from Mesopotamia in UAE.8–10 Ancient maritime trade routes linking Mesopotamia to the Indus Valley included Dilmun (the island of Bahrain) and Magan (in the southeastern tip of the Arabian Peninsula). It is possible that the close ties between Mesopotamia with both the Nile River Valley and the ancient Persian Gulf region during the Neolithic helped disseminate these haplogroups- Cadenas et al. (2007)
In fact, the authors' language suggests acknowledgment of E3b1c-M123 as more of a marker of African ancestry than one of "back-migration":
The E3b1-M35 sub-haplogroups, M123 and M78, are believed to have spread from East Africa to North Africa and later expanded eastward through the Levantine corridor and westward to northwestern Africa. Although E3b1a-M78 data suggest that this dispersal occurred in both directions,4,34,47 E3b1c-M123 disseminated primarily to the east.4 The distribution of the E3b1-M35 derivatives in Yemen, Qatar and UAE agrees with their arrival by expansion via the Levantine corridor rather than through the Horn of Africa. This route is similar to general patterns of Levantine mtDNA gene flows during the Upper Paleolithic55 to the Neolithic.5,55 This is immediately apparent by the M35 profile of several East African populations. - Cadenas et al. (2007)
Having noted Cruciani et al.'s (2004) postulation, the authors merely note that the trade network between said regions may have facilitated the spread of E3b1c-M123, which was followed by its expansion downward in the Arabian peninsula, wherein it appears to have undergone multiple founder effect—and likely genetic drift thereafter—events, resulting in the patterns noticed in the Arabian peninsula, with different populations having different subsets of E3b1c1-M34 chromosomes, which of course, brings us right back to Cruciani et al.'s (2004) claim of relatively lower internal variation in the Ethiopian E3b1c1-M34 gene pool than those from the "Near East".

Cruciani et al. (2004) provided us with a map of E3b1c-M123 among other E1b1b1 markers, displaying the Y STR network, wherein they tell us that the Ethiopian examples are more closely related than the "Near Eastern" examples, and hence, lesser diversity thereof. As noted here before, an instant look at the map itself doesn't appear to invoke a sense of that much of a difference between the internal diversity of Ethiopian chromosomes and those of "Near Eastern" examples as far as the number of distinctive inter-connecting "branches" that respective haplotypes fall into is concerned, save to say that where said haplotypes are branched-out immediately from one another and having come from populations within the same region or general geography, the Ethiopian examples do appear to display more shorter-length branches in between them than those from the "Near East".

The comparison based on the latter phenomenon though, doesn't come from a level playing field; the Ethiopian haplotypes are expected to show relatively shorter branches with respect to one another, because they are highly geographically-proximate populations of the same nation state, whereas those from the "Near East" were pooled from distinct geographical territories spanning the Asian Minor, the Levant all the way to the southern tip of Arabia.

As we've just seen from above, the "Near East" expansions of E3b1c1-M34, likely first in the northward-oriented territories therein, and then from there towards the south, was marked by multiple "founder effect" situations accompanied by genetic drift—positive or negative, resulting in different subsets of E3b1c-M123 developing internally within respective distinct populations of the region. A fairer assessment would be pooling *all* African examples together, and comparing them with the pooled "Near Eastern" examples. Cadenas et al.'s (2007) posting of internal-diversity of E3b1c1-M34 clades per region is consistent with previous data.

Furthermore, the studies posted here all, and more, keep citing that singular Underhill et al.'s (2004) one study wherein E-M34 was not detected in a Sudanese sample, around which Cruciani et al. (2004) raise their "Near Eastern" origin plausibility, for Ethiopian chromosomes. In that same study, interestingly, no hg J clades were observed in the Sudanese sample either; How is that for a reality check? Yet, other studies have noted hg J markers in Sudanese samples. Semino et al. (2004) for their part, refrained from inferring the origin of Ethiopian E3b1c1-M34 clades, only noting that:
The network of E3b1a-M78 and that of E3b1c-M123 are in agreement with the hypothesis of their ancient presence in the Near East and their subsequent expansion into the southern Balkans. The divergence time (TD) (Zhivotovsky 2001) between the Near East and European lineages has been estimated to a range of 7–14 thousand years (ky) ago. Cinniog˘lu et al. (2004) found a high degree of variance of E3b1c-M123 in Turkey, which has been interpreted as being due to multiple founders rather than a single early dispersal event that has remained geographically circumscribed- Semino et al. (2004)
In Turkey alone, we are confronted with a scenario of multiple founder situations; it has implications on the point made herein and that by Cadenas et al. (2007), about this phenomenon having an impact on the pattern of "internal" variation from across a fairly wide region spanning the Asian minor to the southern tip of the Arabian peninsula, when populations therein are pooled together and pitted against that of the more geographically constricted territory of Ethiopia. The high degree of internal variation in Turkey has been attributed to "multiple founders" from different demographic episodes, but Yemeni and other south Arabian populations, as we shall see below [and also revisit info above], display fairly low internal variation for their E-M34 markers, or conversely, high degree of homogeneity...

From Cadenas et al.'s (2007) posting:
As the MDS plot displayed a close affiliation between South Pakistan and North Iran and the former segregated away from the Gulf of Oman populations, the x^2-test was repeated excluding South Pakistan. Although statistically significant differences are still apparent for haplogroup E (x^2 = 10.170, d.f. = 2, P = 0.0062) and R (x^2 = 10.560, d.f. = 2, P = 0.0051), J (x^2 = 2.577, d.f. = 2, P = 0.2757) exhibits an even distribution among Oman, UAE and South Iran. However, a greater homogeneity is observed among the South Arabian populations of Oman, UAE and Qatar for haplogroups E (x^2 = 2.249, d.f. = 2, P = 0.3248), J (x^2 = 4 831, d.f. = 2, P = 0.0893) and R (x^2 = 0.308, d.f. = 2, P = 0.8573). The significant differences in frequency of haplogroups result in detectable clines moving from the South Arabian populations to South Iran and then South Pakistan (E: 18.8, 6.8 and 3.3%; J: 50.4, 35.0 and 25.3%; and R: 11.2, 25.6 and 46.2% for South Arabia, South Iran14 and South Pakistan,30 respectively).  - Cadenas et a.l. (2007)
The above show gradients, wherein hg E is greatest in southern Arabia and decreases as one proceeds northward to southern Iran, and then eastward to south Pakistan, and the same applies to haplogroup J, while the reverse trend is seen in hg R, with the lowest frequencies in southern Arabia. The piece above notes a greater loss of diversity in all three haplogroups involved when it comes to southern Arabia, compared to the other mentioned regions. Yemeni gene pool for these are yet even more limited in their diversity than the aforementioned south Arabian populations of Oman, UAE and Qatar. Recalling the piece cited earlier:
At another extreme, the haplogroup distribution of Yemen shows very limited variation, particularly when compared to neighboring populations, Oman and UAE (3 versus 11 haplogroups each), whereas Qatar is intermediate with a total of seven haplogroups, four of which display frequencies of less than 3.0%. Although Qatar does not approximate the lack of diversity seen in Yemen, the two populations display affinities that are apparent in the MDS plot, in which populations of the Levant are interspersed among the South Arabian populations, with Qatar and Yemen segregating apart from both UAE and Oman. - Cadenas et al. (2007)
Luis et al. (2004) posted an internal variance of  .41 for the Egyptian sample vs. the just .05 internal variance for the Omani sample, as it pertains to the E3b1c-M123 clade. Likewise, the internal variation of Egyptian J clades—J-12f2(xJ2-M172) and J*-12f2(xJ2-M172)—was .45 and .31 respectively, while those reported for the Omani sample were .40 and .27 respectively. There is apparently greater disparity between the reported values for the two samples in the case of the E-M123 marker than the J clades, but the common element here is the relative greater internal variation in the Egyptian sample vs. the Omani. On the other hand, Cadenas et al. (2007) report the following internal variance values for the following groups respectively: For UAE the value was .25 [E3b1c-M123] and .15 [ J1-M267], while for Yemeni, the values were .14 [E3b1c-M123] and .20 [J1-M267]. Qatar did not report for any E3b1c clades, but did have a value of .14 for J1-M267. The level of diversity demonstrated above in eastern African examples of E3b1c-M123 and J1-M267 markers, including those from Ethiopia, is inconsistent with a south Arabian origin.

The plausible scenario for introduction of hg J1 clades in Ethiopian populations is more likely one wherein the J1 clades arrived early in the continent, whether due to in situ origin or back-migration, and was picked up by the ancestors of contemporary Semitic speaking groups of Ethiopia somewhere in the Sahara, noticeably more northward than their current habitat. However, even if one were to entertain a back-migration scenario as the causal factor for all African J1 clades for arguments sake, it appears to have arrived when the clades were in their very early stages of diversification, hence the abundance of paraphyletic clades, as discussed elsewhere here [link was provided above].

If the spread of the Neolithic farming subsistence played any role in all of this, then one would have to contend that it likely did not accompany some massive movement of people from the so-called "Near East", but rather, small scale migrations likely induced by increasing social organizations in both the so-called "Near East" and the Sahara, paving way to the opening of early and perhaps modest trade routes. This may have primarily involved fauna and possibly flora in the Neolithic context, between populations in each area with a view to liven up their preexisting stock with more choices or variety [with 'exotic' goods]. As such, would-be migrants who decided to settle in a new homeland, simply integrated into preexisting Saharan communities, and thereby not shifting the traditions of host communities in any considerable way.

We've already gone through the lack of immediacy between the so-called "Near Eastern" Neolithic farming "revolution" of economy therein, which is significant, considering that "Near Easterners" are right next door to the northeastern corner of Africa—one would expect entry into the Nile Valley through the Sinai corridor to have been more immediately accessible than many of the areas in mainland Europe, and hence, serve as one of the earliest entry points of demic-diffusion accompanying the spread of a tradition largely of a farming subsistence economy; several researchers claim that archaeological indicators suggest that large farming in northeastern Africa came in more or less about the same time as its spread into some areas in northern Europe, between ca. 8ky to 6ky ago or so, which makes it either on par and/or even later than certain southern areas of Europe. Yet, conversely, cattle domestication is said to have likely arrived before or about the same time as that in the so-called "Near East".

These developments don't square with massive intrusion of migrants into an area, thereby considerably shifting traditions in the destination point. It is against this backdrop that no considerable language shifts would have taken place either, which makes more sense in the Ethiopian context, considering the lack of tracing of "Near Eastern Neolithic-derived" terms in Ethio-Semitic languages. Now of course, the alternative to all this, is that hg J1 could have originated in the Sahara near the northeastern end of the African continent, and it certainly cannot be ruled out in the final analysis—just as the aforementioned matter of great internal diversity and paraphyletic clades demonstrate, but this is a matter that understandably doesn't sit well with many "westerners", just as the fact that E3b1a-M78 could be considered African ancestry [which if any, is usually begrudgingly accepted as African, preferably "northeast as opposed to sub-Saharan African"] and seeing as how both it and the J clade are widely acknowledged to be important markers of the diffusion of the so-called Neolithic farming subsistence into Europe.

Short synopsis on genetic data: It is quite plausible that the ancestors of Ethiopic Semitic speakers where situated in a more northern geographical clime than their current territory. Given mtDNA data presented here and known Y-DNA patterns, in aspects of which there seems to be the recurring element of sharing between Ethiopian groups with northern African groups more immediately than non-African groups, the plausible initial territory of their lingual-ethnogenesis must have been in the Sahara, particularly the eastern areas.

Some of the so-called "Eurasian" markers may have either been clustered in the Saharan region prior to the Ologian period or else at the retreating periods of the intense aridity. One will notice the sporadic appearances of clades like hg N in "sub-Saharan" western Africa, at considerable distances from the areas where the clade is most diverse. This is also seen in hg M1 distribution; the clade shows erratic distributions across "sub-Saharan" west Africa, with even rare clades sporting basal phylogenetic profiles found as far west as Senegal—again, a location that has a good degree of distance from the areas where hg M1 are generally more diverse and frequent.

The hg M1 clade penetrates into "sub-Saharan" Africa to as far as Tanzania, where in a rare situation, it resides alongside other non-M1 hg M clades. It is therefore conceivable that while hg M1 may have ultimately emerged somewhere in "sub-Saharan" Africa, its main diversification likely took place in the Sahara before the Ogolian aridity hit the area—hence, the spread of divergent hg M1 clades east and west along the stretch of the Sahara, Sahel and regions immediately beyond. Since large swaths of central Sahara—amongst other areas—remain understudied, much information on the nature of bifurcation events revolving around this clade [and likely others] will remain elusive. Instead, readers will continue to have to put up with weak theories around African clades, generally lazily written off as "back-migration" in "Western" academia, esp. if the puzzling distributions have not been sorted out.

The tone of sections of geneticist teams seem to be one of discomfort around situations that seem rather too complex to be given simple explanation, which more often than not, usually is the case with distribution patterns of molecular markers in populations worldwide, or in cases where personal [subjective] conflict of interest creeps in, and so, look for the simplest explanations to placate these concerns. This phenomenon has not been lost on some observers within academia; Keita for example, notices that some those markers casually tagged as "Eurasian", may in fact leave misleading impressions of their trail and hence, ultimate origins, if say—they are products of chronologically-complex multiple back and forth demic-diffusion episodes between Africa and nearby 'exotic' locations.

The lack of structuring of the so-called "Eurasian" mtDNA markers along linguistic lines in Ethiopian groups, in contrast to the likes of hg J1-M267, coupled with noticeably distinct patterns in the African Horn and southern Arabia, could suggest the merging of groups from chronologically different demographic episodes before any contact with the southern tip of the Arabian peninsula; groups who otherwise probably used to reside in the same general area before a major bifurcation event. Here is how it could have gone down:

The groups involved were likely clustered along the same geographical confines, which likely was either the gradually northward-retreating early Holocene-era Sahel zone, or clustered along the filling-up river systems like that of the Nile River system passing through the Sahara. With the resumption of aridity in the mid-early Holocene era [~ 5 ky ago], some groups stayed around or moved up along persisting river systems, like the lower areas of Nile River system.

Others simply retreated southward to more hospital environment. In the case of our Ethiopic examples, it seems plausible that one group undertook the former scenario while the other group retreated southward, so that each said groups would have come into contact with and possibly genetic exchanges with different geographically proximate groups, respectively. In the northern territory, one group would have come into contact with populations bearing markers like hg J-M267, E-M34 groups and other hg E clades. Likewise, the other group would have come into contact with extant external groups with another set of genetic profiles, likely distinct from those seen in the aforementioned northern territory, like say—lesser incidences of the "exotic" clades of hg J and/or the more northerly-situated subclades of the E-M35 clade like hg E-M34.

It is of interest, that pretty much all the Afrisan-speaking groups have reported E-V6 incidence [which Kivisild et al. mention in a passing], a clade which is virtually restricted to the African horn, but the Semitic speaking group of Amhara reporting substantially greater incidences than the Cushitic group of Oromo. The only Afrisan group to outdo the Semitic speaking group, were the Omotic-speaking Wolayta [Cruciani et al. 2004]. On the other hand, the only non-Afrisan speaking group outside of the main "horn of Africa" groups to report for E-V6 incidence at comparable frequencies to those of several of the "horn of Africa" samples, was a Nilo-Saharan sample from Kenya.

These patterns are consistent with a scenario wherein the base population of the Semitic speaking groups was one that had already undergone bifurcation within a common ancestral source prior to any contact with Semitic speakers from outside of the continent. This bifurcation may have coincided with language differentiation, culminating in a group with a language substratum that had qualities of Semitic languages [which are after all, offshoots of proto-Afrisan].

The idea here, is that this language substratum probably attained similarities with Sabean language as contact between the African horn region and southern Arabia intensified, likely stemming from situations like the making of a lingua franca out of one of the languages on either sides of the Red Sea; as an example, one sees the use of Sabean language alongside local Ethiopian dialects, at the height of Sabean contact in the region. The aftereffect of such turn of events would leave an impression that Ethio-Semitic is part of southern branch of Semitic language phylum.

No doubt, the rambling on above around population dynamics in Eastern Africa and the Sahara is one that could well be favorably received by those who entertain an African outlet for the Cro-Magnon, as the DNA markers involved include those to which "Cro-Magnon" had been linked.

As for the detailed insight into population movements into the African Horn, one might recall that one of the underlying motives of placing the "Cro-Magnon" at the center of attention both within academia and outside of it, is its "reputation" as the "original Caucasian" and therefore, representative of the "European" or "Caucasian" race, and a lot has correspondingly been spoken of about this paleontological "entity", with regards to traits like "narrow nasal aperture", "orthognathism", etc. to justify such claims, since soft tissue is a none entity on skeletal remains, and so, cannot be applied to speak of a "White race"; the supposed prevalence of similar traits in main centers of attention of the African continent within "Western" academia—as noted earlier, generally eastern Africa and coastal northern Africa—have infamously been explained off within reactionary elements of "Western" folk, again both within and outside academia, as "imported" diversity brought about by wandering "Caucasians". This takes us back to such constructs like for example, Hamitic hypotheses.

The associated matter of the origin of "Afro-Asiatic" language phylum [takes us back to a former naming, like Hamito-Semitic] has been revised over the years to finally acknowledge its African origins, but as we have extensively seen above, there is persistence in attributing African Semitic sub-phylum as an "import" [see the Kivisild et al. example just presented above]. The matter of nasal aperture will be revisited shortly, but first, getting back to an earlier piece, from Bandelt, we have...
The authors further asserted that the mtDNA of both specimens belong to typical Near Eastern haplogroups. In particular, the mtDNA of specimen Paglicci-12, with claimed mutations at sites 73, 10873, and 16223 but none in the stretch 10397–10400 relative to rCRS, was regarded as a member of haplogroup N. They have, however, confused the roles of C and T at 10873 in the mtDNA phylogeny – in fact, C at both sites 10400 and 10873, as observed in Paglicci-12, indicates that this mtDNA haplotype should rather not belong to either of the Eurasian/Oceanian haplogroups M and N, which completely cover the non-African mtDNA pool.
He goes onto say...
Therefore, we would be led to sort this mtDNA lineage into an (unknown) African subhaplogroup of the superhaplogroup L3; but this does not sit easily with the claimed nucleotide A at 10398. The most plausible explanation then is that we are seeing here a mosaic origin of the compound mtDNA haplotype for Paglicci-12. If these problems had been realized in time by the authors themselves, then further coding-region markers could have been analysed for a more thorough characterization of the targeted mtDNA.
According to the above, as the sampling resolution of the Paglicci specimen stands, the phylogenetic placement into the African network of L3 cannot be discounted. With regards to the nucleotide position 10398A, this was put forth elsewhere...
In keeping with the former hypothesis, van der Walt and colleagues[9] report a significant difference in the frequency of 10398G>A in PD. Although this polymorphism is found in both J and K haplogroups, suggesting that this polymorphism defines these two haplogroups,[9] 10398G>A also has been described on other distantly related haplogroup backgrounds, including C, D, E, I, L, and M.[19] This indicates that the polymorphism has arisen at least twice in human evolution (homoplasy),[17] or there have been a number of reversion mutations. In either case, it would be unwise to conclude that 10398G>A defines J and K. In fact, 10398G>A was not detected in any of 46 control haplogroup T sequences,[19] despite the generally held view that J and T are more closely related than J and K.[17][19]  - A. Pyle et al. Mitochondrial DNA haplogroup cluster UKJT reduces the risk of PD, 2005.
With that said, cranio-metrically speaking, there has been some fuss around the nasal aperture; emphasis has been placed on the idea that "Cro-Magnon" type has a narrow nasal aperture, which presumably makes narrow nasal aperture appear in European paleontological records before it does in the African record. This emphasis suggests the entertainment of an underlying notion, that either 1) the Cro-Magnon could not have arrived from Africa, and/or 2) Europeans or the "White race" was responsible for spreading "narrow nasal aperture" around the world, supposedly without which it would not have become part of African physical diversity. Much reference has been to the "narrow" nasal opening of Cro-Magnon I specimen, the first specimen of the series uncovered, but here is another cranium tagged as "Cro-Magnon", missing the mandibule; observe the nasal aperture...

Click on the image for greater resolution

Unlike the "Old man"/Cro-Magnon I, the specimen above, tagged as "BC-093", was uncovered in southwestern Germany [in the Rhine River deposits] near Mainz. And now, a look at this reconstruction...

Click on the image for greater resolution

Is the above individual anything like northern west Eurasians? Yet, this is the involved analysts' idea of what the Early Modern Europeans would have looked like; whatever gave them that idea? Take note of its nasal breadth; is it necessarily what one would describe as "narrow"? Then there is also the Grimaldi remains, which has eventually been dubbed as "Cro-Magnon" as well. When either the nasal breadth or index across these individual so-called specimens are referenced, it becomes noticeable there are obviously no unison nasal indices. The Grimaldi remains have for instance been described in some quarters to have either relatively "broad" nasal aperture, or at least "moderately" broad. The same observation has been made across so-called Mechtoid specimens (Taforalt and Afalou), Cro-Magnon's supposed close anthropological relatives in northern Africa, where varying breadths of nasal apertures have been reported [See for example, Groves1999].

To demonstrate this point, take Robert Franciscus' [who corresponded with the aforementioned Erik Trinkaus] study (1999); it points out that the mean for the Early Modern European samples, which generally includes the so-called Cro-Magnon specimens—concerning nasal breadth—was around the same mean as the early Holocene African samples (mean: 26 mm), and close to the Mesolithic North African samples (mean: 27.4 mm), which include those Mechtoids talked about here, and a recent Bantu sample (mean: 27.1 mm). This is interesting, considering certain stereotypes of "sub-Saharan" Africans and misconceptions of what "Bantu" is, not to mention that north African "Mechtoids" have been likened to the Cro-Magnon of Europe and in some instances, even described as "Caucasoid". If these findings are anything to go by, then one would have to concede that the "Bantu" sample nasal aperture are generally narrow as well. Naturally, mean values hide variability, but the issue here is general trend.

Courtesy of Robert G. Franciscus (1999). Click on the image for greater resolution.

Notice that these days the term European Early Modern Humans (EEMH), as demonstrated above, is increasingly used over the "Cro-Magnon" moniker. This change was inevitable, since the rather ambiguous concept of "Cro-Magnon"—as though it constituted some sort of type—is no longer tenable. There are just too many holes in the rationale of the concept. Of course, when it comes to providing evidence, genetic or bio-anthropology, about how "narrow" nasal aperture or say, orthognathism, are unnatural variations of Africa, the most diverse continent on the planet, which have been demonstrated both genealogically and physically, such as cranial variation-by-distance simulations, none is forthcoming. 

Post-cranial examinations show that some of the most focused on [with "Western" academia] African groups, dubiously associated with "Caucasoids", notably differ from Europeans in body proportion indices. Hiernaux had come up with a bizarre term for some of these groups; the so-called "elongated Africans". Speaking of which, it is notable that early modern European human specimens have turned up limb-proportion and trunk-limb proportion indices closer to those of recent Africans than recent Europeans, who are generally determined to sport short limp proportions, as a response to the cold climate of the temperate environment of Europe. 

These early European modern human specimens included Cro-Magnon samples. Some have posed the question about how early modern humans of Europe from paleontological record managed to retain body proportion indices similar to those of tropical Africans for over several millennia [Frayer et al. (2003), per T.W. Holliday (1999)], given Europe's cold climate environment. As covered here before, it appears that while Paleolithic Europeans produce mean values similar to the tropical African means, which Holliday et al. (2009) describes as "African-like body proportions", other aspects of their physique suggests some change took place, which according to Holliday (1999), could well be reflected in the section [particularly the specimens closer to the turn of the Pleistocene (later Paleolithic specimens) than the earlier Upper Paleolithic examples] of these samples showing "foreshortened" limbs. 

Take note that having "short limbs" does not equal "limb proportionality", although in certain cases, a correlation can be made between the two. Here are some reports from Holliday, on empirical examinations done on samples, ranging from pre-Gravettian and Gravettian samples to several recent human populations:

Click on images in the links to get greater resolution.

Body Proportions—Trenton W. Holliday - 2

Body Proportions—Trenton W. Holliday - 3

Body Proportions—Trenton W. Holliday - 4

Body Proportions—Trenton W. Holliday - 5

Body Proportions—Trenton W. Holliday - 6

Body Proportions—Trenton W. Holliday - 7

Body Proportions—Trenton W. Holliday - 8

Body Proportions—Trenton W. Holliday - 9

Body Proportions—Trenton W. Holliday - 10

Here's a caveat: Earlier the present author wrote...

If Europeans' earliest ancestors came from a sub-tropical refuge center of a generally cool geographical clime of say, central Asia, then one would expect less inclination towards the display of tropical body proportions, having undergone some level of adaptation or another to the sub-tropical environment.

Indeed, there are holdouts out there who reckon that ancestors of Europe must have arrived through central Asia. Richards et al.'s (2000) mtDNA reports and known European Y-DNA patterns are inconsistent with this observation, which show noticeably distinct patterns from those of central Asia. Furthermore, given central Asia's temperate [generally cool, or at most, mild temperature zones] geographical clime, one would think that the ancestors of "Cro-Magnons" or EEMHs would have undergone some adaptation to the temperatures of that environment, which are notably distinct from those of tropical latitudes even before they penetrated the European subcontinent. Yet, from reports of analysts like Holliday, we get earliest complete European specimens displaying virtually identical body proportion indices to those of recent tropical Africans, and while change does occur, it largely starts to take place in late Paleolithic and Mesolithic remains, which still exhibit higher body proportion indices than recent Europeans! 

If the ancestors of early modern Europeans used the central Asian corridor, then that area could not have been one of a long refuge. However, if the ancestors of early Europeans either used the "Middle Eastern" corridor [which is right next door to Africa] or arrived directly from African soil, then one would expect them to still display "African-like body proportions". So where does that leave us? Does it tell us that they arrived from the "Midde East" or Africa? Well, given the location of the "Middle East", one would expect "intermediate" body proportion means across recent populations therein. 

This intermediacy may be a function of genetic exchanges between groups with recent African history and those with ancestry from northern Eurasians from more distant cooler temperate latitudes. The environment of that region itself still sports considerable temperature [with much of the area covered with hot desert; however, it should be noted that in deserts of the sort, temperatures can sharply fluctuate between extreme temperatures of hot and cold. Peek here (click) for global temperature distribution], which appears to be the main factor behind body proportions, as opposed to UV radiation. Given this, the natural body proportion continuum of this region may not be that far off from those seen in the tropics. How can one confirm this? 

Perhaps, by turning to body proportion indices reported for the earliest anatomically modern specimens of that region that predate paleontological record of anatomically modern humans in Europe, an estimation can be made thereof, of the possible autochthonous body proportions correlative to the temperatures of that region. But even here, one cannot be certain of how long the groups involved had been residing in the region, and then there are paleontological clues of Neanderthal presence in the Levant [e.g. post-cranial remains of the Kebara Cave], all factors which make it uncertain that any genuine estimation of body proportion indices, as natural response respective to the environment therein, can be made at all; nevertheless, the predominating patterns of available fossil record from her might prove instructive:

The Skhul cave has reportedly produced sufficiently complete fossil remains that have produced crural index values comprising 89, 86 and 80 [in percentages; D. Frayer (1992) ]. The low value of 80 corresponds to that of Skul 5, which not coincidentally, has been a subject of theories of Neanderthal genetic incursion. Clearly this is a fairly small sample size [just 3 values] to make any concrete assessment on the true state of affairs, but if the prevailing values [meaning, that determined around the expected cutoff values of "tropical body" and "cold-adapted" indices respectively] are anything to go by, then the high indices are suggestive of "tropical-like" body proportions. Presumably based off Frayer's (1992) reports, what looks to be that of Cro-Magnon 1 ("Old man"), the first of the fossil remains of the so-called series, turned up a crural index of 88, a value that stands in clear contrast to that "Caucasian" image that the specimen is associated with in various quarters, since as noted before, the "Caucasians" of Europe of today have markedly lower indices. At any rate, it seems that Stringer and Gamble did just that; went with the predominant range of the available dataset:
The skeletons of the Skhul and Qafzeh samples are even more modern than their skulls. And in contrast to the Neanderthals, their body proportions are tropical rather than cold-adapted, with long forearms and tibiae [high crural and brachial indices--grm] and an a average stature of about 1.83 m" - Chris Stringer and Clive Gamble, In Search of the Neanderthals, 1993.
Well, data seems to be scarce on early modern human remains of the "Middle East", and going by the fairly limited information available, one would have to assume that "tropical body" dominated the region in the time frame in question. This though, still doesn't say much about the sort of dominant adaptive responsive, in terms of body proportion index, that would be natural to that environment. Given this, if one were to choose an area where data is more complete and certain on this issue, then the recent African origin hypothesis of the earliest modern humans of Europe cannot be ruled out!

On other data, like the Paglicci DNA tests undertaken by Caramelli et al. (2003), again the dataset is fairly small to draw any solid conclusion on the true picture of the early anatomically modern humans of the Europe, not to mention the questions that still abound the reports. Going off on those reports, some might argue that a "Near Eastern" origin can be put forward, especially given the DNA patterns of recent Europeans. The idea here, is that if the so-called Cro-Magnons, otherwise EEMHs, are to be considered the monophyletic ancestors of recent Europeans, then they would have to have carried the same lineages or clades. That's logical enough, and perhaps can support the relative stronger limited informative report on the Paglicci-25 sequence, as opposed to the Paglicci-12, for which, from the information given, there is very little going on, let alone one that unequivocally verifies that its phylogenetic place lies within the clade that the research team said it belonged.

Even if one were to accept that the findings are unequivocal, the presence of hg N in the specimen does not rule out a possible African source, since the clade has been located in different areas of the continent [albeit generally explained off as 'back-migration', and in some cases, questionably so, as already discussed]. So, as it stands, more information is welcome, so as to come to a definitive conclusion between the two main choices presented herein, but whatever the case may be, it is clear that these early modern humans more physically resembled tropical Africans than recent Europeans, and far from representing any ideal "Caucasian race". What people call "White skin" or "White people" in the "Western" world came about fairly recent in human biohistory, dating not too far beyond the spread of Neolithic farming subsistence in Europe!

Be on the lookout for possible future updates.

—H. Rougler et al. (2007), Pes¸tera cu Oase 2 and the cranial morphology of early modern Europeans.

—Caramelli et al. (2003), Evidence for a genetic discontinuity between Neandertals and 24,000-year old anatomically modern Europeans.

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

—Erik Trinkaus (2007), European early modern humans and the fate of Neanderthals.

—Richards et al. (2000), Tracing European Founder Lineages in the Near Eastern mtDNA Pool.

—Richards et al. (2003), Extensive Female-Mediated Gene Flow from Sub-Saharan Africa into Near Eastern Arab Populations.

—Hans-Jurgen Bandelt (2005), Mosaics of ancient mitochondrial DNA: positive indicators of nonauthenticity.

—Hans-Jurgen Bandelt et al. (2003),  Native American mtDNA caveats.

—Yong-G. Yao et al. (2003), To Trust or Not to Trust an Idiosyncratic Mitochondrial Data Set.

—Quintana-Murci et al (1999), Genetic evidence of an early exit of Homo sapiens sapiens from Africa through eastern Africa.

—Sarah Tishkoff (2007), History of Click-Speaking Populations of Africa Inferred from mtDNA and Y Chromosome Genetic Variation.

—Kivisild et al. (2004), Ethiopian Mitochondrial DNA Heritage: Tracking Gene Flow
Across and Around the Gate of Tears

—Hassan et al.'s (2008), Y-Chromosome Variation Among Sudanese: Restricted Gene Flow, Concordance With Language, Geography, and History.

—Maca-Meyer et al. (2003), Mitochondrial DNA transit between West Asia and North Africa inferred from U6 phylogeography.

—J.R. Luis et al. (2004), The Levant versus the Horn of Africa: Evidence for Bidirectional Corridors of Human Migrations.

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

—Semino et al. (2004), Origin, diffusion, and differentiation of Y-chromosome haplogroups E and J: inferences on the neolithization of Europe and later migratory events in the Mediterranean area.

—Cruciani et al. (2004), Phylogeographic Analysis of Haplogroup E3b (E-M215) Y Chromosomes Reveals Multiple Migratory Events Within and Out Of Africa.

—A. Pyle et al. (2005), Mitochondrial DNA haplogroup cluster UKJT reduces the risk of PD; references - [17 ] Macaulay V, Richards M, Hickey E, et al. The emerging tree of West Eurasian mtDNAs: a synthesis of control-region sequences and RFLPs. Am J Hum Genet 1999; and [19] Herrnstadt C, Elson JL, Fahy E, et al. Reduced median network analysis of complete mtDNA coding region sequences for the major African, Asian, and European haplogroups. Am J Hum Genet 2002.

—Robert G. Franciscus (1999), Neandertal nasal structures and upper respiratory tract ‘‘specialization’’.

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

—Holliday et al. (2009), Body proportions of circumpolar peoples as evidenced from skeletal data: Ipiutak and Tigara (Point Hope) versus Kodiak Island Inuit.

—David Frayer (1992), Evolution at the European Edge: Neanderthal and Upper Paleolithic Relationships. Prehist. Europ. 2, pp. 9–69.

—Chris Stringer and Clive Gamble (1993), In Search of the Neanderthals.

—Cadenas et al. (2007), Y-chromosome diversity characterizes the Gulf of Oman. 

—Personal notes elsewhere from 2005, 2006, 2007, 2009 and 2010.

1 comment:

The Big Valley said...

Another excellent write-up. Thanks for documenting all this data, especially digging into the details and laying bare the thinly veiled, and thinly supported assumptions of many. Too often by constant cross citation they seek to establish such thin gruel as "fact." As you have shown, that is certainly not the case.