Abraham’s Chromosomes
http://www.aish.com/ci/sam/48944786.html
Jewish Genes
http://www.aish.com/ci/sam/48937817.html
The Cohanim - DNA Connection
http://www.aish.com/ci/sam/48936742.html
ping
Two factors worked together to help create the modern outcome of the consistency of “Jewish genes” among modern Jews around the world.
The first was a dominant antipathy of Jewish religious leaders to conversion of non-Jews.
The influence of the first source may have become diminished over the past 2,012 years were it not for the second - the rejection of the Jew as “other”, under law and socially, which helped to segregate the Jew as much a possible. This was seldom relaxed in the Muslim world, with the exception of a few talented and exceptional Jews who were granted privileges, and it did not start to become relaxed in Europe until the age of Napoleon. By the late 1800s, the present genetic patterns had already become established.