Y chromosomes and mtDNA from the Maldives

 

Of interest from the paper:

The haplogroup J(M304) Y chromosomes are all in subgroup J2(M172).

...

However, Eaaswarkhanth et al. (2010) report that Muslims and non-Muslims in India largely have the same Y-haplogroup frequency distribution, except that in Muslims low frequencies of Y-E1b1b1a(M78), Y-J(M304)(xJ2(M172)), and Y-G(M201) are found that are absent in non-Muslims (Eaaswarkhanth et al., 2010). In our Maldivian sample, none of those Y-haplogroups were found.

AJPA DOI: 10.1002/ajpa.22256
Indian ocean crossroads: Human genetic origin and population structure in the maldives
Jeroen Pijpe et al.
The Maldives are an 850 km-long string of atolls located centrally in the northern Indian Ocean basin. Because of this geographic situation, the present-day Maldivian population has potential for uncovering genetic signatures of historic migration events in the region. We therefore studied autosomal DNA-, mitochondrial DNA-, and Y-chromosomal DNA markers in a representative sample of 141 unrelated Maldivians, with 119 from six major settlements. We found a total of 63 different mtDNA haplotypes that could be allocated to 29 mtDNA haplogroups, mostly within the M, R, and U clades. We found 66 different Y-STR haplotypes in 10 Y-chromosome haplogroups, predominantly H1, J2, L, R1a1a, and R2. Parental admixture analysis for mtDNA- and Y-haplogroup data indicates a strong genetic link between the Maldive Islands and mainland South Asia, and excludes significant gene flow from Southeast Asia. Paternal admixture from West Asia is detected, but cannot be distinguished from admixture from South Asia. Maternal admixture from West Asia is excluded. Within the Maldives, we find a subtle genetic substructure in all marker systems that is not directly related to geographic distance or linguistic dialect. We found reduced Y-STR diversity and reduced male-mediated gene flow between atolls, suggesting independent male founder effects for each atoll. Detected reduced female-mediated gene flow between atolls confirms a Maldives-specific history of matrilocality. In conclusion, our new genetic data agree with the commonly reported Maldivian ancestry in South Asia, but furthermore suggest multiple, independent immigration events and asymmetrical migration of females and males across the archipelago. Am J Phys Anthropol 000:000–000, 2013. © 2013 Wiley Periodicals, Inc.

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Y chromosomes of Bulgarians (Karachanak et al. 2013)

Bulgaria had been something of a blank area in studies of uniparental markers, so it's nice to finally see a comprehensive Y-chromosome study of the country.
The dates in the paper are based on the "evolutionary mutation rate". I suspect that ancient DNA will be the final arbiter in this issue, because, for example, a Mesolithic TMRCA of E-V13 in Bulgaria implies that we'll find a lot of it in Neolithic contexts, whereas a Bronze Age one implies that we'll find a little if any of it, and a discontinuity across time.
Of interest is the occurrence of some E*(xM35, M2) in this sample in Burgas, Varna, and Plovdiv. It would be interesting to trace the ancestry of the bearers of these Y-chromosomes. I know that there still exists a minority-within-a-minority of Black Muslims in Greek Thrace, and it's not inconceivable that these Y-chromosomes may represent the legacy of a similar population; in any case, their haplotypes can be found in Table S5 for anyone wanting to investigate.
SNP Diversity within R seems substantial, and as always, it is difficult to say much, since this may be a consequence of either (i) a plausible role of the Balkans as a staging point of the likely invasion of Europe in late prehistory, or (ii) back-migration of derived R-bearers into the Balkans, be them Slavs or Goths or "eastern" folks of various stripes during history. Once again, I suspect that ancient DNA might solve this riddle, or, alternatively, routine high-coverage sequencing of the Y chromosome that might inform us, e.g., about the TMRCA of a Bulgarian and a German R-U152 or a Bulgarian and Polish R-M458.
PLoS ONE 8(3): e56779. doi:10.1371/journal.pone.0056779
Y-Chromosome Diversity in Modern Bulgarians: New Clues about Their Ancestry
Sena Karachanak et al

To better define the structure and origin of the Bulgarian paternal gene pool, we have examined the Y-chromosome variation in 808 Bulgarian males. The analysis was performed by high-resolution genotyping of biallelic markers and by analyzing the STR variation within the most informative haplogroups. We found that the Y-chromosome gene pool in modern Bulgarians is primarily represented by Western Eurasian haplogroups with ~ 40% belonging to haplogroups E-V13 and I-M423, and 20% to R-M17. Haplogroups common in the Middle East (J and G) and in South Western Asia (R-L23*) occur at frequencies of 19% and 5%, respectively. Haplogroups C, N and Q, distinctive for Altaic and Central Asian Turkic-speaking populations, occur at the negligible frequency of only 1.5%. Principal Component analyses group Bulgarians with European populations, apart from Central Asian Turkic-speaking groups and South Western Asia populations. Within the country, the genetic variation is structured in Western, Central and Eastern Bulgaria indicating that the Balkan Mountains have been permeable to human movements. The lineage analysis provided the following interesting results: (i) R-L23* is present in Eastern Bulgaria since the post glacial period; (ii) haplogroup E-V13 has a Mesolithic age in Bulgaria from where it expanded after the arrival of farming; (iii) haplogroup J-M241 probably reflects the Neolithic westward expansion of farmers from the earliest sites along the Black Sea. On the whole, in light of the most recent historical studies, which indicate a substantial proto-Bulgarian input to the contemporary Bulgarian people, our data suggest that a common paternal ancestry between the proto-Bulgarians and the Altaic and Central Asian Turkic-speaking populations either did not exist or was negligible.
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Y chromosome and mtDNA study of modern Middle Eastern populations (Badro et al. 2013)

Y chromosome and mtDNA study of modern Middle Eastern populations (Badro et al. 2013)

I will just briefly comment on the occurrence of L3* mtDNA in the Near East. This is a critical haplogroup because of its age of ~70ky. If all L3* in the Near East represents African migrants, then only the M and N macrogroups appeared in Eurasia, and a good case can be made for a "late" OoA event.

On the other hand, it is quite possible that some of the L3* in the Near East does not represent recent admixture, but rather native forms of L3 with deep ancestry in the region. If that is the case, then the Near East will emerge as the origin of L3, with M, N representing Out-of-Near East-into-Eurasia founders, and the various L3*(xM, N) representing Out-of-Near East-into-Africa founders.

It is difficult to say at present what will turn out to be the case. Ancient DNA has the potential of resolving this issue, because if L3*(xM, N) in Eurasia is really recent (e.g., associated with Islamic/Arab dispersals spanning Africa and Eurasia), then it ought to be missing from the earliest genetic layers.

Also of interest the geographical distribution of Y-haplogroups; nothing much new here, but still useful as a reference:

PLoS ONE 8(1): e54616. doi:10.1371/journal.pone.0054616

Y-Chromosome and mtDNA Genetics Reveal Significant Contrasts in Affinities of Modern Middle Eastern Populations with European and African Populations 

Danielle A. Badro et al.

The Middle East was a funnel of human expansion out of Africa, a staging area for the Neolithic Agricultural Revolution, and the home to some of the earliest world empires. Post LGM expansions into the region and subsequent population movements created a striking genetic mosaic with distinct sex-based genetic differentiation. While prior studies have examined the mtDNA and Y-chromosome contrast in focal populations in the Middle East, none have undertaken a broad-spectrum survey including North and sub-Saharan Africa, Europe, and Middle Eastern populations. In this study 5,174 mtDNA and 4,658 Y-chromosome samples were investigated using PCA, MDS, mean-linkage clustering, AMOVA, and Fisher exact tests of FST's, RST's, and haplogroup frequencies. Geographic differentiation in affinities of Middle Eastern populations with Africa and Europe showed distinct contrasts between mtDNA and Y-chromosome data. Specifically, Lebanon's mtDNA shows a very strong association to Europe, while Yemen shows very strong affinity with Egypt and North and East Africa. Previous Y-chromosome results showed a Levantine coastal-inland contrast marked by J1 and J2, and a very strong North African component was evident throughout the Middle East. Neither of these patterns were observed in the mtDNA. While J2 has penetrated into Europe, the pattern of Y-chromosome diversity in Lebanon does not show the widespread affinities with Europe indicated by the mtDNA data. Lastly, while each population shows evidence of connections with expansions that now define the Middle East, Africa, and Europe, many of the populations in the Middle East show distinctive mtDNA and Y-haplogroup characteristics that indicate long standing settlement with relatively little impact from and movement into other populations.

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