As haplotypes increase in size, Chromosomal recombination fragments them in a generation dependent process.

A30::DQ2 can be written in an extended form covering the major histocompatibility loci as follows: HLA A*3002 : Cw*0501 : B*1801 : DRB1*0301 : DQA1*0501 : DQB1*0201.

Despite that large areas of Northern Africa have not been studies by HLA, A30::DQ2 appears to have originate southwest of is current mode in Sardinia.

Many older studies did not have the resolution to detect the haplotype below a frequency of 1 percent, but a variety of evidence suggests that it declines to the northeast to trace levels.

The B-DR component shows a similar distribution, but lacks adequate testing to the south to resolve its most southern extent.

Because the haplotype is indifferent to Cw allele the level is high in the Basque of Northern Spain.

Subsequently, studies by Antonio Arniaz-Villena and 4 other groups on HLA Class I loci revealed that allele frequency patterns of the Northwestern Mediterranean clustered together and with peoples of North Africa and the Middle East.

The frequency of this allele is highest in Zambia's Lusaka (23.3%) and Zimbabwe Harare Shona (14.7%) but is also high in Senegal, Cameroon, Moroccan Berbers, Kenya and indigenous South Africans.

The DR3-DQ2 component is found at high frequencies in the Irish, but in strong linkage disequilibrium in the AH8.1 haplotype.

[30] Taken together, A30-Cw5-B18-DR3-DQ2's origin among peoples with deep Eurasian ancestry is highly unlikely, and indicates that this haplotypes abundance in Sardinia is a likely consequence of a founder effect or positive selection and other genetic factors.

[1][6][22][23][24] Trees that place Sardinians together with Eastern Mediterranean peoples have difficulty explaining the origin of the haplotype.

While haplotypes have a higher threshold of detection, Cw5-B18 has not been detected in any Eastern Mediterranean people; the B18-DR3 is also rare to Sardinia's East except in the Italians, Swiss and Albanians (1.8%); and DR3-DQ2 is generally lowest in Europe in the Northeastern Mediterranean.

Consequently, if the haplotype did have a recent common origin in or with the Aegean or Black Sea peoples it would need to have expanded from extremely low frequencies after entry in Sardinia.

[19] Studies of Aegean populations over the last decade have revealed the presence of alleles rare in Eurasia and common in sub-Saharan Africans(See map on page for peoples not effectively surveyed for HLA in North Africa).

This pattern continues in the Western Mediterranean includes the Atlantic coast of Europe (Basque, Pasiegos valley).

Recent archaeological studies in Africa reveal the advancement of pottery traditions and animal husbandry in the Sahel prior to or contemporary with the onset of Southwest Asia's Neolithic period.

In addition, if African contributions to Sardinia were largely a consequence of small numbers of founders prior to the Holocene, given rise in sea levels and low population densities, archaeological observations may not represent early occupation or cultural patterns.

Opportunities for migrations increased as the peopling of the Sahara occurred during the Holocene climatic optimum (9,000 to 5,000 years B.P.

), however more recently there has been a displacement of N. Africa's indigenous peoples by immigrants from Phonecia, Aegean Sea, Italy, Arabia.

This is a common problem creating false assumptions over a wide area of molecular anthropology.

However comparing the distribution of A*3001 and A*3002 indicates A*3001 is spread widely with a bimodal distribution (India and West Africa) and its distribution includes regional populations at the periphery of the Old World, whereas A*3002 is spread over East and Northwest Africa and the Western Mediterranean, with frequencies that fall quickly moving East to West along the Northeastern Indian Ocean from Southern Arabia.