A surname DNA project is a
genetic genealogy
Genetic genealogy is the use of genealogical DNA tests, i.e., DNA profiling and DNA testing, in combination with traditional genealogical methods, to infer genetic relationships between individuals. This application of genetics came to be used ...
project which uses
genealogical DNA test
A genealogical DNA test is a DNA-based test used in genetic genealogy that looks at specific locations of a person's genome in order to find or verify ancestral genealogical relationships, or (with lower reliability) to estimate the ethnic mixt ...
s to trace male lineage.
In most cultures, there are few or no
matrilineal
Matrilineality is the tracing of kinship through the female line. It may also correlate with a social system in which each person is identified with their matriline – their mother's lineage – and which can involve the inheritance ...
surnames, or
matriname
A matrilineal surname or matrinameSykes, Bryan (2001). ''The Seven Daughters of Eve''. W.W. Norton. ; pp. 291–2. Professor Bryan Sykes uses "matriname", only, and states that women adding their own matriname to men's patriname (or "surname" as ...
s, so there are still few or no ''matrilineal'' surname projects. However, DNA tests are equally important for the two sexes (see
genealogical DNA test
A genealogical DNA test is a DNA-based test used in genetic genealogy that looks at specific locations of a person's genome in order to find or verify ancestral genealogical relationships, or (with lower reliability) to estimate the ethnic mixt ...
).
Because
surname
In some cultures, a surname, family name, or last name is the portion of one's personal name that indicates one's family, tribe or community.
Practices vary by culture. The family name may be placed at either the start of a person's full name, ...
s are passed down from father to son in many cultures (''patrilineal''), and
Y-chromosome
The Y chromosome is one of two sex chromosomes ( allosomes) in therian mammals, including humans, and many other animals. The other is the X chromosome. Y is normally the sex-determining chromosome in many species, since it is the presence or abs ...
s (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
Common descent is a concept in evolutionary biology applicable when one species is the ancestor of two or more species later in time. All living beings are in fact descendants of a unique ancestor commonly referred to as the last universal comm ...
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
In biology and genetic genealogy, the most recent common ancestor (MRCA), also known as the last common ancestor (LCA) or concestor, of a set of organisms is the most recent individual from which all the organisms of the set are descended. The ...
(MRCA). If the two tests match on 37 markers, there is a 90% probability that the MRCA was less than five generations ago and a 95% probability that the MRCA was less than eight generations ago.
Markers
A Y-DNA test ranges from 10 to 111 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
allele
An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution.
::"The chro ...
s. For example, at
DYS455, the results will normally show 8, 9, 10, 11, or 12 repeats.
The specific test results for a given individual are referred to as a
haplotype
A haplotype (haploid genotype) is a group of alleles in an organism that are inherited together from a single parent.
Many organisms contain genetic material ( DNA) which is inherited from two parents. Normally these organisms have their DNA org ...
. When a surname project has enough participants' test results, it can group similar test results together and determine a
modal haplotype for each such group of similar test results.
Testing companies
Surname projects are now being hosted by
testing companies. Some labs even store the submitted samples for a number of years, enabling additional tests to be performed as they become available. By far the largest collection of Y-DNA test results is maintained by
Family Tree DNA
FamilyTreeDNA is a division of Gene by Gene, a commercial genetic testing company based in Houston, Texas. FamilyTreeDNA offers analysis of autosomal DNA, Y-DNA, and mitochondrial DNA to individuals for genealogical purpose. With a database of m ...
, including many surname projects that make direct use of those results.
Haplogroups
The Y chromosome has been studied intensely and variations have been divided into
Human Y-chromosome DNA haplogroups
In human genetics, a human Y-chromosome DNA haplogroup is a haplogroup defined by mutations in the non- recombining portions of DNA from the male-specific Y chromosome (called Y-DNA). Many people within a haplogroup share similar numbers of sh ...
, based upon the results of the number of
alleles
An allele (, ; ; modern formation from Greek ἄλλος ''állos'', "other") is a variation of the same sequence of nucleotides at the same place on a long DNA molecule, as described in leading textbooks on genetics and evolution.
::"The chro ...
in certain positions called
markers. These "markers" have been chosen for their demonstrated ability to predict the haplogroup of the tested individual. Each testing company used a different set, although many are overlapping. This had allowed
Y-STR database websites such as
Ybase and
Ysearch (both now defunct) to convert scores from several companies and find matches within their database for submitted results.
See also
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One-name study
A one-name study is a project researching a specific surname, as opposed to a particular pedigree ( ancestors of one person) or descendancy ( descendants of one person or couple). Some people who research a specific surname may restrict their re ...
*
Extinction of surnames
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...
References
Further reading
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External links
Cyndi's List - Surname DNA Studies and ProjectsSurname DNA projects on ISOGG WikiFamily Tree DNA's Surname & Geographical Projects
{{Genealogical DNA test
Genetic genealogy
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