---
title: "Genetic genealogy"
chunk: 1/3
source: "https://en.wikipedia.org/wiki/Genetic_genealogy"
category: "reference"
tags: "science, encyclopedia"
date_saved: "2026-05-05T04:14:35.876877+00:00"
instance: "kb-cron"
---

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 by family historians in the 21st century, as DNA tests became affordable. The tests have been promoted by amateur groups, such as surname study groups or regional genealogical groups, as well as research projects such as the Genographic Project.
As of 2019, about 30 million people had been tested. 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.

== History ==

The investigation of surnames in genetics can be said to go back to George Darwin, a son of Charles Darwin and Charles' first cousin Emma Darwin. In 1875, George Darwin used surnames to estimate the frequency of first-cousin marriages and calculated the expected incidence of marriage between people of the same surname (isonymy). He arrived at a figure of 1.5% for cousin-marriage in the population of London, higher (3%-3.5%) among the upper classes and lower (2.25%) among the general rural population.

=== Surname studies ===
A famous study in 1998 examined the lineage of descendants of Thomas Jefferson's paternal line and male lineage descendants of the freed slave Sally Hemings.
Bryan Sykes, a molecular biologist at Oxford University, tested the new methodology in general surname research. His study of the Sykes surname, published in 2000, obtained results by looking at four STR markers on the male chromosome. It pointed the way to genetics becoming a valuable assistant in the service of genealogy and history.

=== Direct-to-consumer DNA testing ===

In 2000, Family Tree DNA was the first company to provide direct-to-consumer genetic testing for genealogy research. It initially offered eleven-marker Y-chromosome STR tests and HVR1 mitochondrial DNA tests but not multi-generational genealogy tests. In 2001, GeneTree was acquired by Sorenson Molecular Genealogy Foundation (SMGF), which provided free Y-chromosome and mitochondrial DNA (mtDNA) tests. GeneTree later returned to genetic testing in conjunction with its Sorenson parent company until it was acquired by Ancestry.com in 2012.
In 2007, 23andMe was the first company to offer saliva-based direct-to-consumer testing, and the first to use autosomal DNA for ancestry testing. An autosome is one of the 22 chromosomes other than the X or Y chromosomes. They are transmitted from all ancestors in recent generations and so can be used to match with other testers who may be related. Companies were later also able to use this data to estimate how much of each ethnicity a customer has. FamilyTreeDNA entered this market in 2010, followed by AncestryDNA in 2012, and the number of tests grew rapidly. By 2018 autosomal testing had become the predominant type of test, and for many companies the only test they offered.
MyHeritage launched its testing service in 2016, allowing users to use cheek swabs to collect samples, and introduced new analysis tools in 2019: autoclusters (grouping matches visually into clusters) and family tree theories (suggesting conceivable relations between DNA matches by combining several MyHeritage trees and the Geni global family tree). Living DNA, founded in 2015, uses SNP chips to provide reports on autosomal ancestry, Y, and mtDNA ancestry.
By 2019, the combined total of customers at the four largest companies was 26 million. By August 2019, it was reported that about 30 million people had had their DNA tested for genealogical purposes.
GEDmatch said in 2018 that about half of their one million profiles were American. Due to the limited geographical distribution of DNA testees, databases and results limit knowledge of variation present in other racial groups. However, this can only be remedied by testing more individuals, making geneticists aware of the genetic variation present in currently underrepresented testees.

=== Genetic genealogy revolution ===
The publication of The Seven Daughters of Eve by Sykes in 2001, which described the seven major haplogroups of European ancestors, helped push personal ancestry testing through DNA tests into wide public notice. With the growing availability and affordability of genealogical DNA testing, genetic genealogy as a field grew rapidly. 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. The number of firms offering tests, and the number of consumers ordering them, rose dramatically. 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.

=== Genographic Project ===

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. Its goals were primarily anthropological. The project announced that by April 2010 it had sold more than 350,000 of its public participation testing kits, which test the general public for either twelve STR markers on the Y chromosome or mutations on the HVR1 region of the mtDNA.
The phase of the project in 2016 was Geno 2.0 Next Generation. As of 2018, almost one-million participants in over 140 countries had joined the project. In 2019, it was announced that from the end of May no further testing kits would be sold and results would only be available to the end of 2020.

=== Typical customers and interest groups ===