Paternal haplogroups are families of Y chromosomes defined by specific sets of shared genetic variation. If you are male, the Paternal Haplogroup report provides information about your Y-chromosome haplogroup, which we also call a "paternal haplogroup" because it is passed down from fathers to their sons through the generations.
Only males will receive a Y-chromosome (paternal) haplogroup assignment. Because females do not have Y chromosomes, females do not have paternal haplogroups. However, a woman can learn about the origins of some of her paternal ancestors from the paternal haplogroup of her male-line relatives, such as her father, brothers, and paternal uncles.
Geneticists can use patterns of Y-chromosome variation to trace significant events in human prehistory, such as the migration of people to the Americas or the expansion of agriculture from the Middle East. Because members of a haplogroup tend to be found in the same region of the world, your paternal haplogroup can say something about where some of your male-line ancestors lived. In many cases, we indicate where and when a haplogroup originated in the map section of the report.
Each paternal haplogroup is named with the letter of the major cluster of branches to which it belongs, followed by the name of a representative genetic marker. Our platform includes hundreds of Y-chromosome single nucleotide polymorphisms (SNPs). In contrast, many other genetic ancestry services analyze short tandem repeats (STRs), a different type of genetic variation. Although a single STR may be more informative than a single SNP, SNPs contain more information overall because there are so many more of them.