Genetic studies of Jews are part of the population genetics discipline and are used to analyze the ancestry of Jewish populations, complementing research in other fields such as history, linguistics, archaeology, and paleontology. These studies investigate the origins of various Jewish ethnic divisions. In particular, they examine whether there is a common genetic heritage among them. The medical genetics of Jews are studied for population-specific diseases.
Studies on Jewish populations have been principally conducted using three types of genealogical DNA tests: autosomal (atDNA), mitochondrial (mtDNA), and Y-chromosome (Y-DNA). atDNA tests, which look at the entire DNA mixture, show that Jewish populations have tended to form genetic isolates – relatively closely related groups in independent communities with most in a community sharing significant ancestry – with Ashkenazi Jews forming the largest such group.[1] mtDNA and Y-DNA tests look at maternal and paternal ancestry respectively, via two small groups of genes transmitted only via female or male ancestors.[2]
^Blazer, Dan G.; Hernandez, Lyla M., eds. (2006). "The Importance of Ancestral Origin". Genes, Behavior, and the Social Environment: Moving Beyond the Nature/Nurture Debate. National Academies Press. p. 100. ISBN978-0-309-10196-7. Archived from the original on 9 February 2023. Retrieved 22 October 2017.
^Lewontin 2012, "Ordinary genetics is not sufficient... If one of my ancestors four generations ago were black, there is a good chance I would have inherited none of her pigment genes or so few that they would not be apparent in my own skin color. This random inheritance of genes makes it very difficult to reconstruct the variety of ancestors in remote past generations. Fortunately for those interested in the reconstruction of ancestry there are two useful exceptions to the rule that we inherit only a random one of the two sets of genetic information possessed by each of our parents... The Y chromosome carries very few genes... Thus, by examining the Y chromosome DNA from a group of males in some generation and comparing it to the Y chromosomes of various other populations, we can reconstruct the contribution of males from various sources in previous generations to the present population... Our mitochondria, then, provide us, both male and female, with a record of our maternal ancestry, uncontaminated by their male partners.".
^Katsnelson, Alla (3 June 2010). "Jews worldwide share genetic ties". Nature. doi:10.1038/news.2010.277.
^Frudakis, Tony (2010). "Ashkenazi Jews". Molecular Photofitting: Predicting Ancestry and Phenotype Using DNA. Elsevier. p. 383. ISBN978-0-08-055137-1. Archived from the original on 9 February 2023. Retrieved 22 October 2017.