A model based on the genetic sequencing of 128 Ashkenazi Jews has reportedly found that Ashkenazi Jews descend from the fusion of Europeans and Middle Eastern Jews in the medieval era approximately 600 to 800 years ago.
All Ashkenazi Jews Alive Today Descend From The 350 Jews Who Lived Approximately 800 Years Ago, Study Finds
Shmarya Rosenberg • FailedMessiah.com
A model based on the genetic sequencing of 128 Ashkenazi Jews has found that Ashkenazi Jews descend from the fusion of Europeans and Middle Eastern Jews in the medieval era approximately 600 to 800 years ago, Ha’aretz reported.
The study – authored by a team of scientists headed by Columbia University's Shai Carmon and published today in the journal Nature Communications – also found that the approximately 10 million Ashkenazim alive today all descend from about 350 people who lived between 25 to 32 generations ago – sometime about 1200 to 1300 CE.
Ashkenazim have a slightly higher rate of genetic diseases than other Europeans because of the recent population bottleneck.
But the study also found Europeans experienced their own bottleneck 20,400 to 22,100 years ago – about the time the last Ice Age was at its worst.
And there was another bottleneck in both the European and African populations before that that scientists believe likely corresponds to a migration by some of the Africans out of Africa and, eventually, into Europe.
The closer parents are genetically – siblings are closer than first cousins, first cousins closer than second cousins, etc. – the greater the chance a recessive disorder caused by a genetic mutation will be shared by both spouses and passed on as a birth defect or genetic other disorder to their children.
Because the Ashkenazi last bottleneck was so recent in genetic terms, and because Ashkenazim often married (and sometimes still marry) into closely related small family groups (think hasidic rebbes marrying the granddaughter or their grandfather or the daughter of their grandfather’s brother’s child, for example), genetic testing for Tay Sachs and other specific genetic disorders before marriage is imperitive.