PDA

View Full Version : Analysis of autosomal and Y-chromosomal DNA Suggests West Asian Population Derivation



RCO
09-29-2014, 02:10 PM
ASHG 2014. Analysis of autosomal and Y-chromosomal DNA Suggests West Asian Population Derivation from Northern Middle Eastern Populations in the post-Glacial Period. P. Zalloua1,2, F. Utro3, M. Haber1, L. Parida3, E. Matisoo-Smith34, D. Platt3 1) Genomics Laboratory, Gradute School, Beirut, Lebanon; 2) Harvard School of Public Health, Boston, MA, USA; 3) I.B.M. T. J. Watson Research Center, Yorktown Hgts, NY; 4) University of Otago, Dunedin 9054, New Zealand.

Analysis of Y DNA J and E haplogroups in West Asians (Georgians, Armenians, Turks, Syrians, Lebanese, Jordanians, Saudi Arabians, Yemenis, Kuwaitis) suggest expansions coming primarily from the north (Turkey, Georgia, Armenia), with an early differentiation between those who headed south along the Tigris-Euphrates, versus those who headed south along the Levantine coast. We sought to resolve whether southern variations represented evolution within separate ice age refugia, or evolved from the same northern refugia as suggested by Y chromosome data by revealing population divergence times between Saudi Arabia and Yemen versus Turkey, Syria, and Armenia that predate the post-glacial expansions. We employed IRIS to compute times for grand most recent common ancestors applied between pairs of subjects drawn from Georgians, Armenians, Turks, Syrians, Lebanese, Jordanians, Saudi Arabians and Yemenis, as well as pair-wise FST’s based on the estimated times. We contrasted these results with raw SNP counts and pairwise FST’s obtained from those counts. We applied MDS and hierarchic clustering to identify geographically informative relationships, and observed a clear pattern of a north-to-south gradient. Within the western Middle East, our results suggest population differentiation dates consistent with post Last Glacial expansions, with subsequent population constriction into the Fertile Crescent in the presence of admixture. Our estimates show a north-to-south differentiation time of ~24,800-18,200 y.a., well within the Last Glacial Period. However, the time of J1/J2 haplogroups splits that mark this diversion are dated by BATWING well into the Last Glacial Period, around 31kya. These results place the genetic differentiation of the autosomal genome to be a bit more recent than the J1/J2 split. Expansions into Europe show a somewhat more recent record than those into Africa, with signals that show affinities with particular Middle Eastern regions, suggesting more recent trade impacts.

http://www.ashg.org/2014meeting/abstracts/fulltext/f140122884.htm

Finally a study about J1/J2 with next-gen SNPs
They missed again Iran ?

YFull J tree
http://www.yfull.com/tree/J/

ADW_1981
09-29-2014, 02:44 PM
ASHG 2014. Analysis of autosomal and Y-chromosomal DNA Suggests West Asian Population Derivation from Northern Middle Eastern Populations in the post-Glacial Period. P. Zalloua1,2, F. Utro3, M. Haber1, L. Parida3, E. Matisoo-Smith34, D. Platt3 1) Genomics Laboratory, Gradute School, Beirut, Lebanon; 2) Harvard School of Public Health, Boston, MA, USA; 3) I.B.M. T. J. Watson Research Center, Yorktown Hgts, NY; 4) University of Otago, Dunedin 9054, New Zealand.

Analysis of Y DNA J and E haplogroups in West Asians (Georgians, Armenians, Turks, Syrians, Lebanese, Jordanians, Saudi Arabians, Yemenis, Kuwaitis) suggest expansions coming primarily from the north (Turkey, Georgia, Armenia), with an early differentiation between those who headed south along the Tigris-Euphrates, versus those who headed south along the Levantine coast. We sought to resolve whether southern variations represented evolution within separate ice age refugia, or evolved from the same northern refugia as suggested by Y chromosome data by revealing population divergence times between Saudi Arabia and Yemen versus Turkey, Syria, and Armenia that predate the post-glacial expansions. We employed IRIS to compute times for grand most recent common ancestors applied between pairs of subjects drawn from Georgians, Armenians, Turks, Syrians, Lebanese, Jordanians, Saudi Arabians and Yemenis, as well as pair-wise FST’s based on the estimated times. We contrasted these results with raw SNP counts and pairwise FST’s obtained from those counts. We applied MDS and hierarchic clustering to identify geographically informative relationships, and observed a clear pattern of a north-to-south gradient. Within the western Middle East, our results suggest population differentiation dates consistent with post Last Glacial expansions, with subsequent population constriction into the Fertile Crescent in the presence of admixture. Our estimates show a north-to-south differentiation time of ~24,800-18,200 y.a., well within the Last Glacial Period. However, the time of J1/J2 haplogroups splits that mark this diversion are dated by BATWING well into the Last Glacial Period, around 31kya. These results place the genetic differentiation of the autosomal genome to be a bit more recent than the J1/J2 split. Expansions into Europe show a somewhat more recent record than those into Africa, with signals that show affinities with particular Middle Eastern regions, suggesting more recent trade impacts.

http://www.ashg.org/2014meeting/abstracts/fulltext/f140122884.htm

Finally a study about J1/J2 with next-gen SNPs
They missed again Iran ?

YFull J tree
http://www.yfull.com/tree/J/

This kinda contradicts the latest findings of the neolithic settlements which have been backed by aDNA no?
It's unlikely that J1/J2 expansion times are any older than the late neolithic cultures of Mesopotamia such as Uruk.

Agamemnon
09-29-2014, 03:45 PM
This kinda contradicts the latest findings of the neolithic settlements which have been backed by aDNA no?
It's unlikely that J1/J2 expansion times are any older than the late neolithic cultures of Mesopotamia such as Uruk.

Precisely what I thought when I read this a few days ago... Once more, J is heavily understudied and wild assumptions based on contemporary frequencies don't make this any easier.