Surname project
Encyclopedia
A surname DNA project is a genetic genealogy
project which uses genealogical DNA test
s to trace male lineage.
Because surname
s are passed down from father to son in many cultures, and Y-chromosomes (Y-DNA) are passed from father to son with a predictable rate of mutation, people with the same surname can use genealogical DNA testing to determine if they share a common ancestor
within recent history.
When two males share a surname, a test of their Y-chromosome markers will determine either that they are not related, or that they are related. If they are related, the number of markers tested and the number of matches at those markers determines the range of generations until their most recent common ancestor
(MRCA). If the two tests match on 37 markers, there is a 50% probability that the MRCA was less than 5 generations ago and a 90% probability that the MRCA was less than 17 generations ago.
s. For example, at DYS455, the results will show 8, 9, 10, 11 or 12 repeats. The specific results for a given individual are referred to as a haplotype
. When a surname project has enough participants, it can determine one or more modal haplotype
s for the surname.
companies. Group rates may be obtained for surname projects and some labs even store the submitted samples for a number of years at no cost to the participants. This enables additional tests to be performed as they become available.
, based upon the results of the number of alleles in certain positions called markers. These "markers" have been chosen for their demonstrated ability to predict the haplogroup of the tested individual. They are tightly guarded proprietary information. Each testing company used a different set, although many are overlapping. This has allowed Y-STR database websites such as Ybase and Ysearch to convert scores from several companies and find matches within their database for submitted results.
Genetic genealogy
Genetic genealogy is the application of genetics to traditional genealogy. Genetic genealogy involves the use of genealogical DNA testing to determine the level of genetic relationship between individuals.-History:...
project which uses genealogical DNA test
Genealogical DNA test
A genealogical DNA test examines the nucleotides at specific locations on a person's DNA for genetic genealogy purposes. The test results are not meant to have any informative medical value and do not determine specific genetic diseases or disorders ; they are intended only to give genealogical...
s to trace male lineage.
Because surname
Surname
A surname is a name added to a given name and is part of a personal name. In many cases, a surname is a family name. Many dictionaries define "surname" as a synonym of "family name"...
s are passed down from father to son in many cultures, and Y-chromosomes (Y-DNA) are passed from father to son with a predictable rate of mutation, people with the same surname can use genealogical DNA testing to determine if they share a common ancestor
Most recent common ancestor
In genetics, the most recent common ancestor of any set of organisms is the most recent individual from which all organisms in the group are directly descended...
within recent history.
When two males share a surname, a test of their Y-chromosome markers will determine either that they are not related, or that they are related. If they are related, the number of markers tested and the number of matches at those markers determines the range of generations until their most recent common ancestor
Most recent common ancestor
In genetics, the most recent common ancestor of any set of organisms is the most recent individual from which all organisms in the group are directly descended...
(MRCA). If the two tests match on 37 markers, there is a 50% probability that the MRCA was less than 5 generations ago and a 90% probability that the MRCA was less than 17 generations ago.
Markers
A Y-DNA test ranges from 10 to 100 markers on the Y chromosome. Most surname projects suggest at least 25 markers. Test results tell how many repeats a given subject has at a particular marker; the variations of repeats are known as alleleAllele
An allele is one of two or more forms of a gene or a genetic locus . "Allel" is an abbreviation of allelomorph. Sometimes, different alleles can result in different observable phenotypic traits, such as different pigmentation...
s. For example, at DYS455, the results will show 8, 9, 10, 11 or 12 repeats. The specific results for a given individual are referred to as a haplotype
Haplotype
A haplotype in genetics is a combination of alleles at adjacent locations on the chromosome that are transmitted together...
. When a surname project has enough participants, it can determine one or more modal haplotype
Modal haplotype
A modal haplotype is an ancestral haplotype derived from the DNA test results of a specific group of people, using genetic genealogy.The two most commonly discussed modal haplotypes are the Atlantic Modal Haplotype and the Cohen Modal Haplotype...
s for the surname.
Testing companies
Surname projects are now being hosted by testingGenealogical DNA test
A genealogical DNA test examines the nucleotides at specific locations on a person's DNA for genetic genealogy purposes. The test results are not meant to have any informative medical value and do not determine specific genetic diseases or disorders ; they are intended only to give genealogical...
companies. Group rates may be obtained for surname projects and some labs even store the submitted samples for a number of years at no cost to the participants. This enables additional tests to be performed as they become available.
Haplogroups
The Y chromosome has been studied intensely and divided into Human Y-chromosome DNA haplogroupsHuman Y-chromosome DNA haplogroups
In human genetics, a Human Y-chromosome DNA haplogroup is a haplogroup defined by differences in the non-recombining portions of DNA from the Y chromosome ....
, based upon the results of the number of alleles in certain positions called markers. These "markers" have been chosen for their demonstrated ability to predict the haplogroup of the tested individual. They are tightly guarded proprietary information. Each testing company used a different set, although many are overlapping. This has allowed Y-STR database websites such as Ybase and Ysearch to convert scores from several companies and find matches within their database for submitted results.