Sarah Elshazly is an Israeli Muslim, who sometimes substitutes for Judith Apter Klinghoffer, an Israeli Jew who runs a very good and informative blog on the History News Network.
During one of Sarah’s stints, she posted the following article by David Storobin, Esq. entitled “Palestinian Genes Show Arab, Jewish, European and Black-African Ancestry“.
Palestinians…differ from other Arabs in some ways. As the web site for Harper’s Magazine reported, one study showed that Jews and Palestinians have common ancestry that is so recent that it is highly likely that at least some of the Palestinian blood actually descends from Jews.  Another study by New York University confirmed a remarkable similarity between Jewish and Palestinian genes. “Jews and Arabs are all really children of Abraham,” said Dr. Harry Ostrer, director of the Human Genetics Program at New York University School of Medicine, who worked on the study. “And all have preserved their Middle Eastern genetic roots over 4,000 years.
Several studies have shown that Palestinians have a larger than usual (among Arabs) European blood. This may be explained by the Crusades and the establishment of a Crusader Kingdom in medieval times. It is highly likely that at least some percentage of the Palestinian population mixed with Europeans, either through intermarriage or rape of Arab women by Europeans, as well as [the rape of] European women by Arabs. Additionally, cities with significant Palestinian populations, including Bethlehem, Nazareth and Jerusalem, are sites of many Christian holy landmarks, which draw a large number of European tourists. This, too, may have played a role in the disproportionate amount of European genes found among Palestinians.
In more recent times, among Palestinian Muslims, there is a significant number of people who are recent immigrants from other Arab states. Official records of the Ottoman Empire (colonial power until WWI) and Britain (colonial power from the 1920’s to 1948) show that there was very significant Islamic immigration into holy land. In some years, there were more Muslim new-comers than Jewish.
 Harper’s Magazine Web Site. Reported on 11/21/2004 at: http://www.harpers.org/Genetics.html