While the Jews of today are connected historically and religiously to the Jews of ancient Israel, the DNA evidence also indicates that a significant amount of Jewish ancestry can be traced directly back to their Israelite/Middle Eastern ancestors. However, these ancestors represented a heterogeneous mix of Semitic and Mediterranean groups, even at their very beginnings.
While earlier studies focused on the Middle Eastern component of Jewish DNA, new research has revealed that both Europeans and Central Asians also made significant genetic contributions to Jewish ancestry. Moreover, while the DNA studies have confirmed the close genetic interrelatedness of many Jewish communities, they have also confirmed what many suspected all along: Jews do not constitute a single group distinct from all others. Rather, modern Jews exhibit a diversity of genetic profiles, some reflective of their Semitic/Mediterranean ancestry, but others suggesting an origin in European and Central Asian groups. The blending of European, Semitic, Central Asian and Mediterranean heritage over the centuries has led to today’s Jewish populations.
While the Canaanites were a Western Semitic people indigenous to the area, they appear to have consisted of a diverse ethno-cultural mix from the earliest times. It is from this diverse group that the evolution of the Israelites occurred. Although little is known about these groups, they probably included some of the following populations:
1. Amorites: Western Semites like the Canaanites. They were probably the pastoral nomadic component of the Canaanite people.
2. Hittites: A non-Semitic people from Anatolia and Northern Syria.
3. Hurrians (Horites): A non-Semitic people who inhabited parts of Syria and Mesopotamia. Many kings of the early Canaanite city-states had Hurrian names.
4. Amalekites: Nomads from southern Transjordan. Even inimical references to this group in the Hebrew Bible “tacitly” acknowledge that the Israelites and Amalekites shared a common ancestry.
5. Philistines: Referred to in ancient texts as “Sea Peoples.” They invaded and settled along the coasts of ancient Canaan. Their culture appears to stem from that of Mycenae.
(Dever 2003, pp. 219-220).
Ironically, however, many scholars believe the Ashkenazi population probably had its earliest roots in Rome, where Jews began to establish communities as early as the second century B.C. While some of these Jews were brought to Rome as slaves, others settled there voluntarily. There were as many as 50,000 Jews in and around Rome by the first century CE, most who were “poor, Greek-speaking foreigners” scorned for their poverty and slave status (Konner 2003, p. 86). Eventually, however, many of these slaves gained their freedom, continuing to live in and around Rome.
By 600 CE, Jews were present in many parts of Europe, with small settlements in Germany, France and Spain. More to the east, there were also small Jewish settlements along the Black Sea, as well as larger communities in Greece and the Balkans (Konner 2003, p. 110).
By the 12th-13th centuries CE, Jews were expelled from many countries of Western Europe, but were granted charters to settle in Poland and Lithuania (Ostrer 2001). The Ashkenazi Jewish population expanded rapidly in Eastern Europe, growing from an estimated 15,000-25,000 people in the 13th-15th centuries, to two million by 1800 and eight million in 1939 (Ostrer 2001, Behar 2004b). Thus, Jewish settlement in Eastern Europe became the dominant culture of the European Jews, and then of most Jews throughout the world.
For anyone like me who loves history told through genes, this article from 2005 is a complete goldmine. Newer data has come out that does not radically contradict anything found here.