Monday, January 24, 2011

An update on the use of ADMIXTURE for analysing Middle Eastern Populations

I thought it would be helpful to add some context to the discussion of posts on Middle East ADMIXTURE results.

The November Assyrians article is based on earlier work:  A Simple Demic Diffusion Model for Syria which proposes that Middle East ADMIXTURE results indicate a diffusion process of formerly isolated populations.

Subsequent articles establish the basis on which Middle Eastern populations can be ordered:  Syria to Assyria:  3500 years of Demic Diffusion, The Coalescent in a Continuous, Finite, Linear Population and Fertile Crescent Components do the Wilson Wakeley Model.

Eurogenes K10 Middle East ADMIXTURE results place the Assyrian and other Middle East populations in context of each other.  The ordering of these results is based on the idea that the "West Asian" represents a southward bound diffusion process, while the "Southwest Asian" component represents a northward bound diffusion process.  In Behar et al, Revisited, I place the Eurogenes K10 Middle East ADMIXTURE result in the context of the Behar et al 2010 primary component cluster plot.

Finally, Assyrians and the ADMIXTURE Southwest Asian Component Revisited  reexamines earlier work regarding gene flow of the Middle East Southwest Asian Component.  This result, attributed to the recent Chiaroni et al paper, complicates the results that can be inferred from Middle East ADMIXTURE data.  At a minimum, it implies that a diffusion process for the Southwest Asian component is multi directional. Additionally, ADMIXTURE itself has limitations and cannot be used to strictly trace phylogeny.  More accurate methods, such as y-chromosome statistical analysis, are required to establish origin and date phylogeny.

What is currently missing from published works is an attempt to correlate ADMIXTURE autosomal results with those of more precise y-chromosome results.

It should be noted that in the academic literature, there is not yet consensus as to the date of the most recent common ancestor in Jewish populations.  Nor is there a good understanding of the interrelationship and date of Jews with their other J1 and J2 cousins.  ADMIXTURE results can be used a guide, but cannot be used to establish the origin or date of most recent common ancestor.

Given the potential political nature of this data, I hope that we will proceed cautiously, considerately and with an open mind.

Further posts discussing the origin and dispersal of the J1 and J2 Haplogroups:
The Origin of Y-chromosome Haplogroup J1:  Another Lake, Other Rivers
Geographical Structure of the Y-chromosomal Genetic Landscape of the Levant:  A coastal-inland contrast
J1-M267 Y lineage marks climate-driven pre-historical human displacements
Neolithic Expansion into Coastal West India
Fertile Crescent Pre-Holocene Expansion of Haplogroup J
The Bedouin
J1 Hap Map
Early Domestication on the Taurus-Zagros Arc
Battaglia et al

No comments:

Post a Comment

Comments have temporarily been turned off. Because I currently have a heavy workload, I do not feel that I can do an acceptable job as moderator. Thanks for your understanding.

Note: Only a member of this blog may post a comment.