Genetic studies on Jews In 2012, two major genetic studies were carried out under the leadership of Harry Ostrer, from the Albert Einstein College of Medicine. The results were published in the Proceedings for the National Academy of Sciences. The genes of 509 Jewish donors from 15 different backgrounds and 114 non-Jewish donors of North African origin were analyzed. Ashkenazi, Sephardi, and Mizrahi Jews were found to be closer genetically to each other than to their long-term host populations, and all of them were found to have Middle Eastern ancestry, together with varying amounts of admixture in their local populations. Mizrahi and Ashkenazi Jews
Ashkenazi Hebrew from Spain in 1492 (or before) the Sephardic pronunciation of the vowels became standard in all these countries, ironing out any differences that previously existed. This makes it harder to adjudicate between the different theories on the relationship between today's pronunciation systems and those of ancient times. Leopold Zunz believed that the Ashkenazi pronunciation was derived from that of Palestine in Geonic times (7th–11th centuries CE), while the Sephardi pronunciation was derived from that of Babylonia. This theory was supported by the fact that, in some respects, Ashkenazi Hebrew resembles the western dialect of Syriac while Sephardi Hebrew resembles the