This project is about a Y-haplogroup, which defines a group of men by a shared set of inherited features in the DNA of their Y-chromosome. This implies they have a patrilineal ancestor in common, because only males carry a Y-chromosome, which they inherit from their father. The major Y-haplogroups were formed thousands of years ago, and therefore each group can today include thousands to millions of men. For an introduction, you can visit the Y-DNA Haplogroups project, the DNA Testing project, or start at the beginning with the DNA Primer project.
Naming Changes
On the ISOGG Y-DNA tree, version 12.1 (1-Jan-2017), the SNP "V148" is considered diagnostic for haplogroup A0-CTS2809/L991, but is no longer the primary SNP choice for identifying this haplogroup. The SNP CTS2809/L991 is now preferred, but the haplogroup names "A-V148" and "A-CTS2809/L991" refer to the exact same haplogroup since the two SNPs are understood at this time to be phylogenetically equivalent. The designation "A0-CTS2809/L991" is recommended for this haplogroup, and "A0-L991" or "A0-CTS2809" are also fine since L991 and CTS2809 are synonymous names for the exact same SNP.
- Y-Haplogroup A @ Wikipedia
- Y-Haplogroup A @ ISOGG
- A (Y-DNA) @ Geni
- Y-DNA haplogroups @ Geni