The M78, an Afro-Asiatic Y chromsome

Anyone who reads through the genetic studies of North and east Africa will notice that admixture between Eurasian and indigenous Africa groups is routinely mentioned, measuring the amount of gene flow between the two groups. E3b1 has recently been redefined as North African by Cruciani, so the older papers describing it as sub Saharan are incorrect, and a new term for it should be found.

Given its North African place of origin, M78 can no longer be attributed to a sub Saharan origin, particularly in light of the fact that it is rarely seen in sub Saharan populations without its maternal Eurasian partner M1. North Africa, circa 20,000 year ago, just prior to M78’s birth had just seen a wave of Eurasian settlers (R1b Y DNA, mtDNA types M, U, J/T, H and V) that had about 10,000 years prior wiped out the previous inhabitants as effectively as the Europeans had wiped out the Neanderthals. Who inhabited North Africa prior to this is something of a mystery, as they didn’t leave any mt or Y DNA signature in the modern population. The few very ancient remains from this area are very archaic in appearance, to the point of being misclassified as Neanderthal on occasion.

So it would seem M78 is a son of both African and Eurasian ancestry. It is particularly closely associated with the Eurasian M1 mt DNA in upper Egypt and Ethiopia, suggesting that M1 accompanied it into its journey south east, and back into Asia; something made more likely by the observation that M1 entered Africa via the North much earlier than it appeared in the South.

So this would make attempting to place M78 into Caucasian North African Y chromosome groups or typically sub Saharan groups both inaccurate and misleading. M78 is inherently a ‘mixed’ child, with ancestry from both sides. The same should probably be applied to the M1 mt DNA type in Africa. It appears to be inextricably linked with a large amount of African ancestry, and calling it ‘Eurasian’ doesn’t really reflect the ancestry of its carriers.

M78 also appears to be very closely associated with the spread of Afro-Asiatic languages; probably marking their arrival into the Levant and East Africa in ancient times.

In the light of this I would suggest that the description of Ethiopians as 40%  Eurasian and 60% sub Saharan is a poor description of their ancestry, and assigning the term ‘Afro-Asiatic’  to their M78 Y chromosomes and M1 mt DNA would be more appropriate.

This would make Upper Egyptians 28.8% paternally Afro-Asiatic, and maternally 17.6%  (23.2% average)Afro-Asiatic. Ethiopians would be about 38% paternally Afro-Asiatic, and maternally 17% Afro-Asiatic (27.5% average), with Somalis tracing 77.6% of their Y chromosomes to Afro-Asiatic ancestors, and 11% to Afro-Asiatic mothers (44.3% average). The difference between the Somali and Ethiopians would seem to be that Ethiopia has been more influenced by input from the Arabian area since the Neolithic. The addition of Arabian Y chromosomes has probably impacted significantly on the frequency of M78 in Ethiopia, explaining its lower frequency there than in Somalia. This won’t make much impact on the overall amount of Eurasian ancestry in Ethiopia (since I suspect the U mt DNA in Ethiopia also dates to the Afro Asiatic era). But it might suggest that Somali Eurasian ancestry is higher than thought if E3b1 is partly Asiatic in ancestry.

This would probably explain why the Somalis are the sub Saharan population with the most similarities to the Badarian Egyptian samples. They have more Afro-Asiatic ancestry, about 44%, having not experienced the Neolithic Arabic population expansion to the same degree, and with less Bantu contribution. A few of the older sources have described some of the Badari crania (and modern Upper Egyptians too) as being similar to some Somalian skulls. Which would hardly be surprising as Somalis retain a large signature from the expansion from Egypt, plus a significant amount of mostly east African DNA (about 43%, mostly maternal) and a little Arabian ancestry (overall about 13%). Although, whether this would mean Somalis look a bit like very ancient upper Egyptians or vice versa is a POV issue.

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Egyptians are not Arabs, they are Egyptians.

Modern Upper Egyptians

A strange title for a blog entry I know. But this is a result of a little nosing through the DNA studies available of modern Egypt, and some irritation at modern Egyptians being incessantly called ‘thieving Arabs’ by on-line Afrocentrists.

This is more focussed on the Egyptians around Luxor, where old upper Egypt was located. A recent DNA study by Cruciani that focused on the Y chromosome E-M78 revealed that it was ‘born’ in North East Africa , not East Africa as previously thought. This means, that an Egyptian with an m78 Y chromosome has had a male line ancestry reaching back to the Pleistocene inhabitants of Egypt; as far back as the Halfan culture about 24,000 years ago.

Southern Egyptians Y Chromomses are mainly native to Africa, both sub and supra Saharan. This makes a grand total of 80.3% definitively African non-Arab ancestry in the upper Egypt region. Y chromosomes possibly attributable to Arab males are very much in the minority in this area. A rough estimate (since no women invaded Egypt) is that about 5% or less of this population are from non dynastic Egyptian peoples, and not all of these would be Arabs.

Northern Egyptians are a bit more cosmopolitan in their ancestry  64.8% indigenous African. About 20% of the Y chrom0somes are near Eastern in origin, and 10.5 % are R Y chromosomes. However, some of these near eastern and European Y chromosomes show an ancient entry to Africa (G, K2, R1, R1b are 8,000 BP and older) and any historical contribution from foreign men is more likely to be in the 15% area. Divided by two (no recent female contribution to speak of). This makes non-dynastic Egyptian population around the 7% mark in Lower Egypt; and only some of this is Arab.

As for the maternal inheritance; this is more varied. From a study at Gurna (of modern upper Egyptians):

H 14.7%, I  5.9%, J   5.9%, L1a   11.7%, L1e   5.9%, L2a   2.9%, M1   17.6%, N1b   8.8%, T   5.9%, U   8.8%  U3   2.9%, U4   5.9% ,L3*(a)  5.9%, L3*(b)  2.9%, Other   2.9%.

Of these, the L haplotypes are typically sub Saharan (23.7%), M1 and U are ancient Eurasian, present at least 30,000 years and many of the other Eurasian haplotypes have been found in 12,000 year old bones in Morocco. The N an I  are possibly attributable to Arab ancestry, about 15% non-Arab in upper Egypt. But still, most of that would easily be attributable to the Neolithic input from Asia- and very little of this would be attributable to Arabs

To sum up, there doesn’t seem to be majority ‘Arab’ genetic component to the Egyptian DNA pool,  20% absolute maximum. And a lot of the non African DNA is traceable to the Neolithic farming expansion that swept across North Africa, so it would be a lot lower in reality.

In upper Egypt a maximum of 20% of the Y chromosomes are non African (the Mt DNA has been shown to be the same since dynastic times from Nubian mummy studies).. so how these people are supposed to have magically changed appearance in the past few thousand years with so little foreign input I’d like to know.

Egyptians are Egyptian, not Arab.

Very simplified Y chromosome information from Lucotte 2003.

Variation in Ancient Egyptian Stature and Body Proportions

Variation in Ancient Egyptian Stature and Body Proportions
Sonia R. Zakrzewski*

Stature and the pattern of body proportions were investigated in a series of six time-successive Egyptian populations in order to investigate the biological effects on human growth of the development and intensi-
fication of agriculture, and the formation of state-level social organization. Univariate analyses of variance were performed to assess differences between the sexes and among various time periods. Significant differences were found both in stature and in raw long bone length measurements between the early semi-pastoral population and the later intensive agricultural population. The size differences were greater in males than in females. This disparity is suggested to be due to greater male response to poor nutrition in the earlier populations, and with the increasing development of social hierarchy, males were being provisioned preferentially over females. Little change in body shape was found through time, suggesting that all body segments were varying in size in response to environmental and social conditions. The change found in body plan is suggested to be the result of the later groups having a more tropical (Nilotic) form than the preceding populations. .

Which would suggest a group adapting to the local condtions, and not totally indigenous to the area.

CONCLUSIONS
This study found an increase in stature within Egyptians from the Predynastic until the start of the Dynastic period, followed by a later decline in height. The increase in stature with intensification of agriculture was predicted as a result of greater reliability of food production and the formation of social ranking. The later decrease in stature coincides with even greater social complexity, and is expected as it implies that the formation of social classes is allied to differential access to nutrition and healthcare, with the higher ranked individuals being preferentially treated and fed. This change in stature was much greater in males than in females. Long bone lengths also increased from the Badarian to the Early Dynastic periods more for males than for females, and again decreased to a greater extent through the OK and MK periods among males than females. This greater response to changes in socioeconomic status by males was previously described in modern children (Malina et al., 1985; Stinson,
1985). The present study thus supports the greater response to environmental stresses, including positive stresses, in males than in females. The present study suggests that changes in stature and body size occurred in Egypt with the development of social ranking, through a reflection of differential access to food and other resources. These results must remain provisional due to the relatively small sample sizes and the lack of skeletal material that cross-cuts all social and economic groups within each time period. Further research on recently excavated skeletal material is therefore needed to further address the issues raised.

Mt DNA Analysis of Nile River Valley Populations

So, I admit having posted this before, but I couldn’t find the whole item. Now I have.

mtDNA Analysis of Nile River Valley Populations: A Genetic Corridor or a Barrier to Migration?

To assess the extent to which the Nile River Valley has been a corridor for human migrations between Egypt and sub-Saharan Africa, we analyzed mtDNA variation in 224 individuals from various locations along the river. Sequences of the first hypervariable segment (HV1) of the mtDNA control region and a polymorphic HpaI site at position 3592 allowed us to designate each mtDNA as being of “northern” or “southern” affiliation. Proportions of northern and southern mtDNA differed significantly between Egypt, Nubia, and the southern Sudan. At slowly evolving sites within HV1, northern-mtDNA diversity was highest in Egypt and lowest in the southern Sudan, and southern-mtDNA diversity was highest in the southern Sudan and lowest in Egypt, indicating that migrations had occurred bidirectionally along the Nile River Valley. Egypt and Nubia have low and similar amounts of divergence for both mtDNA types, which is consistent with historical evidence for long-term interactions between Egypt and Nubia. Spatial autocorrelation analysis demonstrates a smooth gradient of decreasing genetic similarity of mtDNA types as geographic distance between sampling localities increases, strongly suggesting gene flow along the Nile, with no evident barriers. We conclude that these migrations probably occurred within the past few hundred to few thousand years and that the migration from north to south was either earlier or lesser in the extent of gene flow than the migration from south to north.

This is a good guide to how Eurasian ancestry tails off as you move South down the Nile. As it can be seen, it’s at about 20% in the Southern Sudan, roughly even in Nubia. This is a classic example of a clinal gradient in DNA.

The conclusion of the study was

Nonetheless, we can infer that the migration of northern mtDNA types to the south is older than the migration of southern mtDNA types to the north (or that there has been less gene flow from north to south than from south to north along the Nile River Valley) and that Egypt and Nubia have had more genetic contact than either has had with the southern Sudan. Moreover, we can tentatively infer that these migrations occurred recently enough to fall within the period of the documented historical record of human populations in the Nile River Valley. Thus, it is tempting to try to relate these migrations to specific historical events (Shaw and Nicholson 1995). For example, the migration from north to south may coincide with the Pharaonic colonization of Nubia, which occurred initially during the Middle Kingdom (12th Dynasty, 1991–1785 B.C.) and more permanently during the New Kingdom, from the reign of Thotmosis III (1490–1437 B.C.). The migration from south to north may coincide with the 25th Dynasty (730–655 B.C.), when kings from Napata in Nubia conquered Egypt. Of course, additional migrations documented during the Ptolemeic, Roman, and Arabic times are also likely to have contributed to the current distribution of mtDNA types along the Nile River Valley.

HLA molecular markers in Tuvinians

HLA molecular markers in Tuvinians: a population with both Oriental and Caucasoid characteristics

HLA class I and class II alleles have been studied for the first time in the Turkish-speaking Tuvinian population, which lives in Russia, North of Mongolia and close to the Altai mountains. Comparisons have been done with about 11,000 chromosomes from other worldwide populations, and extended haplotypes, genetic distances, neighbor joining dendrograms and correspondence analyses have been calculated. Tuvinians show an admixture of Mongoloid and Caucasoid characters, the latter probably coming from the ancient Kyrgyz background or, less feasibly, more recent Russian Caucasoid admixture. However, Siberian population traits are not found and thus Tuvinians are closer to Central Asian populations. Siberians are more related to Na-Dene and Eskimo American Indians; Amerindians (from nowadays Iberian–America) are not related to any other group, including Pacific Islanders, Siberians or other American Indians. The ‘more than one wave’ model for the peopling of the Americas is supported.

It’s an HLA study, and by it’s nature a bit unreliable as to population relationships. But it does seem to suggest that Southern native Americans have some HLA ancestry from another source. Maybe Aborigines HLA profiles should be compared.

HLA polymorphism in Bulgarians

HLA polymorphism in Bulgarians defined by high-resolution typing methods in comparison with other populations.

Ivanova M, Rozemuller E, Tyufekchiev N, Michailova A, Tilanus M, Naumova E.

Central Laboratory of Clinical Immunology, Medical University, Sofia, Bulgaria.

In the present study we analyzed for the first time HLA class I and class II polymorphisms defined by high-resolution typing methods in the Bulgarian population. Comparisons with other populations of common historical background were performed. Most HLA-A, -B, -DRB alleles and haplotypes observed in the Bulgarian population are also common in Europe. Alleles and haplotypes considered as Mediterranean are relatively frequent in the Bulgarian population. Observation of Oriental alleles confirms the contribution of Asians to the genetic diversity of Bulgarians. The use of high-resolution typing methods allowed to identify allele variants rare for Europeans that were correlated to specific population groups. Phylogenetic and correspondence analyses showed that Bulgarians are more closely related to Macedonians, Greeks, and Romanians than to other European populations and Middle Eastern people living near the Mediterranean. The HLA-A,-B,-DRB1 allele and haplotype diversity defined by high-resolution DNA methods confirm that the Bulgarian population is characterized by features of southern European anthropological type with some influence of additional ethnic groups. Implementation of high-resolution typing methods allows a significantly wider spectrum of HLA variation to be detected, including rare alleles and haplotypes, and further clarifies the origin of Bulgarians.

A DNA study which directly contradicts the laughable (and pulled from print) study by Arnaiz Villena that claimed Greeks were closley related to Ethiopians.

The evolution of human skin coloration

The evolution of human skin coloration

Skin color is one of the most conspicuous ways in which humans vary and has been widely used to define human races. Here we present new evidence indicating that variations in skin color are adaptive, and are related to the regulation of ultraviolet (UV) radiation penetration in the integument and its direct and indirect effects on fitness. Using remotely sensed data on UV radiation levels, hypotheses concerning
the distribution of the skin colors of indigenous peoples relative to UV levels were tested quantitatively in this study for the first time.

The major results of this study are: (1) skin reflectance is strongly correlated with absolute latitude and UV radiation levels. The highest correlation between skin reflectance and UV levels was observed at 545 nm, near the absorption maximum for oxyhemoglobin, suggesting that the main role of melanin pigmentation in humans is regulation of the effects of UV radiation on the contents of cutaneous blood vessels located in the dermis. (2) Predicted skin reflectances deviated little from observed values. (3) In all populations for which skin reflectance data were available for males and females, females were found to be lighter skinned than males. (4) The clinal gradation of skin coloration observed among indigenous peoples is correlated with UV radiation levels and represents a compromise solution to the conflicting physiological requirements of photoprotection and vitamin D synthesis.

The earliest members of the hominid lineage probably had a mostly unpigmented or lightly pigmented integument covered with dark black hair, similar to that of the modern chimpanzee. The evolution of a naked, darkly pigmented integument occurred early in the evolution of the genus Homo. A dark epidermis protected sweat glands from UV-induced injury, thus insuring the integrity of somatic thermoregulation. Of greater significance to individual reproductive success was that highly melanized skin protected against UV-induced photolysis of folate (Branda & Eaton, 1978, Science 201, 625–626; Jablonski, 1992, Proc. Australas. Soc. Hum. Biol. 5, 455–462, 1999, Med. Hypotheses 52, 581–582), a metabolite essential for normal development of the embryonic neural tube (Bower & Stanley, 1989, The Medical Journal of Australia 150, 613–619; Medical Research Council Vitamin Research Group, 1991, The Lancet 338, 31–37) and spermatogenesis (Cosentino et al., 1990, Proc. Natn. Acad. Sci. U.S.A. 87, 1431–1435; Mathur et al., 1977, Fertility Sterility 28, 1356–1360).

As hominids migrated outside of the tropics, varying degrees of depigmentation evolved in order to permit UVB-induced synthesis of pre-vitamin D3. The lighter color of female skin may be required to permit synthesis of the relatively higher amounts of vitamin D3 necessary during pregnancy and lactation.

Skin coloration in humans is adaptive and labile. Skin pigmentation levels have changed more than once in human evolution. Because of this, skin coloration is of no value in determining phylogenetic relationships among modern human groups.

Figure 1. The potential for synthesis of previtamin D3 in lightly pigmented human skin computed from annual average UVMED. The highest annual values for UVMED are shown in light violet, with incrementally lower values in dark violet, then in light to dark shades of blue, orange, green and gray (64 classes). White denotes areas for which no UVMED data exist. Mercator projection. In the tropics, the zone of adequate UV radiation throughout the year (Zone 1) is delimited by bold black lines. Light stippling indicates Zone 2, in which there is not suffcient UV radiation during at least one month of the year to produce previtamin D3 in human skin. Zone 3, in which there is not suffcient UV radiation for previtamin D3 synthesis on average for the whole year, is indicated by heavy stippling.

 

Figure 2. A comparison of the estimated areas in which annual UVMED is not sufficient, averaged over the year, to catalyze previtamin D3 synthesis in lightly, moderately and highly melanized skin. All zones were defined by the values for previtamin D3 synthesis potential presented in Table 2. Widely spaced oblique hachure covers the northernmost region of the Northern Hemisphere in which there is not sufficient UV radiation, averaged over the entire year, to catalyze the formation of previtamin D3 in lightly pigmented (Type IIIa) human skin (Zone 3 from Figure 1). Narrowly spaced oblique hachure denotes the area, in addition to that shown by widely spaced oblique hachure, in which there is not sufficient UV radiation to catalyze the formation of previtamin D3 in moderately melanized (Type V) skin. The large circum-Equatorial area denoted by stippling covers the area, in addition to the previous two, in which there is not sufficient UV radiation averaged over the entire year to catalyze the formation of previtamin D3 in highly melanized (Type VI)
skin.

Figure 3. Predicted shading of skin colors for indigenous humans based on the results of a linear regression model in which skin reflectance (at 685 nm) for indigenous peoples in both hemispheres was allowed to respond to annual average UVMED for both hemispheres. The predicted skin reflectance values were first divided into 50 equal intervals and then graphically represented in gray shades ranging from darkest gray (greatest melanization) to lightest gray (least melanization). Darker shades of gray represent a higher degree of skin melanization and do not represent actual predicted skin colors.

Figure 4. Gradation of skin colors for known indigenous human populations, represented by shading from darkest to lightest gray (greatest to least melanization, as in Figure 3), based on observed skin reflectances at 685 nm reported in Table 6.

Conclusions
The results presented here demonstrate that skin coloration in humans is highly adaptive and has evolved to accommodate the physiological needs of humans as they have dispersed to regions of widely varying annual UVMED. The dual selective pressures of photoprotection and vitamin D3 synthesis have created two clines of skin pigmentation. The first cline, from the equator to the poles, is defined by the significantly greater need for photoprotection at the equator in particular and within the tropics in general. Deeply melanized skin protects against folate photolysis and helps to prevent UV-induced injury to sweat glands(and subsequent disruption of thermoregulation). The second cline, from approximately 30N to the North Pole, is defined by the greater need in high latitudes to accommodate as much previtamin D3 synthesis as possible in areas of low annual UVMED. Humans inhabiting regionsat the intersection of these clines demonstrate a potential for developing varying degrees of facultative pigmentation (tanning) (Quevedo et al., 1975). Moderately melanized skin would appear to be at risk of vitamin D3 deficiency and rickets under conditions where UV radiation is restricted as a result of latitude, cultural practices or both.

The results of this study suggest that skin pigmentation is relatively labile, and that adaptations to local UVMED conditions can occur over relatively short periods of geological time. Thus, it is likely that some human lineages through time may have gone through alternating periods of depigmentation and pigmentation (or vice versa) as they moved from one UVMED regime to another. As the pace of human migrations has quickened in recent centuries, more and more populations are finding themselves living under UV irradiation regimes to which they are inherently poorly adapted (e.g., the English who settled in Australia in the nineteenth and twentieth centuries, and the Indians and Pakistanis who have moved to northern England in recent decades), with major public health consequences (Kaidbey et al., 1979; Henderson et al., 1987). Cultural practices such as sun-bathing and purdah have in some cases exacerbated these conditions and mitigated others. Because of its high degree of responsiveness to environmental conditions, skin pigmentation is of no value in assessing the phylogenetic relationships between human groups.

I’ve not heard about the pholysis of folate before. Interesting. That was one of the faults with the skin cancer/sunburn theory, it took effect after the reproductive years .

The Origin of the Baltic-Finns

Volume XLIII Number 2, Winter 2002
The Origin of the Baltic-Finns from the Physical Anthropological Point of View

Markku Niskanen1
University of Oulu, Finland
The author provides a comprehensive analysis of the physical anthropology of the Finns and Saami, comparing them with other Scandinavian peoples and contrasting them genetically with the Mongoloid peoples of Asia, notwithstanding the affinities which  link the Finnish language with the Uralic and to a lesser extent the Altaic languages. He concludes that both the Finns and the Saami are genetically Caucasoid or European, and that the Finns especially are closely akin to the other North European peoples of Scandinavia.

Introduction
It is impossible to reconstruct the origins of ethnic groups without information about their genetic relationships. This information provides knowledge about inter-population contacts, assists in determining the geographic areas of origins of the populations in question, and sometimes even reveals how long these populations have lived in their present territories. Therefore, these reconstructed genetic relationships can be used to test hypotheses and theories of ethnic origins based on linguistic and/or archeological evidence. In this article, craniometric and nuclear DNA data, as well as the findings of recent studies of mitochondrial DNA and Y-chromosomal DNA variation are used to determine whether the origin of the Baltic- Finns is better explained by the traditional migration theory or by the more recent settlement continuity theory. These two competing theories are reviewed briefly below.

This publication describes the Finns as typically European, and attributes their ‘Mongoloid characteristsics’ to retaining features from Upper Paleolithic Europeans. This really an ‘all you ever wanted to know about Finns’ paper.

Strong cheekbones and flaring zygomatic arches of many Finno- Ugrians, commonly and erroneously assumed to be Mongoloid features, are actually inherited from European Cro-Magnons (Coon 1939, Niskanen 1994b). These two “Paleo-European” features have survived especially well among the Finno-Ugrians of northern Europe because, as the archeological evidence presented by Zvelebil (1986) indicates, the subsistence transition from foraging to farming occurred more recently and with a lesser influx of immigrants in these marginal regions for agriculture than further south. Most other Europeans have been farmers for so many generations (eating soft bread, porridge, etc.) that their cheek bones (which provide attachments for the masseter muscle) have reduced in size in comparison to other parts of their facial anatomy.

Figure 2. Plot of sample means of the first (CAN1) and the second (CAN2) canonical discriminant function scores computed from c-scores of 42 craniofacial measurements. These two scores explain 70.04% of the total variance. CRO = Cro-Magnons, IRI = Irish, SCO = Scottish, ENG = English, SWE = Swedish, FIN = Finnish, SAA = Saami, GER = German, FRE = French, CZE = Czech, and RUS = Russian. This is the same set of variables than the one used to calculate Mahalanobis distances of Table 3 except that none of the raw measurements were used to compute indices.

Figure 1. A mirror image of dimension coefficient plot extracted from Mahalanobis distances between the European samples of Table 3 using the MDS-procedure. BRI = British (pooled English, Scottish, and Irish), NOR = Norwegian, SWE = Swedish, FIN = Finnish, SAA = Saami, GER = German, FRE = French, CZE = Czech, and RUS = Russian. Modified from Niskanen (1994a).

He also says..

These craniometric analyses demonstrate that the Finns (and presumably other Baltic-Finns) and Saami (although they form their own subset within the European set) possess North European craniofacial configuration with more than average amount of Paleo-European (Cro-Magnoid) features. This finding indicates that the Baltic-Finns and Saami (as well as their Scandinavian neighbors) are indigenous people of northern Europe and not recent immigrants from elsewhere (Niskanen 1998).

As it can be seen on fig 2, the Cro Magnons are an outlier to Northern European populations, but not wildly so. There being less distance between them and the Finns than there is between the Finns and the Russians.

It suggests that Finns and Saami’s don’t share a common origin, from DNA evidence.

The mtDNA studies (Sajantila et al. 1995, Lahermo et al. 1996) reveal that the non-Saami Finno-Ugrians of Europe (the Finns, Karelians, Estonians, Volga-Finns) have the same genetic origin as the non-Uralic-speaking Europeans, and that the Saami represent a unique and ancient sub-group of Europeans that had separated from the other Europeans over 10,000 years ago. Therefore, the Baltic-Finns (the Finns, Karelians, and Estonians) and the Saami do not appear to descend from a common ancestral population that lived as recently as a few thousand years ago. The genetic admixture between the Baltic-Finns and the Saami is also rather recent, but adequate enough to make the Finns and the Karelians the closest genetic relatives of the Saami.

Diversity and age of the four major mtDNA haplogroups in native America

Diversity and age of the four major mtDNA haplogroups, and their implications for the peopling of the New World.
S L Bonatto and F M Salzano,Departamento de Genética, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.  

Despite considerable investigation, two main questions on the origin of Native Americans remain the topic of intense debate-namely, the number and time of the migration(s) into the Americas. Using the 720 available Amerindian mtDNA control-region sequences, we reanalyzed the nucleotide diversity found within each of the four major mtDNA haplogroups (A-D) thought to have been present in the colonization of the New World. We first verified whether the within-haplogroup sequence diversity could be used as a measure of the haplogroup’s age. The pattern of shared polymorphism, the mismatch distribution, the phylogenetic trees, the value of Tajima’s D, and the computer simulations all suggested that the four haplogroups underwent a bottleneck followed by a large population expansion. The four haplogroup diversities were very similar to each other, offering a strong support for their single origin. They suggested that the beginning of the Native Americans’ ancestral-population differentiation occurred approximately 30,000-40,000 years before the present (ybp), with a 95%-confidence-interval lower bound of approximately 25,000 ybp. These values are in good agreement with the New World-settlement model that we have presented elsewhere, extending the results initially found for haplogroup A to the three other major groups of mtDNA sequences found in the Americas. These results put the peopling of the Americas clearly in an early, pre-Clovis time frame.

It’s nice to see a study that agrees with the older (40,000 years plus) dates that are seen in some American sites like Topper. Why the recent entry (13k) date is clung onto so fiercely by some I’ll never know.

Just a Niel Risch paper on population genetics.

Categorization of humans in biomedical research: genes, race and disease
Neil Risch,1,2 Esteban Burchard,3 Elad Ziv,3 and Hua Tang4

A debate has arisen regarding the validity of racial/ethnic categories for biomedical and genetic research. Some claim ‘no biological basis for race’ while others advocate a ‘race-neutral’ approach, using genetic clustering rather than self-identified ethnicity for human genetic categorization. We provide an epidemiologicperspective on the issue of human categorization in biomedical and genetic research that strongly supports the continued use of self-identified race and ethnicity.

 A major discussion has arisen recently regarding optimalstrategies for categorizing humans, especially in the United States, for the purpose of biomedical research, both etiologic and pharmaceutical. Clearly it is important to know whether particular individuals within the population are more susceptible to particular diseases or most likely to benefit from certain therapeutic interventions. The focus of the dialogue has been the relative merit of the concept of ‘race’ or ‘ethnicity’, especially from the genetic perspective. For example, a recent editorialin the New England Journal of Medicine [1] claimed that “race is biologically meaningless” and warned that “instruction in medicalgenetics should emphasize the fallacy of race as a scientific concept and the dangers inherent in practicing race-based medicine.” In support of this perspective, a recent article in Nature Genetics [2] purported to find that “commonly used ethnic labels are both insufficient and inaccurate representations of inferred genetic clusters.” Furthermore, a supporting editorial in the same issue [3] concluded that “population clusters identified by genotype analysis seem to be more informative than those identified by skin color or self-declaration of ‘race’.” These conclusions seem consistent with the claim that “there is no biological basis for ‘race'” [3] and that “the myth of major genetic differences across ‘races’ is nonetheless worth dismissing with genetic evidence” [4]. Of course, the use of the term “major” leaves the door open for possible differences but a priorilimits any potential significance of such differences.

In our view, much of this discussion does not derive from an objective scientific perspective. This is understandable, given both historic and current inequities based on perceived racial or ethnic identities, both in the US and around the world, and the resulting sensitivities in such debates. Nonetheless, we demonstrate here that from both an objective and scientific (genetic and epidemiologic) perspective there is great validity in racial/ethnic self-categorizations, both from the research and public policy points of view.

An interesting read, one that rather disproves the idea that genetics proves race is a social construct. but the real interesting bit to me was..

 For example, east African groups, such as Ethiopians and Somalis, have great genetic resemblance to Caucasians and are clearly intermediate between sub-Saharan Africans and Caucasians [5]. The existence of such intermediate groups should not, however, overshadow the fact that the greatest genetic structure that exists in the human population occurs at the racial level.

Most recently, Wilson et al. [2] studied 354 individuals from 8 populations deriving from Africa (Bantus, Afro-Caribbeans and Ethiopians), Europe/Mideast (Norwegians, Ashkenazi Jews and Armenians), Asia (Chinese) and Pacific Islands (Papua New Guineans). Their study was based on cluster analysis using 39 microsatellite loci. Consistent with previous studies, they obtained evidence of four clusters representing the major continental(racial) divisions described above as African, Caucasian, Asian, and Pacific Islander. The one population in their analysis that was seemingly not clearly classified on continental grounds was the Ethiopians, who clustered more into the Caucasian group. But it is known that African populations with close contact with Middle East populations, including Ethiopians and North Africans, have had significant admixture from Middle Eastern (Caucasian) groups, and are thus more closely related to Caucasians [14].

 … because I’m interested in Ethiopian DNA. Which backs up the use of the Mt DNA/Y DNA as genetic markers to measure racial admixture in populations, showing Ethiopians to be almost half Arab, essentially.

If anyone is suspicious of Dr Risch’s motives, he makes quite clear that his main concern is that a race/colour blind approach to medicine is that minority health-care will suffer.

Thus, results from such studies would be largely derived from the Caucasian majority, with obtained parameter estimates that might not apply to the groups with minority representation.

And quite right too. I had an accusation of a neo-Nazi eugenics motive thrown at a study of racial differences in gestation length who’s sole purpose was to lower the mortality rate of black and Asian babies in the UK.

Recognising racial differences saves lives.