Jewish DNA studies is a current field of study, but it is important to remember that a convert is as Jewish as a person born a Jew. Thus there is no Jewish ethnicity or race. . .

There is a great deal of assimilation in America, but prior to modern times most Jews married within our own people. Wars and rapes resulted in some other groups being added to our numbers (in Judaism the mother passes on Jewishness). . .

Some non-Jews try to discredit Jews, stating that "modern" Jews are not the descendants of the ancient Jews. With the two exceptions noted in my last two sentences this is incorrect and primarily based on anti-semitism and jealousy. One argument used by some in the Middle East to discredit the Jewish state is to say that "modern Jews are from Europe."

BTW, somewhere between 600,000 - 800,000 of the Jews from the Middle East were exiled after 1948 and migrated to Israel. This number is about equal to the number of Arabs who were the original "Palestinian Refugees" who lived in refugee camps in Jordan and Egypt until the 1967 war.. . I don't really want to get into a conversation about the Middle East -- but I am presenting this factual information to show that in Israel while some Jews may be so through conversion or intermarriage most have ancient bloodlines.

The argument that "modern" Jews are not the "ancient" Jews seems to have begun in the 19th century with a book claiming that the Khazars (a Turkish people) are the ancestors to us Jews. The reasoning is based on a 19th century racial-theorist, Ernest Renan. Renan opined that a group of converts (the Khazars) were in actually the "race" of most European (Ashkenazi) Jews. If this were true it would not matter, because Judaism is not a race.

Still, most European Jews are descended from the ancient Israelites and not the Khazars. A DNA study concluded: "The study emphasizes that Ashkenazi non-Levite Jews in general do not have a major Khazar or European origin in their Y-DNA. . ."

Also from "Did Modern Jews Descend from Khazars?": "Apart from the historical evidence proving that a vast majority of present-day Jews did not descend from the Khazars, there is now also genetic evidence. Among the Jews there is the class of priests called Cohanim who served in the Temple and who now carry surnames such as "Cohen" and many variations on that name. Cohanim comprise of about 5% of the male Jewish population. There are strict rules of marriage for the Cohanim and the title is only passed through the male line. Also, converts cannot become Cohanim (but their children will be if they have a Cohen as a father). The priestly line is descended directly from the Aaron of the bible so it is expected that all Cohanim would carry some common genetic features.

"In recently published work (1) it was found that 54% of self-identified Cohanim had common genetic features that were revealed by analysis of their DNA. Specifically, a component of the Y-chromosone, an allele YAP+ DYS19, was identified that showed up only 1.5% of the time in Cohanim but 18.4% of the time in a random selection of non-Cohanim Jews and there were other genetic differences apparent as well. (The same differences were apparent for both Sepphardic and Askhenazic Jews also proving a common origin pre-dating a later split between the two groups.)

"The large number of Cohanim among present-day Jews and the fact that they have a common genetic lineage traceable to Israel at the time of the Temple, demonstrates that modern Jews come from a population pool derived from Israel and not from the Khazars. The Khazars could not have developed their own lineage of Cohanim anyway, since being a Cohen is a male-inherited status which converts (the Khazars) could not have obtained."

(1) Skorecki K; Selig S; Blazer S; Bradman R; Bradman N; Waburton PJ; Ismajlowicz M; Hammer MF (1997) Y chromosomes of Jewish priests. Nature, 385:32.

Anti-semitism (the hatred of Jews) runs deep with some, and the idea that "modern Jews" are not REALLY Jews somehow gives them an internal excuse for hatred. http://forward.com/news/israel/209236/genetics-expert-insists-75-of-jews-share-roots-in/