Human Y-chromosome DNA haplogroup
In human genetics, a human Y-chromosome DNA haplogroup is a haplogroup defined by specific mutations in the non-recombining portions of DNA on the male-specific Y chromosome (Y-DNA). Individuals within a haplogroup share similar numbers of short tandem repeats (STRs) and single-nucleotide polymorphisms (SNPs).
Source: Wikipedia — Human Y-chromosome DNA haplogroup (CC BY-SA 4.0)