Haplogroups characterize the early migrations of specific population groups and, therefore, can potentially be used to connect your distant ancestry with a particular geographical region. For the purpose of genetic genealogy, a haplogroup can be defined as all of the descendants of a single individual who first showed a particular single nucleotide polymorphism, or SNP. An SNP is a point on the DNA where a single base changes (e.g. from A to G), which occurs so infrequently that it can be considered unique. This SNP change is then passed down faithfully through generations of the family, and can thus be used to define broad genetic populations. Individuals with the same genetic SNP mutation or "marker" can be linked back to the population where the marker first made an appearance.
Haplogroups are assigned letters of the alphabet, and refinements consist of additional number and letter combinations. Y-chromosome and mitochondrial DNA haplogroups have different haplogroup designations - therefore you have both a paternal haplogroup and a maternal haplogroup.
There is a strong correlation between haplogroups and haplotypes, so it is often, but not always, possible to determine an individual’s haplogroup from their haplotype without further testing.
Also Known As: Y-DNA Haplogroup, mtDNA Haplogroup
The Y-DNA haplogroup R1b originated in Central Asia or Antolia prior to the last period of glaciation, and is now the most common haplogroup in Western Europe. The maternal haplogroup A originated in Asia almost 60,000 years ago and is still prevalent there today. In the United States, Haplogroup A often points to Native American ancestry.