Haplogroups

The nonrecombining portion of the human Y-chromosome is paternally inherited, and passes from father to son essentially unchanged. But occasionally a random change known as a polymorphism or mutation occurs. Such mutations—also called markers—serve as beacons and can be mapped. When geneticists identify a mutation in a DNA test, they try to determine when it first occurred and in which geographic region of the world. Thus, the Y-chromosome haplogroup can be used to trace the paternal line of the individual (Jobling and Tyler-Smith, 2003). The Y-DNA tests are available only for men.

Because Y-DNA haplogroups are closely linked to geography and populations, they serve as important genetic indicators to trace paternal lineages and their ancient origins. This study has relied on the Y-DNA haplogroup as the primary gauge for exploring deep ancestry of the MRCAs of the Jats.