posted 28 October 2004 03:13 PM            

Exploring northeast African metric craniofacial variation at the individual level: A comparative study using principal components analysis.

Keita SO.

National Human Genome Center at Howard University, Anthropology Department, Smithsonian Institute, Washington, DC 20060.

posted 28 October 2004 09:07 PM            

Maca-Meyer et al.

BMC Genetics 2003, 4:15

"On the basis of complete mtDNA sequences, it has been proposed that U6 lineages, mainly found in North Africa, are the signatures of a return to Africa around 39,000 to 52,000 ya."

Am J Hum Biol. 2004 Nov-Dec;16(6):679-89.

Exploring northeast African metric craniofacial variation at the individual level: A comparative study using principal components analysis.

Keita SO.

National Human Genome Center at Howard University, Anthropology Department, Smithsonian Institute, Washington, DC 20060.

posted 28 October 2004 09:29 PM            

Constrast with Out of Europe "Caucasoid" anthropology concepts.

wikimediag.org

posted 29 October 2004 12:34 AM            

quote:

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Originally posted by supercar:
Good info. The only person I am aware of, who dismisses Keita's findings, and puts unfounded labels on him, is Orionix.

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posted 29 October 2004 03:26 AM            

quote:

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Originally posted by Thought2:
Mitochondrial DNA transit between West Asia and North Africa inferred from U6 phylogeography

Maca-Meyer et al.

BMC Genetics 2003, 4:15

"On the basis of complete mtDNA sequences, it has been proposed that U6 lineages, mainly found in North Africa, are the signatures of a return to Africa around 39,000 to 52,000 ya."

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Is this U6 lineage represented by the current Caucasian groups/peoples of North Africa i.e. some (white) Berber-speaking peoples? If so are these the same as/part of the "northern coastal people" talked about by SO Keita in previous studies?

quote:

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Originally posted by Thought2:
...Migration and gene flow at a later time is an issue......(But as previously noted, the M35 lineage was taken into the Near East before the Neolithic perhaps by pre-proto-Semitic speakers).......It is important to say there is no evidence to suggest that in the Holocene population replacement occured in any of these regions as a wholebased on the Y Chromosome data. Populations should be viewed processually as dynamic entities over time and not "static" entities. The presence of M35/215 lineages and the Benin sickle cell variant in southern Europe illustrates this well.....For the history of ideas, the diversity in the craniometric patterns in northeastern Africa, and the distribution of PN2 daughter lineages, render as falsified aspects of Seligman's "Hamitic hypothesis" and subsequent hypothesis consciously or unconsciously based on it. "

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From what I have read/misread(not to sure about this!)these two studies combine to suggest that there was a back migration from Western Asia(Near East) about 39-52K ya but(in the second study)it didn't happen again during the Holocene i.e. the last 11,000 years. Does the "Hamitic hypothesis" postulate another back migration occurring during the Holocene? How exactly does "the diversity in the craniometric patterns in northeastern Africa" falsify certain aspects of the Hamitic hypothesis? Couldn't the same diversity show admixture instead?

posted 29 October 2004 02:49 PM            

Thought Writes:

I am not sure how you are defining “Caucasian”? Some people define “Caucasian” based upon hard body parts and others base the usage of this term on soft body parts. Berber is a language and Berber speakers are diverse. U6 and her sub-lineages are found in populations as diverse as Nigeria, Senegal and the Canary Islands.

Limb ratio studies indicate that European populations were tropically adapted as late as the Mesolithic period. Paleolithic Nile Valley remains (the proposed entry point of U6) have affinities with modern “Negro”/Central African groups.

{If so are these the same as/part of the "northern coastal people" talked about by SO Keita in previous studies?}

Thought Writes:

No, as Keita mentions, the introduction of U6 into Africa dates to a time when modern ethnic/”racial” groups didn’t even exist. Especially “Caucasians”. Keita’s “Northern Coastal” types date to the late mid-Holocene, not 30,000 + B.C.

{Does the "Hamitic hypothesis" postulate another back migration occurring during the Holocene?}

Thought Writes:

Yes.

{How exactly does "the diversity in the craniometric patterns in northeastern Africa" falsify certain aspects of the Hamitic hypothesis?}

Thought Writes:
The time date and location (Kenya for example) narrow faced, narrow nosed African’s, in conjunction with current data on Y Chromosome male lineage OUT migrations from east Africa during the Holocene negate this concept. In fact, the bulk of the genetic diversity found in North Africa seems to date to the Greco-Roman and Arab/Islamic period.

Thought Posts:

Genetic Evidence for the Expansion of Arabian Tribes into the Southern Levant and North Africa

American Journal of Human genetics
70:1594 -1596, 2002

Nebel et al.

“In light of these historical data, it is not surprising to find, among the Berbers and contemporary Saharawis of northern Africa, Y Chromosomes that may have been introduced by recurrent waves of invaders from the Arabian Peninsula.”

posted 29 October 2004 02:52 PM            

quote:

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Originally posted by Thought2:
In fact, the bulk of the genetic diversity found in North Africa seems to date to the Greco-Roman and Arab/Islamic period.

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Thought writes:

Correction:

posted 29 October 2004 10:05 PM            

quote:

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Originally posted by Thought2:
{Is this U6 lineage represented by the current Caucasian groups/peoples of North Africa i.e. some (white) Berber-speaking peoples?}

Thought Writes:

I am not sure how you are defining “Caucasian”? Some people define “Caucasian” based upon hard body parts and others base the usage of this term on soft body parts. Berber is a language and Berber speakers are diverse. U6 and her sub-lineages are found in populations as diverse as Nigeria, Senegal and the Canary Islands.

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By "Caucasian"(?) Berber speakers I was referring to the lighter-skinned Berber groups such as the Kabyle.I am also aware that Berber speakers are diverse including such darker-skinned groups as the Haratin; needless to say their physical appearance is distinct.

quote:

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Originally posted by Thought2:
Limb ratio studies indicate that European populations were tropically adapted as late as the Mesolithic period. Paleolithic Nile Valley remains (the proposed entry point of U6) have affinities with modern “Negro”/Central African groups.

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Are you suggesting that the physical features of groups such as the Kabyle were developed later in the North African area rather than earlier on(in the Near East) before the back migration?
What is the scientific evidence for a tropically adapted European population until the Mesolithic?

quote:

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Thought Writes:
The time date and location (Kenya for example) narrow faced, narrow nosed African’s, in conjunction with current data on Y Chromosome male lineage OUT migrations from east Africa during the Holocene negate this concept. In fact, the bulk of the genetic diversity found in North Africa seems to date to the Greco-Roman and Arab/Islamic period.

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What is the time frame of this "OUT migration"? I suppose it coincides with the spread of Afro-Asiatic languages.

posted 30 October 2004 01:03 AM            

Thought Writes:

I agree, Kayabele do indeed have a distinct morphology from Tuareg, Haratin and the Siwa, Garamante, etc.

quote:

Originally posted by Thought2:
Limb ratio studies indicate that European populations were tropically adapted as late as the Mesolithic period. Paleolithic Nile Valley remains (the proposed entry point of U6) have affinities with modern “Negro”/Central African groups.

{Are you suggesting that the physical features of groups such as the Kabyle were developed later in the North African area rather than earlier on (in the Near East) before the back migration?}

Thought Writes:

No, I am suggesting that North Africa has seen an expansion of Eurasian genes and phenotypes BEGINNING with the Carthaginian period.

{What is the scientific evidence for a tropically adapted European population until the Mesolithic?}

Thought Posts:

Brachial and crural indices of European Late Upper Paleolithic and Mesolithic humans

T.W. Holliday,
Department of Anthropology,
Tulane University, New Orleans, LA 70118,

Among recent humans brachial and crural indices are positively correlated with mean annual temperature, such that high indices are found in tropical groups. However, despite inhabiting glacial Europe, the Upper Paleolithic Europeans possessed high indices, prompting Trinkaus (1981) to argue for gene flow from warmer regions associated with modern human emergence in Europe. In contrast, Frayer et al. (1993) point out that Late Upper Paleolithic and Mesolithic Europeans should not exhibit tropically-adapted limb proportions, since, even assuming replacement, their ancestors had experienced cold stress in glacial Europe for at least 12 millennia. This study investigates three questions tied to the brachial and crural indices among Late Pleistocene and recent humans. First, which limb segments (either proximal or distal) are primarily responsible for variation in brachial and crural indices? Second, are these indices reflective of overall limb elongation? And finally, do the Late Upper Paleolithic and Mesolithic Europeans retain relatively and/or absolutely long limbs? Results indicate that in the lower limb, the distal limb segment contributes most of the variability to intralimb proportions, while in the upper limb the proximal and distal limb segments appear to be equally variable. Additionally, brachial and crural indices do not appear to be a good measure of overall limb length, and thus, while the Late Upper Paleolithic and Mesolithic humans have significantly higher (i.e., tropically-adapted) brachial and crural indices than do recent Europeans, they also have shorter (i.e., cold-adapted) limbs. The somewhat paradoxical retention of 'tropical' indices in the context of more 'cold-adapted' limb length is best explained as evidence for Replacement in the European Late Pleistocene, followed by gradual cold adaptation in glacial Europe.

{What is the time frame of this "OUT migration"? I suppose it coincides with the spread of Afro-Asiatic languages.}

Thought Writes:

TMRCA for the dispersal of E-M78 in Europe POST DATES 12,000 B.C and PREDATES the Neolithic. So YES it does seem to coincide with the dispersal of the Afro-Asiatic languages.

posted 30 October 2004 01:06 AM            

Here is another new one from Keita:

Nat Genet. 2004 Nov;36 Suppl 1:S17-20.

Conceptualizing human variation.

Keita SO, Kittles RA, Royal CD, Bonney GE, Furbert-Harris P, Dunston GM, Rotimi CN.

[1] National Human Genome Center, College of Medicine, Howard University, Washington, DC 20060, USA. [2] Department of Anthropology, Smithsonian Institution, Washington, DC, USA.

What is the relationship between the patterns of biological and sociocultural variation in extant humans? Is this relationship accurately described, or best explained, by the term 'race' and the schema of 'racial' classification? What is the relationship between 'race', genetics and the demographic groups of society? Can extant humans be categorized into units that can scientifically be called 'races'? These questions underlie the discussions that address the explanations for the observed differences in many domains between named demographic groups across societies. These domains include disease incidence and prevalence and other variables studied by biologists and social scientists. Here, we offer a perspective on understanding human variation by exploring the meaning and use of the term 'race' and its relationship to a range of data. The quest is for a more useful approach with which to understand human biological variation, one that may provide better research designs and inform public policy.

posted 30 October 2004 10:34 AM            

quote:

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Originally posted by rasol:
Thought: Are you aware of similar studies that have attempted to locate the timeframe for the majority of Eurasian mtdna derivation in the Nile Delta?

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Thought Posts:

Am J Hum Biol. 2004 Nov-Dec;16(6):679-89.
Exploring northeast African metric craniofacial variation at the individual level: A comparative study using principal components analysis.

Keita SO.

National Human Genome Center at Howard University, Anthropology Department, Smithsonian Institute, Washington, DC 20060.

posted 30 October 2004 08:50 PM            

quote:

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Originally posted by ausar:
Thought, what about isolated populations like the Mzab and Shawia? What about the Souss Imazigh[Berbers] in southern Morocco. They seem to carry to signiture u6 also alongside with the African L series halpotypes.

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Thought Writes:

Indeed, U6 seems to be indicative of NW African origin. Of course all Amazigh speakers do NOT live in NW Africa. In fact, modern linguistic analysis places Amazigh as a branch of the Afro-Asiatic language phylum. Based upon glottochronology, the Afro-Asiatic language phylum is rooted between the area of the SE Sahara and the Horn of Africa. NW African Berber male linages are typified by the Haplogroup E-M81, which has TMRCA of 6,600 B.C.

Am J Hum Biol. 2004 Nov-Dec;16(6):679-89.
Exploring northeast African metric craniofacial variation at the individual level: A comparative study using principal components analysis.

Keita SO.

National Human Genome Center at Howard University, Anthropology Department, Smithsonian Institute, Washington, DC 20060.

"A modified version of the climatic hypothesis of Hiernaux (1975), coupled with consideration of drift/founder effect in a metapopulation model involving colonization and dessication cycles in the fragmented habitat of the Holocene Sahara, and other regions, likely help explain the dispersion of the subclades of PN2 and differential survival of various sublinages in various populations."