Genetic studies on Jews the Jewish diaspora, the genetic composition of Ashkenazi, Sephardi, and Mizrahi Jewish populations show significant amounts of shared Middle Eastern ancestry. According to Behar and colleagues (2010), this is "consistent with a historical formulation of the Jewish people as descending from ancient Hebrew and Israelites of the Levant" and "the dispersion of the people of ancient Israel throughout the Old World". Jews living in the North African, Italian, and Iberian regions show variable frequencies of admixture with the historical non-Jewish population along the maternal lines. In the case of Ashkenazi and Sephardi Jews (in particular Moroccan Jews), who are closely
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