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Monday, March 16, 2009

FTDNA releases updated Haplogroup J2 tree

Family Tree DNA has updated their nomenclature for the various subclades of Haplogroup J2a. They have incorporated the new L24 and L25 SNP's which refer to rs35248080 and rs34534058 respectively. They have also updated the position of P279 above the deletion at DYS 413, which is represented by L26 (rs34126399). This update thus recognizes L24/L25, a sizeable branch of haplogroup J2 which previously was only identified by FTDNA as J2a (M410). However, they'll need to revise yet again, as research from Thomas Krahn seems to show some haplotypes are L24 positive or derived but L25 negative or ancestral. He has also identified a further SNP in these haplotypes which is being called L84. DNA fingerprint seems to show one of the more up to date Haplogroup J trees here . The DNA fingerprint tree is also more legible in part, since it references the SNP 's by name and not by a constantly evolving numbering system.

Monday, March 2, 2009

Haplogroup J in the Gulf of Oman

A paper from Cardenas et al 2008, Y-Chromosome diversity characterizes the Gulf of Oman, analyzes the Y Chromosome diversity for clues to the origins of present day peoples of this region. This part of the world has played a key role in many migratory episodes leaving Africa for Eurasia. Certainly Arabia served as a conduit for the first migrations out of Africa however, the data suggest that the during the Neolithic era, contact with the Levant and Mesopotamia contributed to the very high levels of Haplogroup J found in the Persian Gulf. Just north of the Persian Gulf lies the Fertile Crescent, stretching from Egypt in the West to Iraq in the East. This region is recognized as the birthplace of agriculture during the Neolithic period. While the region was fertile, ancient international trade existed for minerals and other resources. Archaelogical evidence in the form of Ubaid pottery, dated 7000yBP shows ancient contact between the Persian Gulf, Mesopotamia and the Arabian Gulf. Clues from Y Chromosome data, such as the presence of E3b subclade M34 suggest ancient contact between Yemen and the Levant or Egypt. The presence of Haplogroup J2, M172 at frequencies over 10% in UAE could be an indication of migrations from Mesopotamia and/or the Levant.

By far the most frequent haplogroup throughout the Arabian Peninsula is Haplogroup J1 defined by SNP M267. In this study it was found at rates of 58% in Qatar, 72% in Yemen and 34% in UAE. M172 on the other hand was found at rates of 10.3% in UAE, 9.6% in Yemen and 8.4% in Qatar. The authors go on to conclude that the Neolithic period helped disperse Haplogroup J into the Arabian peninsula from the north. They also note the highest levels of diversity seem to emanate from the Persian Gulf coastal areas of UAE, Southern Iran, Oman and South Pakistan.