Original sentence: A second study (2006) by Behar et al, based on haplotype analysis of mitochondrial DNA (mtDNA), suggests that about 40% of the current Ashkenazi population is descended matrilineally from just four women.One, a 2000 study of haplotypes by Hammer et al suggests that Y chromosomes of most Ashkenazi and Sephardic Jews are of Middle Eastern origin, containing mutations that are also common among Palestinians and other Middle Eastern peoples, yet are uncommon in the general European population.These results strongly suggest that the male ancestors of the Ashkenazi Jews can be traced primarily to the Middle East.Two recent genetic research studies have called the main thesis of The Thirteenth Tribeinto question
Edited sentence: A second study (2006) by Behar et al, based on haplotype analysis of mitochondrial DNA (mtDNA), shows that about 40% of the current Ashkenazi population is descended matrilineally from just four women.One, a 2000 study of haplotypes by Hammer et al shows that Y chromosomes of most Ashkenazi and Sephardic Jews are of Middle Eastern origin, containing mutations that are also common among Palestinians and other Middle Eastern peoples, yet are uncommon in the general European population.These results indicate that the male ancestors of the Ashkenazi Jews can be traced primarily to the Middle East.Two recent genetic research studies have disproved the main thesis of The Thirteenth Tribe