Named with a dizzying array of letters and numbers, your haplogroup attempts to describe the deep ancestral history of your direct maternal or direct paternal line.
Haplo, is short for haploid, and means single. We have a single copy (or version) of YDNA and a single version of mtDNA. Opposed to the other 22 sets of chromosomes, which are diploid, or two, because these chromosomes come in pairs (one from mom, one from dad).
Therefore your haplogroup is like a club you belong to that can only be associated with the ancestors on one single direct line of inheritance. This club membership helps you define where in the world your direct line may have originated. It can also describe your affiliation with a particular special interest group (SIG) within your club that may help you answer some genealogical questions about the origin of your ancestors. This directory of YDNA haplogroups from around the world can help you place your haplogroup on a map
Single changes in your DNA accumulate over time. We call these single changes SNPs (“snips”). Each SNP has a time and a place stamp that lets us know which subgroup you may belong to.
All haplogroups are named with an alternating number and letter pattern. The first letter tells us which club you are in, with all numbers and letters that follow acting like Russian nesting dolls letting us know which SIG you are in. For example, in H2a3b we would say you are in club “H”, in SIG “b” within SIG “3” within SIG “a” within SIG “2.”
Those who share your most detailed SIG are the most like you; you have the same genetic “interests"
The YDNA haplogroup you receive from FTDNA is very general or high-level.
The YDNA haplogroup R-M269, for example lists “R” as the club name and “M269” as the SIG. But there are hundreds of other SIGs under M269 (think of the nesting dolls again).
In general, your haplogroup might be able to tell you a general area in the world where you are from. You may learn more by joining a yDNA haplogroup study or yDNA surname project.
Single nucleotide polymorphisms, frequently called SNPs (pronounced “snips”), are the most common type of genetic variations. Each SNP is a mutation or new branch on the tree. The number of SNPs on which people match within a database can be used to tell how closely related they are.