2013; Henn and others, 2012; Kopelman and others, 2009; Seldin and others, 2006; Tian and others, 2008). We confirm the notion that the Ashkenazi, North African, and Sephardi Jews share substantial genetic ancestry and that they derive it from Middle Eastern and European populations, with no indication of a detectable Khazar contribution to their genetic origins." The authors also reanalyzed the 2012 study of Eran Elhaik, and found that "The provocative assumption that Armenians and Georgians could serve as appropriate proxies for Khazar descendants is problematic for a number of reasons as the evidence for ancestry among Caucasus populations do not reflect Khazar ancestry". Also, the authors found that "Even if it were allowed that Caucasus affinities could represent Khazar ancestry, the use of the Armenians and Georgians as Khazar proxies is particularly poor, as they represent the southern part of the Caucasus region, while the Khazar Khaganate was centered in the North Caucasus and further to the north. Furthermore, among populations of the Caucasus, Armenians and Georgians are geographically the closest to the Middle East, and are therefore expected a priori to show the greatest genetic similarity to Middle Eastern populations." Concerning the similarity of South Caucasus populations to Middle Eastern groups which was observed at the level of the whole genome in one recent study (Yunusbayev and others, 2012). The authors found that "Any genetic similarity between Ashkenazi Jews and Armenians and Georgians might merely reflect a common shared Middle Eastern ancestry component, actually providing further support to a Middle Eastern origin of Ashkenazi Jews, rather than a hint for a Khazar origin". The authors claimed "If one accepts the premise that similarity to Armenians and Georgians represents Khazar ancestry for Ashkenazi Jews, then by extension one must also claim that Middle Eastern Jews and many Mediterranean European and Middle Eastern populations are also Khazar descendants. This claim is clearly not valid, as the differences among the various Jewish and non-Jewish populations of Mediterranean Europe and the Middle East predate the period of the Khazars by thousands of years". A 2014 study by Carmi et al. published by Nature Communications found that the Ashkenazi Jewish population originates from an approximately even mixture of Middle Eastern and European ancestry. According to the authors, that mixing likely occurred some 600–800 years ago, followed by rapid growth and genetic isolation (rate per generation 16–53%;). The study found that all Ashkenazi Jews