Genetic genealogy
As the field developed, the aims of practitioners broadened, with many seeking knowledge of their ancestry beyond the recent centuries, for which traditional pedigrees can be constructed.
[2] Bryan Sykes, a molecular biologist at Oxford University, tested the new methodology in general surname research.
[5][6][7][8][9] In 2001, GeneTree was acquired by Sorenson Molecular Genealogy Foundation (SMGF),[10] which provided free Y-chromosome and mitochondrial DNA (mtDNA) tests.
However, this can only be remedied by testing more individuals, making geneticists aware of the genetic variation present in currently underrepresented testees.
By 2003, the field of DNA testing of surnames was declared officially to have "arrived" in an article by Jobling and Tyler-Smith in Nature Reviews Genetics.
[27] In 2018, a paper in Science Magazine estimated that a DNA genealogy search on anybody of European descent would result in a third cousin or closer match 60% of the time.
[28] The original Genographic Project was a five-year research study launched in 2005 by the National Geographic Society and IBM, in partnership with the University of Arizona and Family Tree DNA.
These groups include adoptees, foundlings, Holocaust survivors, GI babies, child migrants, descendants of children from orphan trains and people with slave ancestry.
Members of the genetic genealogy community have been credited with making useful contributions to knowledge in the field, an example of citizen science.
[40] Care should be taken to avoid overstating the recency of a relationship however, as a mutation in the mitochondrial genome will only occur every 1000 to 3000 years on average.
SNP testing is necessary to prove a true relationship, as these mutations are considered so rare that they could only have arisen in one individual in history.
This has been exploited in recent times to identify the defining mutations of noble and royal lineages, such as the Stewarts of Scotland[45] and the Uí Briúin dynasty of Ireland.
These family trees may be extended if recollections of earlier generations were preserved through oral tradition or written documents.
DNA comparison may offer an alternative means of confirming family relationships of biological parents, but may be confused by adoption or when a mother conceals the identity of the father of her child.
[49] While mitochondrial and Y-chromosome DNA matching offer the most definitive confirmation of ancestral relationships, the information from a tested individual is relevant to a decreasing fraction of their ancestors from earlier generations.
A company offering the test uses computer algorithms and calculations to make a prediction of what percentage of an individual's DNA comes from particular ancestral groups.
Despite this aspect of the tests being heavily promoted and advertised, many genetic genealogists have warned consumers that the results may be inaccurate, and at best are only approximate.
They include the following ancestral components, with their geographical hubs and main associated populations: Genealogical DNA testing methods have been used on a longer time scale to trace human migratory patterns.
For several years, researchers and laboratories from around the world sampled indigenous populations from around the globe in an effort to map historical human migration patterns.
The National Geographic Society's Genographic Project aims to map historical human migration patterns by collecting and analyzing DNA samples from over 100,000 people across five continents.
[60] Law enforcement may use genetic genealogy to track down perpetrators of violent crimes such as murder or sexual assault and they may also use it to identify deceased individuals.
This investigative, or forensic, genetic genealogy technique became popular after the arrest of the alleged Golden State Killer in 2018,[63] but has received significant backlash from privacy experts.
[64][65] However, in May 2019 GEDmatch made their privacy rules more restrictive, thereby reducing the incentive for law enforcement agencies to use their site.
