My research program concerns the population genetics of the peoples of the Eastern Mediterranean and Arabia. In particular, I am interested in studying diversity of the local human populations within the framework of the historical development of various modes of subsistence economy in the region.
Similar to culture, craniofaciometrics and other important biological aspects of the modern Middle Eastern human populations are reported to be correlated with a continuum of traditional subsistence economies (fully nomadic camel pastoralism, semi-nomadic ovicaprid pastoralism, settled farming and town dwelling). Reconstructing the genetic relationships among the human populations in the region is the requisite first step towards establishing the comparative context within which these correlations can be analyzed and determined if causal in nature or due to historical coincidence.
I have already sketched a broad model for the demographic processes that accompanied the development of semi-nomadic ovicaprid pastoralism and fully nomadic camel pastoralism in Syro-Mesopotmia and Arabia using a variety of binary polymorphisms and microsatellite loci carried on the non-recombining region of the Y-chromosome (NRY) in nearly 350 paternally unrelated male subjects. The pattern of NRY genotypic diversity and the time to the most recent common ancestor (TMRCA) estimates for the settled, semi-nomadic and fully nomadic groups in the southern Levant are consistent
with the appearance of Levantine settled agriculturalists over 10 millennia ago, followed by ovicaprid semi-nomadic pastoralism as an offshoot of settled agricultural animal husbandry between the late 7th and the late 4th millennia BCE, followed by the appearance of fully nomadic camel nomadism as an offshoot of southern Levantine ovicaprid semi-nomadism by the end of the 2nd millennium BCE. These results are consistent with the recent archaeological evidence, but contradict the classical view which assumes pastoral nomadism to be the primal mode of subsistence, with nomads episodically pouring out of the Syrian/Arabian Desert and inundating the Fertile Crescent, where they undergo a steady, inexorable sedentarization process. Furthermore, the NRY-haplotype analysis is consistent with the notion that the transition among settled, semi-settled and semi-nomadic modes of subsistence has been a historically recurrent and fluid process, but suggests a single major founding event for camel nomadism. As a practical application, these insights into the land-use history of the region could contribute to placing the study of anthropogenic effects on the diversity of local animal and plant species within a historical framework.
On a parallel track, I have developed a mathematical correction that allows the utilization of mildly non-standard 2-d images in geometric morphometric studies. This correction allows a rapid and easy acquirement of craniofaciometric data from live subjects as well as photographic archives.
Building on this groundwork, I intend to pursue the following major lines of research:
Develop the supporting statistical, morphometric and computer tools.
- Increase the resolution and dependability of the model for genetic inter-relationships by adding more subjects and genotyping more NRY, mtDNA, and nuclear markers.
- Analyze cultural, craniofaciometric, disease, and other biological data within the framework provided by the genetic model above.