page_title: Genealogical DNA test
section_title: SNP markers and Haplogroups
hierarchical_section_title: Genealogical DNA test / Types of tests / Y chromosome (Y-DNA) testing / SNP markers and Haplogroups
caption_attribution_description: English: shows current distribution of prevailing Y-DNA-haplogroups in Europe on the sufficient available data of the youngest clades, c. 20 kya old. It should be noted that the younger clades of R1a and R1b(R-Z282, R-M458, R-Z284, R-Z93, R-L664, R-M269, R-S116, R-DF27, R-L21, R-U152, R-U106) not in bold script are marked by their own shade/color only to show the prevailing internal structure of these haplogroups, in areas where a whole R1a or R1b haplogroup would prevail as compared to their contemporary haplogroups on the map in bold. Regions, where a haplogroup is leading by not more than 5%, are painted striped. Português: Distribuição dos haplogrupos do cromossoma Y na Europa
context_page_description: A genealogical DNA test is a DNA-based test which looks at specific locations of a person's genome, in order to find or verify ancestral genealogical relationships or to estimate the ethnic mixture of an individual. Since different testing companies use different ethnic reference groups and different matching algorithms, ethnicity estimates for an individual will vary between tests, sometimes dramatically.
  Three principal types of genealogical DNA tests are available, with each looking at a different part of the genome and useful for different types of genealogical research: autosomal, mitochondrial, and Y-DNA.
  Autosomal tests may result in a large amount of DNA matches, along mixed male and female lines, each match with an estimated distance in the family tree. However, due to the random nature of which and how much DNA is inherited by each tested person from their common ancestors, precise conclusions can only be made for close relations. Traditional genealogical research, and the sharing of family trees, is typically required for interpretation of the results. Autosomal tests are also used in estimating ethnic mix.
  MtDNA and Y-DNA tests are much more objective.
context_section_description: A person's haplogroup can often be inferred from their STR results, but can be proven only with a Y-chromosome SNP test (Y-SNP test).
  A single-nucleotide polymorphism (SNP) is a change to a single nucleotide in a DNA sequence. Typical Y-DNA SNP tests test about 20,000 to 35,000 SNPs. Getting a SNP test allows a much higher resolution than STRs. It can be used to provide additional information about the relationship between two individuals and to confirm haplogroups.
  All human men descend in the paternal line from a single man dubbed Y-chromosomal Adam, who lived probably between 200,000 and 300,000 years ago. A 'family tree' can be drawn showing how men today descend from him. Different branches of this tree are different haplogroups. Most haplogroups can be further subdivided multiple times into sub-clades. Some known sub-clades were founded in the last 1000 years, meaning their timeframe approaches the genealogical era (c.1500 onwards).
  New sub-clades of haplogroups may be discovered when an individual tests, especially if they are non-European. Most significant of these new discoveries was in 2013 when the haplogroup A00 was discovered, which required theories about Y-chromosomal Adam to be significantly revised. The haplogroup was discovered when an African-American man tested STRs at FamilyTreeDNA and his results were found to be unusual. SNP testing confirmed that he does not descend patrilineally from the "old" Y-chromosomal Adam and so a much older man became Y-Chromosomal Adam.
caption: The most common Y-DNA-haplogroup in different regions in Europe