Showing posts with label Yemen. Show all posts
Showing posts with label Yemen. Show all posts

October 16, 2012

Nubian Complex reduction strategies in Dhofar, southern Oman (Usik et al. 2012)

From the paper:
If there was no Nubian Complex occupation in Egypt during the MIS 5de5b hiatus, from where did the Egyptian Late Nubian, dating no earlier than MIS 5a, come? Did it spread north from Sudan or was there an expansion of Arabian Nubian Complex toolmakers back into Africa? Certainly, the striking similarities between the Classic Dhofar Nubian and Egyptian Late Nubian, as compared with the Sudanese Late Nubian, might indicate such a scenario. Again, greater chronological resolution in African and Arabian Nubian assemblages is required to answer these questions.   
It seems overly simplistic to expect the expansion of Nubian Complex toolmakers into Arabia was a single migration or event; rather, it was more likely a process of recurring bidirectional movements across the Red Sea linked to consecutive phytogeographic range expansions and contractions. At the same time, the presence of technologically distinct, non-Nubian industries elsewhere in Arabia from MIS 5a to MIS 3 indicates separate, autochthonous culture groups and/or input from other adjacent regions (Marks, 2009; Armitage et al., 2011; Petraglia et al., 2011; Delagnes et al., 2012). In the case of the Wadi Surdud stratified assemblages in Yemen, dated tow60e40 ka BP (Delagnes et al., 2012), and Jebel Faya successive assemblages B and A, bracketed within MIS 3 (Armitage et al., 2011), both archaeological sequences are thought to be the products of local lithic traditions. Clearly, Late Pleistocene demography in Arabia was far more complex than one population emanating from a single source area.   
For now, it is clear that the Afro-Arabian Nubian Complex exhibits a robust archaeological signature on both sides of the Red Sea, in terms of site density, distribution, and long-term technological variability, always based on the core principal of opposed platform exploitation. This is likely the result of populations who were well and truly established in their respective regions for an extended period of time. Perhaps we have made too much of tracking routes of expansion and the timing of sea crossings into Arabia. The Red Sea may be more of a barrier for scholars today than it ever was for humans in the Middle Stone Age. 
Related comment (my emphasis):

Nubian technology has been found in association with a modern human child within occupation Phase 3 at the site of Taramsa 1 in Egypt. Science would suggest they're modern. Unless, of course, one is willing to propose an entirely new species that occupied NE Africa 100,000 years ago? 
Nubian technology has now been identified in central Arabia (article in press by Crassard and Hilbert) and seems to be spread across central and eastern Yemen as well. The Mudayyan Industry, published in Usik et al. 2012, falls sometime after the Nubian occupation of Dhofar and is clearly derived from Nubian Levallois technology. Moreover, this particular technology governed by bidirectional recurrent Levallois blank production is interpreted as the transition from Middle Palaeolithic Levallois to Upper Palaeolithic blade reduction as exemplified at Initial Upper Palaeolithic sites in the Levant such as Boker Tachtit and Ain Difla. Essentially, the Nubians in Arabia have provided the technological missing link for the MP-UP transition in the Levant. 
So, Nubians entered Arabia sometime between 130 - 100 ka and appear to have subsequently expanded northward during the early MIS 3 wet phase that would have facilitated north-south demographic exchange throughout the Peninsula. As for the Out of Arabia expansion eastward, this is still anyone's guess. We can be sure it wasn't related to Nubian Complex toolmakers.

Quaternary International doi:dx.doi.org/10.1016/j.quaint.2012.08.2111

Nubian Complex reduction strategies in Dhofar, southern Oman

Vitaly I. Usik et al.

Between 2010 and 2012, the Dhofar Archaeological Project has located and mapped 260 Nubian Complex occurrences across Dhofar, southern Oman. Many of these lithic assemblages are technologically homologous to the Late Nubian Industry found in Africa, while others may represent a local industry derived from classic Nubian Levallois technology. The purpose of this paper is to describe the various reduction strategies encountered at a sample of Nubian Complex sites from Dhofar, to explore inter-assemblage variability, and, ultimately, to begin to articulate technological units within the “Dhofar Nubian Tradition.” To achieve this aim, we have developed an analytical scheme with which to describe variability among Nubian Levallois reduction strategies. From our analysis, we are able to discern at least two distinct industries within a regional lithic tradition. Demographic implications of the enduring Dhofar Nubian Tradition are considered in light of new evidence found throughout the Arabian Peninsula.

Link

August 29, 2012

Pre-Neolithic dispersals into Arabia

The harsh climate of Arabia, periodically interrupted by more "green" periods has probably meant that the population living there has occasionally been driven out as climate deteriorated, with new populations moving in as climate improved. In more recent times, technological invention (e.g., the camel, the deep water well, or even more recently the discovery of oil) has allowed people to subsist in the desert a little more "comfortably."

One interesting question is whether the current Arabian population derives entirely from early Levantine Neolithic peoples, or also from people who had ventured there prior to it. A new paper in AJPA suggests that living Arabians are not entirely the descendants of Neolithic peoples, but also preserve signals of pre-Neolithic input from the Near East, by studying the mtDNA haplogroup R2 (see map on left for its current distribution).

From the paper:

It is noteworthy, however, that these pre-Neolithic sites do not bear any technological traits analogous to Terminal Pleistocene (Epipalaeolithic) assemblages found in the Near East. The only germane possibility of a connection between Arabia and the Near East during this period comes from the Faw Well site at the western edge of the Rub’ Al Khali (Edens, 2001). Although undated, the Faw Well lithic assemblage bears a close resemblance to the Late Ahmarian of the Levant (20–17 ka). Perhaps it was this, or a subsequent pulse from the Levant, that provided the demographic input expressed by the genetic lineages documented in this article.   
The results from the three analyzed southern Arabian clades do not support population continuity from the first occupants more than 50 ka ago (Fernandes et al., 2012) but do suggest some continuity across the Pleistocene- Holocene boundary. Our analysis indicates that the observed population expansion 13–12 ka is probably the result of genetic input from the Near East a few thousand years before the (debated) arrival of the PPNB culture in Arabia. If, however, there was a population expansion southward through Arabia some 13–12 ka, we have not yet found its archaeological signatures. Both regions exhibit stone tool technologies with some overlapping features, so it is warranted to suppose that we may one day locate a firm link between southern Arabia and the Near East sometime during the Late Pleistocene. Given the vast amount of unexplored territory in Arabia and paucity of archaeological sites with numerical ages, future investigations (both archaeogenetical and archaeological) throughout the Peninsula will undoubtedly serve to shed more light on this question. 



American Journal of Physical Anthropology DOI: 10.1002/ajpa.22131

Pleistocene-Holocene boundary in Southern Arabia from the perspective of human mtDNA variation

Abdulrahim Al-Abri et al.

It is now known that several population movements have taken place at different times throughout southern Arabian prehistory. One of the principal questions under debate is if the Early Holocene peopling of southern Arabia was mainly due to input from the Levant during the Pre-Pottery Neolithic B, to the expansion of an autochthonous population, or some combination of these demographic processes. Since previous genetic studies have not been able to include all parts of southern Arabia, we have helped fill this lacuna by collecting new population datasets from Oman (Dhofar) and Yemen (Al-Mahra and Bab el-Mandab). We identified several new haplotypes belonging to haplogroup R2 and generated its whole genome mtDNA tree with age estimates undertaken by different methods. R2, together with other considerably frequent southern Arabian mtDNA haplogroups (R0a, HV1, summing up more than 20% of the South Arabian gene pool) were used to infer the past effective population size through Bayesian skyline plots. These data indicate that the southern Arabian population underwent a large expansion already some 12 ka. A founder analysis of these haplogroups shows that this expansion is largely attributed to demographic input from the Near East. These results support thus the spread of a population coming from the north, but at a significantly earlier date than presently considered by archaeologists. Our data suggest that some of the mtDNA lineages found in southern Arabia have persisted in the region since the end of the Last Ice Age.

Link

January 30, 2012

AAPA 2012 abstracts (part 1)

Here are some interesting abstracts from the 81st Annual Meeting of the American Association of Physical Anthropologists.


Maternal marks of admixture in Cape Coloreds of South Africa.
KRISTINE G. BEATY1, DELISA L. PHILLIPS1, MACIEJ HENNEBERG2 and MICHAEL H. CRAWFORD1.
Previous studies of genetic diversity have suggested that the Cape Coloureds of South Africa are a highly admixed population with genetic roots from indigenous African groups including Khoisans, and the later arrival of Bantu speaking Xhosa farmers. Further genetic contributions came during European colonization of South Africa, which added to the inclusion of largely male European markers to the gene pool. Slaves from Indonesia, Malaysia, Madagascar and India are also thought to have contributed to the genetic makeup of this ethnic group. This study examines the maternal contribution of each of these groups to the genetic diversity of the Cape Coloreds through sequencing of the hypervariable region I of the mitochondrial DNA and through restriction fragment length polymorphism.
A total of 123 individuals were examined for this study. High frequencies of haplogroups L1 and L2 were found at 81.3 percent in this group (100 of the 123 individuals), which indicates that this group has a large African contribution to its mitochondrial makeup. Restrictions of the major European haplogroups identified nine individuals, 7.3 percent of the sample, belonged to haplogroups I and J. Five individuals (4.1 percent of the sample) belonged to the superhaplogroup M, indicating that Asian slaves did contribute to the maternal gene pool. The majority of maternal lineages in this Cape Coloured sample are African in origin, with some European influence and a small contribution from Asian maternal lineages.

Ancient DNA reveals the population origin of the Eastern Xinjiang.
SHIZHU GAO2, HONGJIE LI1, CHUNXIANG LI1 and HUI ZHOU1,3.
Connecting with the Turpan Basin, the Eurasia steppe and the Gansu Corridor, the Eastern region of Xinjiang has played a significant role in the history of human migration, cultural developments, and communications between the East and the West. The population origin, migration and integration of this region have attracted extensive interest among scientists.
In order to research the population origin and movement of the Eastern Xinjiang, genetic polymorphisms studies of the Hami population were conducted. The Hami site is located in the East of Tian-Moutain in Xinjiang, dating back to the Bronze-early Iron Age. Archaeological studies showed that the culture of the Hami site possessed features from both the East and the West. Ancient mtDNA analysis showed that A, C, D, F, G, Z and M7 of the Eastern maternal lines, and W, U2e, U4, and U5aof the Western maternal lines were identified. Tajimas’D test and mismatch distribution analysis show that the Hami population had experienced population expansion in recent time. The demographic analysis of haplogroups suggests that the populations of the Northwest China, Siberia and the Central Asia have contributed to the mtDNA gene pool of the Hami population.
Our study reveals the genetic structure of the early population in Eastern Xinjiang, and its relationships with other Eurasian populations. The results will provide valuable genetic information to further explore the population origin and migration of Xinjiang and Central Asia.


Analysis of Chuvash mtDNA points to Finno-Ugric origin.
ORION M. GRAF1, STEPHEN M. JOHNSON1, JOHN MITCHELL2, STEPHEN WILCOX3, GREGORY LIVSHITS4 and MICHAEL H. CRAWFORD1.
A sample of 92 unrelated individuals from Chuvashia, Russia was sequenced for hypervariable region-I (HVR-I) of the mtDNA molecule. These data have been verified using RFLP analysis of the control region, revealing that the majority exhibit haplogroups H (31%), U (22%), and K (11%), which occur in high frequencies in western and northern Europe, but are virtually absent in Altaic or Mongolian populations. Multidimensional scaling (MDS) was used to examine distances between the Chuvash and reference populations from the literature. Neutrality tests (Tajima’s D (-1.43365) p<0.05, Fu’s FS (-25.50518) p<0.001) and mismatch analysis, which illustrates unimodal distribution, all suggest an expanding population.
The Chuvash speak a Turkic language that is not mutually intelligible to other extant Turkish groups, and their genetics are distinct from Turkic-speaking Altaic groups. Some scholars have suggested that they are remnants of the Golden Horde, while others have advocated that they are the products of admixture between Turkic and Finno-Ugric speakers who came into contact during the 13th century. Earlier genetic research using autosomal DNA markers indicated a Finno-Ugric origin for the Chuvash. This study examines uniparental mitochondrial DNA markers to better elucidate their origins. Results from this study maintain that the Chuvash are not related to Altaic or Mongolian populations along their maternal line, thus supporting the “Elite” hypothesis that their language was imposed by a conquering group —leaving Chuvash mtDNA largely of Eurasian origin. Their maternal markers appear to most closely resemble Finno-Ugric speakers rather than Turkic speakers.


An ancient DNA perspective on the Iron Age “princely burials” from Baden-Wurttemberg, Germany.
ESTHER J. LEE1, CHRISTOPH STEFFEN1, MELANIE HARDER1, BEN KRAUSE-KYORA1, NICOLE VON WURMB-SCHWARK2 and ALMUT NEBEL3.
During the Iron Age in Europe, fundamental social principles such as age, gender, status, and kinship were thought to have played an important role in the social structure of Late Hallstatt and Early Latene societies. In order to address the question of kinship relations represented in the Iron Age “princely burials” that are characterized by their rich material culture, we carried out genetic analysis of individuals associated with the Late Hallstatt culture from Baden-Wurttemberg, Germany. Bone specimens of thirty-eight skeletal remains were collected from five sites including Asperg Grafenbuhl, Muhlacker Heidenwaldle, Hirschlanden, Ludwigsburg, and Schodeingen. Specimens were subjected to DNA extraction and amplification under strict criteria for ancient DNA analysis. We successfully obtained mitochondrial DNA (mtDNA) control region sequences from seventeen individuals that showed different haplotypes, which were assigned to nine haplogroups including haplogroups H, I, K, U5, U7, W, and X2b. Despite the lack of information from nuclear DNA to infer familial relations, information from the mtDNA suggests an intriguing genetic composition of the Late Hallstatt burials. In particular, twelve distinct haplotypes from Asperg Grafenbuhl suggest a heterogeneous composition of maternal lineages represented in the “princely burials”. The results from this study provide clues to the social structure reflected in the burial patterns of the Late Hallstatt culture and implications on the genetic landscape during the Iron Age in Europe.


Genetic snapshot from ancient nomads of Xinjiang.
HONGJIE LI1, SHIZHU GAO2, CHUNXIANG LI1, YE ZHANG1, WEN ZENG3, DONG WEI3 and HUI ZHOU1,3.
Nomads of the Eurasian steppes are known to have played an important role in the transfer commodities and culture among East Asia, Central Asia, and Europe. However, the organization of nomadic societies and initial population genetic composition of nomads were still poorly understood because of few archaeological materials and written history.
In this study, the genetic snapshot of nomads was emerged by examining mitochondrial DNA and Y-chromosome DNA of 30 human remains from Heigouliang (HGL) site in the eastern of Xinjiang, which dated 2000 years ago and associated to the nomadic culture by archaeological studies. Mitochondrial DNA analysis showed that the HGL population included both East Eurasian haplogroups (A, C, D, G, F and Z) and West Eurasian haplogroups (H, K, J, M5 and H). The component of Eastern haplogroups is dominant. The distribution frequency and Fst values of Eastern haplogroups indicated the HGL population presented close genetic affinity to the nearby region modern populations of Gansu and Qinghai, while those of western haplogroups showed similar with Mongolia and Siberia populations. The results implied various maternal lineages were introduced into the HGL population. Regarding the Y chromosomal DNA analysis, nearly all samples belonged to haplogroup Q which is thought to be the mark of the Northern Asian nomads. We identified paternal kinship among three individuals at the same tomb by Y-STR marker.
Combined with archaeological and anthropological investigations, we inferred that the gene flow from the neighboring regions was possibly associated with the expansion of Xiongnu Empire.


Vikings, merchants and pirates at the top of the world: Y-chromosomal signatures of recent and ancient migrations in the Faroe Islands.
ALLISON E. MANN1, EYDFINN MAGNUSSEN2 and CHRISTOPHER R. TILLQUIST1.
The Faroe Islands are a small archipelago in the North Atlantic Ocean. With a current population of approximately 48,000 individuals and evidence of high levels of genetic drift, the Faroese are thought to have remained highly homogeneous since the islands were settled by Vikings around 900CE. Despite their geographic isolation, however, there is historical evidence that the Faroese experienced sporadic contact with other populations since the time of founding. Contact with Barbary pirates in the seventeenth century is documented in the Faroes; there is also the possibility of modern migrations to work in the highly productive fishery. This study set out to distinguish the signal of the original founders from later migrants. Eleven Y-chromosomal STR markers were scored for 139 Faroese males from three geographically dispersed islands. Haplotypes were analyzed using Athey's method to infer haplogroup. Median-joining networks within haplogroups were constructed to determine the phylogenetic relationships within the Faroese and between likely parental populations—Danish, Irish, and Norwegians. Dispersal patterns of individuals around Faroese haplogroups suggest different times of haplotype introduction to the islands. The most common haplogroup, R1a, consists of a large node with a tight network of neighbor haplotypes, such that 68% of individuals are one or two mutational steps away. This pattern may represent the early founder event of R1a in the Faroes. Other distributions, especially of non-Scandinavian haplotypes, document more recent introductions to the islands. The overall pattern is one of a strong founder effect followed by minor instances of later migrations.



Date estimates for major mitochondrial haplogroups in Yemen.
DEVEN N. VYAS1, VIKTOR ČERNÝ2, ALI AL-MEERI3 and CONNIE J. MULLIGAN1.
Yemen occupies a key location as the first stop for anatomically modern humans on a theoretical southern migration route out of Africa. If modern humans did pass through Yemen during the first migrations out of Africa and if they left modern-day descendants, we would expect to see deep divergences in the Yemeni mitochondrial gene tree. Alternatively, if modern humans passed through Yemen but did not leave modern-day descendants or if Yemen was not on the path of these ancient migrations, we would expect more recent dates to be associated with Yemeni mitochondrial haplogroups.
Using 44 previously sequenced mitochondrial genomes as well as 24 newly sequenced mitochondrial genomes from samples collected throughout Yemen, several methods were used to estimate divergence dates of major Yemeni haplogroups including L2, M, R0a and HV. Specifically, phylogenetic trees were generated using MrBayes and maximum likelihood methods. Bayesian and ρ statistic based methods were used to estimate dates of Yemeni haplogroups and these dates were compared with each other, previously published dates for these haplogroups, approximate dates of climatic change that might be expected to correlate with population expansions, and estimates based on archaeological and paleontological evidence for the first migrations out of Africa. These comparisons are intended to cover the range of possible haplogroup divergence dates with respect to the history of early modern humans in southern Arabia.


November 19, 2011

The "Upper Paleolithic" of South Arabia

I came across this interesting book chapter on The "Upper Paleolithic" of South Arabia by Jeffrey Rose and Vitaly Usik. I first became aware of Dr. Rose's work in Southern Arabia when I watched the "Incredible Human Journey" (see Related links below) a couple of years ago. The conclusions of the chapter seem to mesh quite well with some of my recent thoughts about a possible Out-of-Arabia expansion of modern humans, posterior to the earlier Out-of-Africa.

The following figure is instructive:

Notice the super-aridity of MIS 4, circa 70ka BP. This would certainly be an awful time for anyone to move into Arabia. Conversely, if there were anatomically modern people living there prior to MIS 4, the onset of the super-arid phase during MIS 4 would be a great time to get out.

As I mention in my previous post on mtDNA haplogroup L3, I think that the major human expansion associated with haplogroup L3 and its M/N subclades originated in Arabia, and the super-arid MIS 4 phase looks about right for a bottleneck out of which the descendants of only a single woman, the L3 ur-mother would survive.

From the book chapter:
So, we are able to make a few general observations regarding the Upper Paleolithic found in the southern portions of the peninsula: (1) there are multiple phases of human occupation in South Arabia throughout the latter half of the Upper Pleistocene, (2) there are elements loosely related to the Levantine sequence, however, the South Arabian Upper Paleolithic probably belongs to a unique and locally-derived lithic tradition, (3) there do not appear to be any links with East Africa (with the exception of the Hargeisan) from MIS 4-onward, and (4) assemblages from southern and south-western Arabia are dominated by different laminar-based technologies between 75 and 8 ka.
The Hargeisan is interesting, because it is a possible link of an expansion from Arabia to Africa:
One potentially additional piece of evidence for this hypothesized Near Eastern/Arabian-derived human expansion is the anomalous Hargeisan Industry found in the Horn of Africa. Known from a small number of findspots around Hargeisa (Clark, 1954), Boosasso (Graziosi, 1954) and Midhishi Cave in the Golis Mountains of northern Somalia (Gresham, 1984; Brandt, 1986), the Hargeisan has been found overlying MSA material and beneath LSA occupation layers.
Of course, the political situation in Somalia may suggest that scientists won't be studying the Hargeisan anytime soon.

More from the book chapter:
From an archaeological perspective, Straus and Bar-Yosef (2001: 2) entertain the same possibility: “there is, however, no reason a priori to exclude the possibility that intercontinental contacts occurred on a two-way street, especially at Suez, via Sinai, or across the shallow Bab al Mandab, so close to that corridor to sub-Saharan Africa, the Nile.” Marks (2005) and Otte et al. (2007) envisage similar scenarios during the MP/UP transitions in the Near East and Zagros regions. Both scholars argue that the archaeological evidence from Eastern Europe and Western Asia indicate the expansion of European UP technologies radiated from these areas, rather than Africa, during early MIS 3. Echoing this proposition from a biological perspective, Schillaci (2008) proposes the spread of Levantine-derived peoples into Australasia between 60 and 40 ka based on fossil evidence and phylogenetic relationships between populations.
and:
We maintain that the evidence from Arabia indicates the post-MIS 4 human expansion did not originate in sub-Saharan Africa; rather, early modern humans have emerged from a geographic range encompassing areas of northeast Africa, Western Asia, Arabia, and South Asia. These populations would have been forced to contract into environmentally stable refugia around Arabia such as the Ur-Schatt River Valley, coastal oases, Yemeni Highlands, and/or the Dhofar Mountains during climatic downturns. As such, the fluctuating dynamic between landscape carrying capacity and population density may have been a critical mechanism driving early human dispersals from the region. Episodes of climate change caused large portions of the Arabian peninsula to become uninhabitable due to such calamities as the inundation of the emerged continental shelf and desertification throughout the interior. Given the potential importance of these once favorable, now uninhabitable zones, future investigations in and around Arabia should endeavor to explore the heart of the desert and bottom of the sea.

Related:

September 08, 2010

ASHG 2010 abstracts

The 2010 meeting of the American Society of Human Genetics is in November. Here are some interesting abstracts that caught my eye:

It's nice to finally see a genomic study on the Greek population.
P. Paschou et al. Evaluation of the HapMap dataset as reference for the Greek population.
The HapMap project has provided a unique tool for the analysis of human genetic variation, providing reference information for allele frequency and genotype distributions as well as linkage disequilibrium patterns of Single Nucleotide Polymorphisms (SNPs) across the entire genome. The latest release of HapMap phase 3 data provides genotypes for millions of SNPs in 11 populations from around the world, with Europe being represented by the CEU (originating from Northwestern Europe) and the TSI populations (Tuscan Italians from Southern Europe). Although initial studies support the fact that the CEU can be used as reference for the selection of tagging SNPs in other European populations, a critical step in the design of genetic association studies, this hypothesis has not been extensively studied across Europe and in particular in Southern Europe. We set out to explore the extent to which the HapMap populations can be used as reference for a previously unstudied population of South-Eastern Europe, the Greek population. To do so we studied genomic variation in 1,813 SNPs, genotyped by our group in 56 individuals of Greek origin, and compared them to the CEU and TSI genotypes (1,813 SNPs from the CEU HapMap dataset and 1,205 from the TSI dataset). The studied SNPs are spread over 13 autosomal chromosomes and 26 regions, ranging in size from 120Kb to more than 4Mb. Genotype, allele frequency, and pairwise LD measures were compared across all three populations. PCA was used in order to identify those markers that are responsible for the observed inter-sample variance. Tagging SNPs were selected in the CEU and TSI samples and their transferability to the Greek population was tested, using both the r2 metric as well as the efficiency of genotype imputation of the non-selected SNPs. Our results demonstrate that, although the CEU population can to some extent be used as reference for the Greek population, it is preferable to use as reference a European population of closer genetic ancestry, like the TSI. These results are applicable in medical genetics, in order to inform the design of genetic association studies, as well as in studies of evolutionary relationships of Southern European populations.
One of the great problems of Eurasian anthropology is whether the Uralic populations are simply variable admixtures of Caucasoids and Mongoloids or they contain a tertium quid in the form of a Proto-Uralic element. The latter need not be distinct from the other two, as it can also be an old or stabilized blend of the two major Eurasian races that later admixed with more recent groups on either side. The abstract does not seem promising in this respect, i.e., in identifying a common core of ancestry among Uralic speakers in addition to their variable east-west admixture, but it would be nice to see if anything like that exists in the paper.

K. Tambets et al. Haploid and autosomal variation within a linguistic continuum of the Uralic-speaking people of Eurasia.
For about last two decades the examination of uniparentally inherited genetic marker systems revealing the variation embedded in mtDNA and Y chromosome has been the main tool in the studies of human genetic origins. Within few recent years the analysis of the genome-wide SNP data of individuals from different populations has started to give promising new insights in the field of human population genetics. The uniparentally inherited markers have shown slightly different demographic scenarios for the maternal and paternal lineages of North Eurasian, particularly of European Uralic-speaking populations. The geographical location of a population has evidently been the most important component that dictates the proportion of western and eastern mtDNA types in the gene pool of Uralic-speakers. Thus, the palette of maternal lineages of the Uralic-speakers resembles that of their geographically close European or Western Siberian Indo-European and/or Altaic-speaking neighbours, respectively. At the same time, the most frequent North Eurasian Y chromosome type N1c, that is also a common link between almost all Uralic-speakers, is with few exceptions rare, if present at all, among Indo-European-speakers of Western and Southern Europe. Here we combine genome-wide high density SNP data (650 000 SNPs, Illumina) with uniparentally inherited mtDNA and Y-chromosome variation of 16 Uralic-speaking populations to assess their place on the genetic landscape of North Eurasia. By the use of principal component and structure-like analysis on the autosomal data we show that the proportions of western and eastern ancestry components among the Uralic-speakers are determined mostly by geographical factors. The westernmost populations from Europe, both Uralic- and Indo-European speakers, are similar in their pattern of ancestry components and show low levels (less than 10%) of the eastern component. Conversely, the eastern ancestry component is dominant (60-70%) in the gene pool of the Siberian Uralic-speakers. In general, the genome-wide analyses corroborate the results of mtDNA analysis and do not reflect the common genetic characteristics between western and eastern Uralic-speakers at the level seen in case of N1c. Interestingly, among Saami from North Europe, who are often considered as „outliers“ in genetic studies, the dominant western component is accompanied by 30% of eastern component making them more similar to Volga-Uralic populations than to their closest neighbours.



This seems to validate my thoughts on relics and their importance in age estimation.

U. A. Perego et al. The Initial Peopling Of The Americas: An Ever-Growing Number Of Founding Mitochondrial Genomes From Beringia
Genetic evidence based on mitochondrial DNA (mtDNA) has recently revealed the existence of additional founding lineages that have contributed to the first peopling of America’s double-continent in addition to the more popular five Native American haplogroups (A2, B2, C1, D1 and X2a), and has demonstrated as well the need for additional sampling and analysis to be performed for some of the already known but poorly characterized lineages. One paradigmatic example is represented by the pan-American haplogroup C1. Two of its sub-branches (C1b and C1c) harbor ages and geographical distributions that are indicative of an early arrival from Beringia about 15-17,000 years ago, concomitantly with the other currently accepted Paleo-Indian founders. However, the estimated age of C1d - the third Native American subset of C1 - is only 8-10,000 years, which is suggestive of a much later entry and spread in the Americas. In this study, we shed light on the origin of this enigmatic Native American branch of C1 by completely sequencing a large number of C1d mitochondrial genomes from a wide range of geographically diverse, mixed and indigenous American populations. The revised phylogeny shows that the age previously reported for C1d was heavily underestimated and indicate that C1d is ancient enough to be among the founding Paleo-Indian mtDNA lineages. Moreover, our results reveal that there were two C1d founder genomes for Paleo-Indians that most likely arose early (~16kya), either in the dynamic Beringian gene pool, or at a very initial stage of the Paleo-Indian southward migration. This brings the recognized maternal founding lineages of Native Americans to the unexpected number of 15, and indicates that the overall number of Beringian or Asian founder mitochondrial genomes will probably continue to increase as more Native American haplogroups reach the same level of phylogenetic resolution as we obtained here for C1d. Additionally, we have confirmed a nearly identical geographic distribution pattern for haplogroup C1d when comparing samples collected in the general mixed population with those from native tribal groups, as it was also reported previously for haplogroups X2a and D4h3. This substantiates the validity of searching large public mtDNA databases (such as the one available through the Sorenson Molecular Genealogy Foundation, www.SMGF.org) for novel founder candidates able to reveal unknown details concerning the ancient human history of the Americas.

Another interesting abstract. I've written before about the association of Y-chromosome haplogroups with the spread of Semitic speakers and the agreement with language phylogenetics.

N. Al-Zahery et al. The male gene pool of the contemporary Mesopotamia marsh population supports their Semitic origin.
The origin of the modern Mesopotamia marsh people, which are locally called “Ma’dan” or “Marsh’s Arabs”, is a question of great interest. Based on their life-style (living in reed houses, grazing of water buffalo and other aspects) and local archaeological sites, many historians and archaeologists believe they may have Sumerian ancestry. Although little is known about the origin of Sumerians themselves, two main hypotheses have been advanced in this regard. According to the first, Sumerians were a group of populations which migrated from the “South East” following a seashore route through the Arabian Gulf, and settled down in the southern marshes of Iraq. According to the second, the advancement of the Sumerian civilization is the result of migration from the mountainous area of Anatolia to the southern marshes of Iraq where they settled, adsorbing previous populations. In order to shed some light on the genetic origin of the Mesopotamia marsh population, we investigated the male gene pool of 145 DNA samples of modern Mesopotamia people, still living in marshes in the south of Iraq. The analyses of Single Nucleotide Polymorphisms (SNPs) and Short Tandem Repeats (STRs) of the paternally transmitted Male Specific region of the Y chromosome (MSY) revealed that more than 80% of marsh Y chromosomes belong to (Hg) J1-M267, the autochthonous haplogroup of Middle Eastern/Semitic speakers with possible recent expansion and/or founder effect reflected by the reduced STRs variability. In particular, 90% of them were assigned to the J1e-M267-PAGE08 sub-haplogroup, which is the predominant Y chromosome lineage among Middle Eastern Arab populations (Yemen, Qatar, UAE, and Levant). Thus, these findings testify, at least from the paternal side, a strong Semitic Arabian component in the contemporary Mesopotamia marshes population, whereas no clear Anatolian and/or South Asian genetic evidence has been detected.
The finding of haplogroup I in China is surprising, as I is not generally found that far away from Europe. It would be interesting to see what the actual haplotypes are.
Y. Lu et al. Western Eurasian Y chromosomes found in the Chinese Salar ethnic group
Salar is a small Western-Turkish-speaking population living mostly in Qinghai province of China. The most similar languages to Salar are all far in Turkmenistan. Historical records suggested that they may be descendants of the Turkic nomadic tribes in Central Asia. In this study, 141 Salar Y chromosomes were analyzed for 39 SNP and 14 STR markers to investigate the potential imprints of their western ancestors. The most frequent haplogroup (hg) in this population sample is Hg R, comprising 40% of all Y chromosomes. Most of these Hg R samples belong to R1a1 (M17), which distributes in a wide geographic region including South Asia, East Europe, Central Asia, and South Siberia. Other four Western Eurasian haplogroups (G-2%, H-5%, I-3%, J-3%) were also found in Salar Y chromosome gene pool. These paternal lineages of Salar are absent in their East Asian neighbors but frequent in Central Asia. Y-STR-based analyses also grouped Salar to Central Asians. On the other side, Salar also has low frequencies of the East Asian specific Hg D and Hg O, suggesting possible gene flow from their neighboring populations. This Y chromosome study demonstrated that Salar well keeps the Western Eurasian paternal lineages of their Central Asian ancestors although they may have migrated to Central China for about 800 years.

I wish that more "people pairs" would be studied this way, as it would give us some good insight of how migration affects gene pools (allele frequency changes, founder effects, possible social selection etc.)

M. Davis et al. Ancient and recent demographic events influence mitochondrial DNA diversity in an immigrant Basque population
The Basques are an ancient people, considered by many anthropologists to represent the oldest extant European population. Because of this, they have been the subject of numerous sociological and biological investigations. The Basque Diaspora, a relatively recent demographic expansion of the Basque population, has until now been overlooked in genetic studies. Samples were taken from 53 individuals with Basque ancestry in Boise, Idaho, and the mitochondrial DNA (mtDNA) sequence variation of the first and second hypervariable regions were determined. Thirty-six mtDNA haplotypes were detected in the sample. Comparing the genetic diversity in the Idaho sample with other Basque populations, signatures of founder effects were observed, consistent with both the recent and ancient history of Basque mitochondrial lineages. There has been a marked alteration of haplogroup frequency and diversity, and there is a slight reduction in other measures of diversity in the NW Basque population compared to the native Basque population. We have found a relatively high percentage of the Cambridge Reference Sequence (rCRS) haplotype for hypervariable regions I and II, which is absent in previous studies of Basque mtDNA, and rare in other Spanish populations. The amount of nucleotide diversity is consistent with a sample that is predominantly haplogroup H, which is especially common in the Basque regions of Europe, due to ancient migrations and expansions out of glacial refugia. This is the first report of mtDNA diversity in an immigrant Basque population, and we find that the diversity in NW Basques can be explained by the recent history of migration, as well as the phylogeography and diversity of the major European haplogroups.


W. S. Watkins et al. Admixture in New World populations: an analysis of Y-chromosome, mtDNA, and genome-wide microarray data
The first major interaction between Native Americans and Europeans is documented historically and occurred less than 550 years ago. This recent time frame provides an excellent opportunity to investigate the effects of admixture between two populations that were previously separated for hundreds of generations. To characterize European admixture in Native American populations, we sampled and analyzed a group of isolated Totonac agriculturists from tropical Mexico near Veracruz and a group of native Bolivians predominantly from the mountainous region near La Paz, Boliva. Mitochondrial sequencing of HVS1 showed that all samples had pre-Columbian mtDNA haplogroups (A, B, C, and D). Using a panel of 48 STRs or 12 Y-chromosome SNPs, Totonac Y-chromosomes lineages were all assigned to the pre-Columbian haplogroup Q1a3a, and Bolivian Y-chromosome lineages were assigned to haplogroups Q1a3a, R1, and J2. Haplogroups R1 and J2 are common in European populations. Principal components analysis (PCA) using >800K autosomal SNPs typed in 24 Totonacs and 23 Bolivians showed that all Totonacs and 14 Bolivians clustered distinctly from Eurasian individuals. Nine Bolivians, however, were positioned between the New World and European PCA clusters. Admixture analysis showed that these nine samples had 21 - 33% European admixture using a European reference population. All three observed Y-chromosome haplogroups, including the well-studied pre-Columbian haplogroup Q1a3a, occurred in the admixed individuals. Two of the nine admixed individuals had pre-Columbian mtDNA and Y-chromosome haplogroups but 21-23% European ancestry. This result demonstrates that Y-chromosome and mtDNA haplogroups are only partial indicators of an individual’s complete ancestry.

Readers of the blog know that I don't agree with the scenario presented in the followin abstract. The serial founder effect idea is used by geneticists to explain the overall reduced genetic diversity of our species (that we appear to be young, in evolutionary terms). Personally, I don't see how a smart, expanding species that all of the sudden had access to the resources of the landmass of Eurasia went through these extreme bottlenecks.
I think that the alternative of a larger human population, genetic diversity reduced across the species by ongoing climate- and culture-mediated selection, and admixture within Africa itself -where a particular expanding H. sapiens group must've co-existed with pre-existed hominids, anatomically modern or not- has merit.
J. Long et al. Evidence for archaic admixture in contemporary non-African human populations
Analyses of large-scale genetic data sets show evidence for a series of founder effects that occurred as modern humans left Africa and settled the rest of the world. Nonetheless, research on modern humans has not ruled out the possibility that other processes, such as local gene flow, or mixing between archaic and modern humans, have also contributed to modern human diversity. Recent analyses of the Neanderthal genome make archaic admixture a salient issue because they show evidence for mixing between Neanderthals and out-of-Africa migrants. The present study examines evidence for archaic admixture in genotypes for 619 microsatellite loci collected from over 2,000 individuals from 100 human populations. We obtained these data from the Marshfield Clinic collection. The populations analyzed represent all inhabited continents of the world. In our analysis, we formulate the serial founder effects (SFE) model as a special case of a phylogenetic model promoted by Cavalli-Sforza and his associates. In this light, the SFE process makes four predictions: 1) A tree of descent according to the pattern of fissions. 2) The root of the tree lies in Africa. 3) The length of each branch is proportional to ratio of evolutionary time to effective population size. 4) The gene identity between all pairs of populations that share the same most recent common ancestor is equal in expectation. Using hypothesis tests based on generalized hierarchical statistical models, we find good agreement between the SFE predictions and diversity within and between African populations, and we find good agreement between the SFE predictions and diversity between non-African populations. However, there is more diversity within the non-African populations than the SRE model can account for. This makes for greater genetic distance between Africans and non-Africans than otherwise expected. How and where did the non-Africans obtain this diversity? A simple explanation for the finding is that the earliest migrants out-of-Africa mixed with an archaic population such as Neanderthals prior to their expansion throughout Europe and Asia. Coalescent based computer simulations of the SFE model with mixing support our interpretation. The time and place that we detect mixing coincides perfectly with that detected in a recent examination of Neanderthal genome sequences. Our study shows that genomic diversity in modern humans still reflects ancient events and processes.

C. Flores et al. Using EuroAIMs to measure admixture proportions in atypical European populations: the case of Canary Islanders
Using ancestry informative markers (AIMs) allows reducing the number of makers needed for population stratification adjustments in association studies. As few as 100 AIMs are sufficient to adjust for the largest European axis of differentiation (i.e. EuroAIMs). However, their use for ancestry inference and adjustment in association studies in atypical European populations such as the Canary Islanders, a recently African-admixed population from Spain, needs to be addressed. We aimed to explore whether EuroAIMs were suitable both for the inference of Spanish and Northwest African admixture proportions and for ancestry adjustments in association studies including samples from Canary Islanders. We analyzed samples from Canary Islanders, mainland Spanish (IBE) and Northwest Africans (NWA) for 93 EuroAIMs and compared the data with CEU and YRI from HapMap, Basques and Mozabite from HGDP, as well as from previously analyzed European samples. The major genetic difference was observed between NWA and all European populations, preserving the northwest-to-southeast differentiation of European populations in the second axis. Analyses revealed that Canary Islanders were intermediate between IBE and NWA, and that direct sub-Saharan African influences were negligible. Assessment of individual admixtures without prior population information clearly identified two subpopulations corresponding to NWA and IBE, while Canary Islanders were admixed with an average of 17.4% Northwest African contribution varying largely among individuals (range 0-95.7%). As few as 23 EuroAIMs correctly estimated population membership to IBE and NWA, while 69 EuroAIMs were required to accurately estimate individual admixture proportions in Canary Islanders. Ancestry estimates based on a subset of 69 EuroAIMs also controlled significant allele frequency differences between IBE and Canary Islanders. These data suggest that a handful of EuroAIMs would be useful to control false-positives in association studies performed in Spanish populations. Supported by FUNCIS 23/07 and grants from the Spanish Ministry of Science and Innovation PI081383 and EMER07/001 to CF.
As I have I mentioned before, the Maasai (and many other east Africans in various degrees) are intermediate between Negroids and Caucasoids, and hence admixture estimates considering Yoruba Nigerians would tend to underestimate the African element. It's important to remember that extant Africans are not uniform, ranging from Caucasoids to Negroids, Pygmies, and Khoi-San, with multiple identifiable clusters within the major Negroid group itself, and all sorts of between-group gene flow in a regional basis. It is always useful (as is the case e.g., with African Americans) to both use historical knowledge about population sources, and also to validate historical narratives with the genetic evidence.
R. L. Raaum et al. Autosomal African admixture in Yemeni populations.
Approximately 30% of mtDNA lineages in South Arabian samples are African L haplotypes, whose origin has usually been attributed to migration and assimilation of African females into the Arabian population over approximately the last 2,500 years. Few In contrast, few Y chromosome lineages of clear recent sub-Saharan African origin have been found in Southern Arabian populations. This bias in maternal and paternal lineages is in accord with historical accounts of the female bias in the Middle Eastern slave trade. In order to evaluate autosomal African ancestry, we collected high-resolution SNP genotype data from a geographically representative set of 62 Yemenis selected from a collection of 552 samples acquired in the Spring of 2007. The ancestry of chromosomal segments in the Yemeni population was estimated using a haplotype-based local ancestry estimation method, HAPMIX. The HAPMIX method is based on a two way admixture model that requires two phased reference populations; we used the HapMap Yoruba in Ibadan, Nigeria (YRI), Luhya in Webuye, Kenya (LWK), Maasai in Kinyawa, Kenya (MKK), and CEPH US residents with ancestry from northern and western Europe (CEU) samples. The three African reference populations include two Bantu-speaking groups (YRI and LWK) and one Nilotic-speaking group (MKK). We estimated local ancestry in the Yemeni sample with all three European-African reference population combinations (CEU-YRI, CEU-LWK, CEU-MKK). The correlations among African ancestry calculated using all three reference population combinations are high (r > 0.98 in all pairwise correlations). Furthermore, there is no significant difference between the average proportion of African ancestry in Yemenis calculated using either of the two Bantu-speaking reference populations: CEU-YRI (mean 0.062, sd 0.044) and CEU-LWK (mean 0.076, sd 0.049) (p=0.13, two-tailed Welch two sample t-test). However, the average African ancestry calculated using the Maasai reference population (CEU-MKK, mean 0.148, sd 0.060) is significantly greater from that calculated using either the Yoruba or Luhya reference populations (p less than 0.0001 in both comparison, two-tailed Welch two sample t-test). These data suggest that the source population for the African ancestry of the Yemeni population is more similar to the contemporary Maasai population than either the Luhya or Yoruba.
The next abstract seems fun; it's always nice to see something that isn't like everything that came before it.
T. Rzeszutek et al. Music as a novel marker in the study of prehistoric human migrations.
The study of prehistoric human population history is often fraught with controversy owing to incongruent evidence among various markers of present-day genetic and cultural diversity. While archaeological evidence can be used to calibrate the conclusions drawn from present-day diversity, the fickle nature of the fossil record leaves some migration histories unresolved. Our work analyzes the potential of music - in particular, vocal music - to serve as novel migration marker, bolstering established migration work and shedding light on regions of the world whose settlement history is contested. One such migration is the recent expansion of Austronesian-speaking peoples across the Pacific within the last 6000 years. The dominant hypothesis posits a recent origin in Taiwan, with a rapid movement southwards and eastwards to populate Polynesia during the following 3500 years. While this model is strongly supported by both archaeological evidence and the present-day distribution of linguistic diversity, our goal was to analyze whether music could serve as a novel line of evidence in the study of Pacific prehistory. A critical concern regarding any migration marker is its time depth. In order to examine this for music, we analyzed correlations between musical diversity and mitochondrial-DNA diversity in 9 Taiwanese aboriginal tribes for which both types of data were available. A sample of 226 choral songs was analyzed using 39 binary characters representing significant structural features of music (e.g., rhythm, interval size, melodic contour, etc.). The musical samples were restricted to ritual musics, which constitute the most conservative (i.e., slowly changing) component of a culture’s repertoire. Mantel tests showed a significant correlation between musical distance and genetic distance among these 9 tribes, suggesting that music may have a time depth comparable to widely-used genetic markers like mitochondrial DNA. This work demonstrates that music has the potential to enrich the conclusions drawn from other markers, and establishes methods for employing it as a tool in the study of prehistoric human movements throughout the world. At the same time, we want to capitalize on music’s own unique dynamics of change over time and place, particularly its capacity for admixture. In other words, music might not only be able to support the narratives told by other migration markers but shed new light on the histories of population movement and cultural contact.


The bolded part in the following abstract makes sense, as it indicates (i) the distinctiveness of Ashkenazi Jews compared to CEU Europeans, and (ii) the fairly recent widespread formation of admixed individuals (in the last couple of generations) which generated individuals that are 1/4 1/2 and 3/4 AJ genomically.

V. Vacic et al., Admixture in Ashkenazi Jewish cohorts and implications for association studies.
Studies of complex genetic disorders may benefit from focusing on population isolates, such as Ashkenazi Jews (AJ). However, in order to truly exploit the advantages of reduced genetic diversity the self-declared AJ ancestry of study participants should be independently confirmed with available genetic data. We investigate whether the AJ cohorts display genetic heterogeneity, such as e.g. different rate of admixing in cases and controls, which could potentially confound disease association studies. We applied principal component analysis (PCA) to AJ cohorts ascertained in Israel and the US East Coast with the goal of characterizing population structure. As described previously, when compared to the HapMap samples with CEU, YRI and CHB/JPT ancestry, virtually all AJ samples cluster with the CEU. Similar analysis done on CEU and Jewish HapMap samples from Ashkenazi, Sephardic and Middle Eastern Jewish communities revealed that 97.8% of AJ samples cluster along the AJ-CEU axis, with modes at AJ and CEU cluster centers and at approximately quartile distances between them. We postulate that these groups correspond to 100-0, 75-25, 50-50, 25-75, and 0-100% AJ-CEU admixtures. Notably, only 91.7% of self-reported AJ individuals fall into the reference JHapMap panel AJ cluster, with 1.6, 3.3, 0.5 and 0.7% in the admixed modes ordered by decreasing fraction of AJ ancestry. We also observe admixing with the non-AJ Jewish communities: 0.7% of samples fall within the non-AJ clusters and 1.4% at a subgroup approximately halfway between the AJ and non-AJ cluster centers. In our dataset we found that when compared to the sample as a whole or only to controls, individuals with Crohn’s disease (CD) show significantly more admixing: 78.1, 3.1, 8.5, 2.0 and 0.9% in the 100, 75, 50, 25 and 0% AJ subgroups respectively. Also, CD samples show more admixing with non-AJ groups (2.8 and 1.0% in the 50-50 and 0-100 AJ-non-AJ subgroups). Isolates typically exhibit a greater amount of cryptic relatedness compared to outbred populations, which motivates an orthogonal method for verifying AJ ancestry based on identity-by-descent (IBD). The high background level of IBD within the Ashkenazi Jewish community can be used to estimate degree of AJ ancestry by averaging the IBD between a sample under study and the AJ individuals in the JHapMap panel. Our preliminary results show that this method recapitulates the high-level results from the PCA analysis and provides better resolution.

July 14, 2010

mtDNA of Yemeni and Ethiopian Jews

From the paper:
Mitochondrial DNA analysis also revealed a high diversity of sub-Saharan African and Eurasian haplotypes in both the Yemenite and Ethiopian Jewish populations (see Fig. 2). Specifically, common haplotypes (haplotypes present at [5%) in Yemenite Jews include the African haplogroup L3x1 and Eurasian haplogroups R0a (renamed from (preHV)1 (Torroni et al., 2006), HV1, J2a1a [renamed from J1b (Palanichamy et al., 2004)] K, R2, U, and U1, and in Ethiopian Jews include African haplogroups L2a1b2 and L5a1 and Eurasian haplogroups R0a and M1a1 (see Fig. 2). Overall, sub-
Saharan African L haplotypes [hereafter referred to as L(xM,N), i.e., all African haplotypes except M and N, following the nomenclature of Behar et al. (2008)], comprise a large proportion of the genetic variation in both Jewish populations, representing 20% in the Yemenite Jews and 50% in Ethiopian Jews. This high frequency contrasts with other Jewish populations, such as Near Eastern and Ashkenazi Jews, who almost entirely lack L(xM,N) haplogroups (Thomas et al., 2002; Richards et al., 2003).
I think that the authors' conclusion that Yemenite Jews are partially descended from Israeli exiles is premature. Sure, they can exclude large-scale introgression of Yemeni mtDNA, but the universe of possibilities is not limited to either Israeli or Yemenite.

The way I see it, only a large-scale study of all global Jewish populations may uncover verified ancient Jewish lineages for both Y-chromosomes and mtDNA. The recent studies on Jews have uncovered several genetic sub-clusters of Jews, and only lineages that occur in 2 or more of these clusters, and preferably geographically separated ones have a strong claim of representing original Jewish lineages. There is a limit on what can be uncovered about the past from the study of living populations.

American Journal of Physical Anthropology doi: 10.1002/ajpa.21360

Mitochondrial DNA reveals distinct evolutionary histories for Jewish populations in Yemen and Ethiopia

Amy L. Non et al.

Abstract

Southern Arabia and the Horn of Africa are important geographic centers for the study of human population history because a great deal of migration has characterized these regions since the first emergence of humans out of Africa. Analysis of Jewish groups provides a unique opportunity to investigate more recent population histories in this area. Mitochondrial DNA is used to investigate the maternal evolutionary history and can be combined with historical and linguistic data to test various population histories. In this study, we assay mitochondrial control region DNA sequence and diagnostic coding variants in Yemenite (n = 45) and Ethiopian (n = 41) Jewish populations, as well as in neighboring non-Jewish Yemeni (n = 50) and Ethiopian (previously published Semitic speakers) populations. We investigate their population histories through a comparison of haplogroup distributions and phylogenetic networks. A high frequency of sub-Saharan African L haplogroups was found in both Jewish populations, indicating a significant African maternal contribution unlike other Jewish Diaspora populations. However, no identical haplotypes were shared between the Yemenite and Ethiopian Jewish populations, suggesting very little gene flow between the populations and potentially distinct maternal population histories. These new data are also used to investigate alternate population histories in the context of historical and linguistic data. Specifically, Yemenite Jewish mitochondrial diversity reflects potential descent from ancient Israeli exiles and shared African and Middle Eastern ancestry with little evidence for large-scale conversion of local Yemeni. In contrast, the Ethiopian Jewish population appears to be a subset of the larger Ethiopian population suggesting descent primarily through conversion of local women.

Link

May 23, 2009

Y chromosome population structure in Arabian peninsula

On the left, the MDS plot of genetic distances in studied populations and others from the literature. The haplotypes are available in free supplementary material (pdf). Someone ought to feed these to Whit Athey's haplogroup predictor to get estimates of the haplogroup composition of the Arabian populations.

Hum Hered 2009;68:45-54 (DOI: 10.1159/000210448)

Local Population Structure in Arabian Peninsula Revealed by Y-STR Diversity

Farida Alshamali et al.

Abstract

Genetic studies have been underway on Arabian Peninsula populations because of their pivotal geographic location for population migration and times of occurrence. To assist in better understanding population dynamics in this region, evidence is presented herein on local population structure in the Arabian Peninsula, based on Y-STR characterisation in four Arabian samples and its comparison in a broad geographical scale. Our results demonstrate that geography played an important role in shaping the genetic structure of the region around the Near-East. Populations are grouped regionally but none of these groups is significantly differentiated from others and all groups merge in the Near-East, in keeping with this important migration corridor for the human species. Focusing on the Arabian Peninsula, we show that Dubai and Oman share genetic affinities with other Near-Eastern populations, while Saudi Arabia and Yemen show a relative distinctive isolated background. Those two populations may have been kept relatively separated from migration routes, maybe due to their location in a desert area.

Link

February 15, 2008

News on Arabian mtDNA

Not one but two recent paper on Arabian mtDNA, giving us a better idea of its geographical structure. I am not sure what to make of the assertion in the first paper that the Arabian peninsula has been the recipient of genetic input from Australia; well, it's in an open access journal so you can form your own opinions.

BMC Evol Biol. 2008 Feb 12;8(1):45 [Epub ahead of print]

Mitochondrial DNA structure in the Arabian Peninsula.

Abu-Amero KK, Larruga JM, Cabrera VM, Gonzalez AM.

ABSTRACT: BACKGROUND: Two potential migratory routes followed by modern humans to colonize Eurasia from Africa have been proposed. These are the two natural passageways that connect both continents: the northern route through the Sinai Peninsula and the southern route across the Bab al Mandab strait. Recent archaeological and genetic evidence have favored a unique southern coastal route. Under this scenario, the study of the population genetic structure of the Arabian Peninsula, the first step out of Africa, to search for primary genetic links between Africa and Eurasia, is crucial. The haploid and maternally inherited mitochondrial DNA (mtDNA) molecule has been the most used genetic marker to identify and to relate lineages with clear geographic origins, as the African Ls and the Eurasian M and N that have a common root with the Africans L3. RESULTS: To assess the role of the Arabian Peninsula in the southern route, we genetically analyzed 553 Saudi Arabs using partial (546) and complete mtDNA (7) sequencing, and compared the lineages obtained with those present in Africa, the Near East, central, east and southeast Asia and Australasia. The results showed that the Arabian Peninsula has received substantial gene flow from Africa (20%), detected by the presence of L, M1 and U6 lineages; that an 18% of the Arabian Peninsula lineages have a clear eastern provenance, mainly represented by U lineages; but also by Indian M lineages and rare M links with Central Asia, Indonesia and even Australia. However, the bulk (62%) of the Arabian lineages has a Northern source. CONCLUSIONS: Although there is evidence of Neolithic and more recent expansions in the Arabian Peninsula, mainly detected by (preHV)1 and J1b lineages, the lack of primitive autochthonous M and N sequences, suggests that this area has been more a receptor of human migrations, including historic ones, from Africa, India, Indonesia and even Australia, than a demographic expansion center along the proposed southern coastal route.

Link

Am J Phys Anthropol. 2008 Feb 6 [Epub ahead of print]

Regional differences in the distribution of the sub-Saharan, West Eurasian, and South Asian mtDNA lineages in Yemen.

Cerný V et al.

Despite its key location for population movements out of and back into Africa, Yemen has not yet been sampled on a regional level for an investigation of sub-Saharan, West Eurasian, and South Asian genetic contributions. In this study, we present mitochondrial DNA (mtDNA) data for regionally distinct Yemeni populations that reveal different distributions of mtDNA lineages. An extensive database of mtDNA sequences from North and East African, Middle Eastern and Indian populations was analyzed to provide a context for the regional Yemeni mtDNA datasets. The groups of western Yemen appear to be most closely related to Middle Eastern and North African populations, while the eastern Yemeni population from Hadramawt is most closely related to East Africa. Furthermore, haplotype matches with Africa are almost exclusively confined to West Eurasian R0a haplogroup in southwestern Yemen, although more sub-Saharan L-type matches appear in more northern Yemeni populations. In fact, Yemeni populations have the highest frequency of R0a haplotypes detected to date, thus Yemen or southern Arabia may be the site of the initial expansion of this haplogroup. Whereas two variants of the sub-Saharan haplogroup M1 were detected only in southwestern Yemen close to the Bab el-Mandeb Strait, different non-African M haplotypes were detected at low frequencies ( approximately 2%) in western parts of the country and at a higher frequency (7.5%) in the Hadramawt. We conclude that the Yemeni gene pool is highly stratified both regionally and temporally and that it has received West Eurasian, Northeast African, and South Asian gene flow.

Link