religious usage and sometimes in modern usage, however, the Mizrahim are also termed Sephardi due to similar styles of liturgy, despite independent evolutions from Sephardim proper. Thus, among Mizrahim there are Iranian Jews, Iraqi Jews, Egyptian Jews, Sudanese Jews, Tunisian Jews, Algerian Jews, Moroccan Jews, Lebanese Jews, Kurdish Jews, Libyan Jews, Syrian Jews, and various others. The Yemenite Jews ("Teimanim") from Yemen are sometimes included, although their style of liturgy is unique and they differ in respect to the admixture found among them to that found in Mizrahim. Additionally, there is a difference between the pre-existing Middle Eastern and North African Jewish communities as distinct from the descendants of those Sephardi migrants who established themselves in the Middle East and North Africa after the expulsion of the Jews from Spain by the Catholic Monarchs in 1492, and in 1497 from the expulsion decreed in Portugal. Despite this diversity, Ashkenazi Jews represent the bulk of modern Jewry, estimated at between 70% and 80% of all Jews worldwide; prior to World War II and the Holocaust however, it was 90%. Ashkenazim developed in Europe, but underwent massive emigration in search of better opportunities and during periods of civil strife and warfare. As a result of this, they became the overwhelming majority of Jews in the New World continents and countries, which previously were without native European or Jewish populations. These include the United States, Mexico, Canada, United Kingdom, Argentina, Australia, Brazil and South Africa, but with Venezuela and Panama being exceptions since Sephardim still compose the majority of the Jewish communities in these two countries. In France, more recent Sephardi Jewish immigrants from North Africa and their descendants now outnumber the pre-existing Ashkenazim. Genetic studies Despite the evident diversity displayed by the world's distinctive Jewish populations, both culturally and physically, genetic studies have demonstrated most of these to be genetically related to one another, having ultimately originated from a common ancient Israelite population that underwent geographic branching and subsequent independent evolutions. A study published by the National Academy of Sciences stated that "The results support the hypothesis that the paternal gene pools of Jewish communities from Europe, North Africa, and the Middle East descended from a common Middle Eastern ancestral population, and suggest that most Jewish communities have remained relatively isolated from neighboring non-Jewish communities during and after the Diaspora." Researchers expressed surprise at the remarkable genetic uniformity they found among modern