Jump to content

Genealogical DNA test: Difference between revisions

From Wikipedia, the free encyclopedia
Content deleted Content added
revert - rm promotional link disguised as a ref
 
Line 1: Line 1:
{{Short description|DNA-based genetic test}}
{{TOCright}}
{{For|a non-technical introduction to genetics in general|Introduction to genetics}}
{{Use dmy dates|date=August 2021}}
{{genetic genealogy}}
A '''genealogical DNA test''' is a [[DNA]]-based [[Genetic testing|genetic 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 [[ethnicity|ethnic]] mixture of an individual. Since different testing companies use different ethnic reference groups and different matching algorithms, ethnicity estimates for an individual 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 being useful for different types of genealogical research: [[Genealogical DNA test#Autosomal DNA (atDNA) testing|autosomal]] (atDNA), [[Genealogical DNA test#Mitochondrial DNA (mtDNA) testing|mitochondrial]] (mtDNA), and [[Genealogical DNA test#Y-chromosome (Y-DNA) testing|Y-chromosome]] (Y-DNA).
A '''genealogical DNA test''' involves examining the [[nucleotide]]s at specific locations on a person's [[DNA]]. The tests results are meant to have no informative medical value and do not determine specific genetic diseases or disorders (see possible exceptions in ''[[#Medical information|Medical information]]'' below); they are intended only for use in [[genetic genealogy]].

Autosomal tests may result in a large number of DNA matches to both males and females who have also tested with the same company. Each match will typically show an estimated degree of relatedness, i.e., a close family match, 1st-2nd cousins, 3rd-4th cousins, etc. The furthest degree of relationship is usually the "6th-cousin or further" level. However, due to the random nature of which, and how much, DNA is inherited by each tested person from their common ancestors, precise relationship conclusions can only be made for close relations. Traditional [[genealogy|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. However, they give considerably fewer DNA matches, if any (depending on the company doing the testing), since they are limited to relationships along a strict [[Matrilineality|female line]] and a strict [[Patrilineality|male line]] respectively. MtDNA and Y-DNA tests are utilized to identify [[archeological culture]]s and migration paths of a person's ancestors along a strict mother's line or a strict father's line. Based on MtDNA and Y-DNA, a person's [[haplogroup]](s) can be identified. The mtDNA test can be taken by both males and females, because everyone inherits their mtDNA from their mother, as the [[mitochondrial DNA]] is located in the egg cell. However, a Y-DNA test can only be taken by a male, as only males have a [[Y chromosome|Y-chromosome]].


==Procedure==
==Procedure==
[[File:From_spit_to_DNA-sample.webm|thumb|''How to obtain genotypes from spit.'' The video shows the process of extracting genotypes from a human spit sample using a [[DNA microarray]], which is the most common method used in genetic genealogy.]]
The general procedure for taking a genealogical DNA test involves taking a painless cheek-scraping at home and mailing the sample to a genetic genealogy laboratory for testing. Some laboratories use mouth wash or chewing gum instead of cheek swabs. Some laboratories offer to store DNA samples for ease of future testing. All laboratories will destroy the DNA sample upon request by the customer, guaranteeing that a sample is not available for further analysis.

A genealogical DNA test is performed on a DNA sample obtained by cheek-scraping (also known as a [[buccal swab]]), spit-cups, [[mouthwash]], or [[chewing gum]]. Typically, the sample collection uses a home test kit supplied by a service provider such as [[23andMe]], [[Ancestry.com#AncestryDNA|AncestryDNA]], [[Family Tree DNA]], or [[MyHeritage]]. After following the kit instructions on how to collect the sample, it is returned to the supplier for analysis. The sample is then processed using a technology known as [[DNA microarray]] to obtain the genetic information.


==Types of tests==
==Types of tests==
There are three major types of genealogical DNA tests: [[Autosome|Autosomal]] (which includes X-DNA), Y-DNA, and mtDNA.
The most popular ancestry tests are Y chromosome (Y-DNA) testing and mitochondrial DNA (mtDNA) testing. Other tests attempt to determine a researcher's comprehensive genetic history and ethnic origins.
* '''Autosomal''' DNA tests look at chromosome pairs 1–22 and the X part of the 23rd chromosome. The autosomes (chromosome pairs 1–22) are inherited from both parents and all recent ancestors. The X-chromosome follows a special inheritance pattern, because females (XX) inherit an X-chromosome from each of their parents, while males (XY) inherit an X-chromosome from their mother and a Y-chromosome from their father (XY). Ethnicity estimates are often included with this sort of testing.
* '''Y-DNA''' looks at the Y-chromosome, which is passed down from father to son. Thus, the Y-DNA test can only be taken by males to explore their direct paternal line.
* '''mtDNA''' looks at the mitochondria, which is passed down from mother to child. Thus, the mtDNA test can be taken by both males and females, and it explores one's direct maternal line.<ref>{{harvtxt|Bettinger|Wayne|2016|p=8}}</ref>


Y-DNA and mtDNA cannot be used for ethnicity estimates, but can be used to find one's [[haplogroup]], which is unevenly distributed geographically.<ref name=":0">{{cite web|url=https://www.ucl.ac.uk/mace-lab/debunking/understanding-testing|title=Understanding genetic ancestry testing|date=2016|website=Molecular and Cultural Evolution Lab|publisher=University College London|access-date=2016-11-24|archive-url=https://web.archive.org/web/20160407010200/https://www.ucl.ac.uk/mace-lab/debunking/understanding-testing|archive-date=7 April 2016|url-status=dead}}</ref> Direct-to-consumer DNA test companies have often labeled [[Haplogroup|haplogroups]] by continent or ethnicity (e.g., an "African haplogroup" or a "Viking haplogroup"), but these labels may be speculative or misleading.<ref name=":0"/><ref>"Claims of connections, therefore, between specific uniparental lineages and historical figures or historical migrations of peoples are merely speculative." {{Cite journal|last2=Novembre|first2=John|last3=Fullerton|first3=Stephanie M.|last4=Goldstein|first4=David B.|last5=Long|first5=Jeffrey C.|last6=Bamshad|first6=Michael J.|last7=Clark|first7=Andrew G.|date=2010-05-14|title=Inferring Genetic Ancestry: Opportunities, Challenges, and Implications|journal=The American Journal of Human Genetics|volume=86|issue=5|pages=661–73|doi=10.1016/j.ajhg.2010.03.011|pmid=20466090|pmc=2869013|issn=0002-9297|last1=Royal|first1=Charmaine D.}}</ref><ref name=":2"/>
==Y chromosome (Y-DNA) testing==
A man's paternal ancestry can be traced using the DNA on his [[Y chromosome]] (Y-DNA). This is useful because the Y chromosome, like many European surnames, passes from father to son, and can be used to help study surnames.


===Autosomal DNA (atDNA) testing===<!--a redirect target for links from other articles-->
===What gets tested===
====Testing====
Y-DNA testing involves looking at segments of DNA on the Y chromosome (found only in males). Test results will be for a combination of [[short tandem repeat]]s (STRs) and/or [[single nucleotide polymorphism]]s (SNPs). These genetic markers occur in what is considered [[junk DNA|"junk" DNA]].
Autosomal DNA is contained in the 22 pairs of chromosomes not involved in determining a person's sex.<ref name=":0"/> Autosomal DNA recombines in each generation, and new offspring receive one set of chromosomes from each parent.<ref>{{harvtxt|Bettinger|Wayne|2016|p=70}}</ref> These are inherited exactly equally from both parents and roughly equally from grandparents to about 3x great-grandparents.<ref>{{harvtxt|Bettinger|Wayne|2016|p=68}}</ref> Therefore, the number of markers (one of two or more known variants in the [[genome]] at a particular location – known as [[Single-nucleotide polymorphism]]s or SNPs) inherited from a specific ancestor decreases by about half with each successive generation; that is, an individual receives half of their markers from each parent, about a quarter of those markers from each grandparent; about an eighth of those markers from each great-grandparent, etc. Inheritance is more random and unequal from more distant ancestors.<ref>{{Cite web|url=http://isogg.org/wiki/Autosomal_DNA|title=Autosomal DNA – ISOGG Wiki|website=isogg.org|access-date=2017-02-03}}</ref> Generally, a genealogical DNA test might test about 700,000 SNPs (specific points in the genome).<ref>{{cite web|url=https://www.smarterhobby.com/genealogy/best-dna-test/|title=Best Ancestry DNA Test 2018 – Which Testing Kit is Best & How to Choose|date=10 January 2018}}</ref>


[[File:Shared-cM-Relationship-Tree.jpg|thumb|right|250px|Shared DNA for different relatives]]
====STR markers====
[[short tandem repeat|STRs]] are changes to the number of times a segment of DNA which repeats. These repeating sets of nucleotides are referred to as [[genetic marker]]s and are designated by a [[DYS (DNA)|DYS number]] ('''D'''NA '''Y'''-chromosome '''S'''egment number).


====SNP markers====
====Reporting process====
The preparation of a report on the DNA in the sample proceeds in multiple stages:
[[single nucleotide polymorphism|SNPs]] are changes to a single nucleotide in a DNA sequence. The relative mutation rate for a SNP is extremely slow. This makes them ideal for marking the history of the human genetic tree. SNPs are named with a letter code and a number. The letter indicates the lab or research team that discovered the SNP. The number indicates the order in which it was discovered. For example M173 is the 173rd SNP documented by the group who uses the letter M.
* identification of the DNA base pair at specific SNP locations
* comparison with previously stored results
* interpretation of matches


=====Base pair identification=====
===Understanding test results===
All major service providers use equipment with chips supplied by [[Illumina (company)|Illumina]].<ref>{{cite web|url=https://dna-explained.com/2017/09/05/concepts-imputation/|title=Concepts – Imputation|date=5 September 2017}}</ref> The chip determines which SNP locations are tested. Different versions of the chip are used by different service providers. In addition, updated versions of the Illumina chip may test different sets of SNP locations. The list of SNP locations and base pairs at that location is usually available to the customer as "raw data". The raw data can be uploaded to some other genealogical service providers to produce an additional interpretation and matches. For additional genealogical analysis the data can also be uploaded to GEDmatch (a third-party web based set of tools that analyzes raw data from the main service providers). Raw data can also be uploaded to services that provide health risk and trait reports using SNP genotypes. These reports may be free or inexpensive, in contrast to reports provided by DTC testing companies, who charge about double the cost of their genealogy-only services. The implications of individual SNP results can be ascertained from raw data results by referring to SNPedia.com.
Commonly y-DNA tests test ten to sixty-seven STR markers on the Y chromosome but over one-hundred markers are available. SNP tests STR test results provide your personal haplotype. SNP results indicate your Haplogroup.


====Identification of Matches====
The major component of an autosomal DNA test is matching other individuals. Where the individual being tested has a number of consecutive SNPs in common with a previously tested individual in the company's database, it can be inferred that they share a segment of DNA at that part of their genomes.<ref>{{cite web|url=https://dna-explained.com/2016/03/|title=March – 2016 – DNAeXplained – Genetic Genealogy|website=dna-explained.com|date=30 March 2016 }}</ref> If the segment is longer than a threshold amount set by the testing company, then these two individuals are considered to be a match. Unlike the identification of base pairs, the data bases against which the new sample is tested, and the algorithms used to determine a match, are proprietary and specific to each company.


The unit for segments of DNA is the [[centimorgan]] (cM). For comparison, a full human genome is about 6500 cM. The shorter the length of a match, the greater are the chances that a match is spurious.<ref>{{cite web|url=http://thegeneticgenealogist.com/2017/01/06/the-danger-of-distant-matches/|title=The Danger of Distant Matches – The Genetic Genealogist|date=6 January 2017}}</ref> An important statistic for subsequent interpretation is the length of the shared DNA (or the percentage of the genome that is shared).
===Haplotype===
A Y-DNA [[haplotype]] is the numbered results of a genealogical Y-DNA test. Each [[allele]] value has a distinctive frequency within a population. For high resolution tests the [[allele]] frequencies provide a signature for a surname lineage.
{|class ="wikitable"
|-
! Kit || Surname || Haplo
|3<br>9<br>3<br><br>&nbsp;
|3<br>9<br>0<br><br>&nbsp;
|1<br>9<br> <br><br>&nbsp;
|3<br>9<br>1<br><br>&nbsp;
|3<br>8<br>5<br>a<br> <br>
|3<br>8<br>5<br>b<br> <br>
|4<br>2<br>6<br><br>&nbsp;
|3<br>8<br>8<br><br>&nbsp;
|4<br>3<br>9<br><br>&nbsp;
|3<br>8<br>9<br>-<br>1
|3<br>9<br>2<br><br>&nbsp;
|3<br>8<br>9<br>-<br>2
|4<br>5<br>8<br><br>&nbsp;
|4<br>5<br>9<br>a<br> <br>
|4<br>5<br>9<br>b<br> <br>
|4<br>5<br>5<br><br>&nbsp;
|4<br>5<br>4<br><br>&nbsp;
|4<br>4<br>7<br><br>&nbsp;
|4<br>3<br>7<br><br>&nbsp;
|4<br>4<br>8<br><br>&nbsp;
|4<br>4<br>9<br><br>&nbsp;
|4<br>6<br>4<br>a<br> <br>
|4<br>6<br>4<br>b<br> <br>
|4<br>6<br>4<br>c<br> <br>
|4<br>6<br>4<br>d<br> <br>
|-
| 11111 || Rumpelstiltskin || Q || 12 || 23 || 13 || 10 || 16 || 17 || 12 || 12 || 13 || 14 || 14 || 31 || 18 || 8 || 9 || 11 || 11 || 27 || 13 || 19 || 28 || 14 || 14 || 15 || 15
|}
The test results are then compared to another project member's results to determine the time frame in which the two people shared a [[most recent common ancestor]] (MRCA). If the two tests match on 37 markers, there is a 50% probability that the MRCA was fewer than 5 generations ago and a 90% probability that the MRCA was fewer than 17 generations ago.
{|class ="wikitable"
|-
! Kit || Surname || Haplo
|3<br>9<br>3<br><br>&nbsp;
|3<br>9<br>0<br><br>&nbsp;
|1<br>9<br> <br><br>&nbsp;
|3<br>9<br>1<br><br>&nbsp;
|3<br>8<br>5<br>a<br> <br>
|3<br>8<br>5<br>b<br> <br>
|4<br>2<br>6<br><br>&nbsp;
|3<br>8<br>8<br><br>&nbsp;
|4<br>3<br>9<br><br>&nbsp;
|3<br>8<br>9<br>-<br>1
|3<br>9<br>2<br><br>&nbsp;
|3<br>8<br>9<br>-<br>2
|4<br>5<br>8<br><br>&nbsp;
|4<br>5<br>9<br>a<br> <br>
|4<br>5<br>9<br>b<br> <br>
|4<br>5<br>5<br><br>&nbsp;
|4<br>5<br>4<br><br>&nbsp;
|4<br>4<br>7<br><br>&nbsp;
|4<br>3<br>7<br><br>&nbsp;
|4<br>4<br>8<br><br>&nbsp;
|4<br>4<br>9<br><br>&nbsp;
|4<br>6<br>4<br>a<br> <br>
|4<br>6<br>4<br>b<br> <br>
|4<br>6<br>4<br>c<br> <br>
|4<br>6<br>4<br>d<br> <br>
|-
| 11111 || Rumpelstiltskin || Q || 12 || 23 || 13 || 10 || 16 || 17 || 12 || 12 || 13 || 14 || 14 || 31 || 18 || 8 || 9 || 11 || 11 || 27 || 13 || 19 || 28 || 14 || 14 || 15 || 15
|-
| 11178 || Rumpelstiltskin || Q || 12 || 23 || 13 || 10 || 16 || 17 || 12 || 12 || 13 || 14 || 14 || 31 || 18 || 8 || 9 || 11 || 11 || 27 || 13 || 19 || 28 || 14 || 14 || 15 || 15
|}
It is important to check the number of markers that will be tested before choosing a test. For example, [[the Genographic Project]] only looks at 12 markers, while most laboratories and [[surname project]]s recommend testing at least 25. The more markers that are tested, the more discriminating and powerful the results will be. A 12 marker STR test is usually not discriminating enough to provide conclusive results for a common surname.
STRs results may also indicate a likely [[haplogroup]] for the Y chromosome, though this can only be confirmed by specifically testing for that Haplogroups' [[single nucleotide polymorphism]]s (SNPs). For example, at [[List of DYS markers|DYS455]], the results will show 8, 9, 10, 11 or 12 repeats<ref>[http://ybase.org/statistics.asp Ybase statistics]</ref>.


====Interpretation of Autosomal matches====
===Haplogroup===
Most companies will show the customers how many cMs they share and across how many segments. From the number of cMs and segments, the relationship between the two individuals can be estimated; however, due to the random nature of DNA inheritance, relationship estimates, especially for distant relatives, are only approximate. Some more distant cousins will not match at all.<ref>{{cite web|url=http://isogg.org/wiki/Cousin_statistics|title=Cousin statistics – ISOGG Wiki|website=isogg.org}}</ref> Although information about specific SNPs can be used for some purposes (e.g., suggesting likely eye color), the key information is the percentage of DNA shared by two individuals. This can indicate the closeness of the relationship. However, it does not show the roles of the two individuals, e.g., 50% shared suggests a parent/child relationship, but it does not identify which individual is the parent.
[[Haplogroup]]s are large groups of haplotypes that can be used to define genetic populations and are often geographically oriented. yDNA Haplogroups are determened by [[single nucleotide polymorphism|SNP]] tests.
{{Y-DNA}} These are locations on the DNA where one nucleotide has "mutated" or "switched" to a different nucleotide. The nucleotide switch must occur in at least 1% of the population to be considered a useful SNP. If it occurs in less than 1% of the population it is considered a personal SNP.


Various advanced techniques and analyses can be done on this data. This includes features such as In-common/Shared Matches,<ref>{{Cite news|url=https://www.familytreemagazine.com/premium/ancestry-dna-shared-matches-tutorial/|title=How to Use AncestryDNA Shared Matches – Family Tree|last=Combs-Bennett|first=Shannon|date=2015-12-03|work=Family Tree|access-date=2018-04-30}}</ref> Chromosome Browsers,<ref>{{Cite web|url=http://www.researchjournal.yourislandroutes.com/2018/03/myheritage-dna-ups-its-game-with-updated-chromosome-browser/|title=MyHeritage DNA Ups Its Game with Updated Chromosome Browser|last=Lassalle|first=Melody|date=2018-03-15|website=Genealogy Research Journal|access-date=2018-04-30}}</ref> and Triangulation.<ref>{{Cite news|url=https://www.familytreemagazine.com/premium/triple-play-dna-matches-triangulation/|title=Triple Play: Triangulating Your DNA Matches – Family Tree|last=Southard|first=Diahan|date=2017-06-19|work=Family Tree|access-date=2018-04-30}}</ref> This analysis is often required if DNA evidence is being used to prove or disprove a specific relationship.
====Haplogroup prediction====
A person's haplogroup can often be inferred from their haplotype, but can only be proven with a Y-chromosome SNP tests (Y-SNP test). In addition, some companies offer sub-clade tests, such as for [[Haplogroup G (Y-DNA)|Haplogroup G]].
For example, Haplogroup G has a known modal haplotype:
{| class="wikitable"
!DYS markers
|3<br>8<br>5<br>a
|3<br>8<br>5<br>b
|3<br>8<br>8<br>&nbsp;
|3<br>8<br>9<br>i
|3<br>8<br>9<br>ii
|3<br>9<br>0<br>&nbsp;
|3<br>9<br>1<br>&nbsp;
|3<br>9<br>2<br>&nbsp;
|3<br>9<br>3<br>&nbsp;
|3<br>9<br>4<br>&nbsp;
|4<br>2<br>6<br>&nbsp;
|4<br>3<br>7<br>&nbsp;
|4<br>3<br>9<br>&nbsp;
|4<br>4<br>7<br>&nbsp;
|4<br>4<br>8<br>&nbsp;
|4<br>4<br>9<br>&nbsp;
|4<br>5<br>4<br>&nbsp;
|4<br>5<br>5<br>&nbsp;
|4<br>5<br>8<br>&nbsp;
|4<br>5<br>9<br>a
|4<br>5<br>9<br>b
|4<br>6<br>4<br>a
|4<br>6<br>4<br>b
|4<br>6<br>4<br>c
|4<br>6<br>4<br>d
|-
!Haplogroup G: Modal STR values
|14
|14
|12
|12
|29
|22
|10
|11
|14
|15
|11
|16
|11
|23
|21
|31
|11
|11
|16
|9
|9
|12
|13
|13
|14
|}
Few haplotypes will exactly match the modal values for Haplogroup G. One can consult an [[allele frequency]] table to determine the likelihood of remaining in Haplogroup G based on the variations observed.
Additional predictions include:
*If DYS426 is 12 and DYS392 is 11, one is probably a member of haplogroup R1a1.
*If DYS426 is 12 and DYS392 is not 11, one is probably a member of haplogroup R1b.
*If DYS426 is 11, one is probably a member of haplogroup G,I, or J.
*If DYS426 is 11 and DYS388 is 12, one is probably a member of haplogroup N3 or E3b


==Mitochondrial DNA (mtDNA) testing==
===X-chromosome DNA testing===
The X-chromosome SNP results are often included in autosomal DNA tests. Both males and females receive an X-chromosome from their mother, but only females receive a second X-chromosome from their father.<ref>{{harvtxt|Bettinger|Wayne|2016|p=107}}</ref> The X-chromosome has a special path of inheritance patterns and can be useful in significantly narrowing down possible ancestor lines compared to autosomal DNA. For example, an X-chromosome match with a male can only have come from his maternal side.<ref>{{harvtxt|Bettinger|Wayne|2016|p=114}}</ref> Like autosomal DNA, X-chromosome DNA undergoes random recombination at each generation (except for father-to-daughter X-chromosomes, which are passed down unchanged). There are specialized inheritance charts which describe the possible patterns of X-chromosome DNA inheritance for males and females.<ref>{{harvtxt|Bettinger|Wayne|2016|p=111}}</ref>
[[Image:Map-of-human-migrations.jpg|thumb|right|268px|Map of human migration, according to Mitochondrial DNA. The numbers represent thousands of years before present time. The blue line represents the area covered in ice or tundra during the last great ice age. The North Pole is at the center. Africa, harboring the start of the migration, is at the top left and South America is at the far right.]]
A person's maternal ancestry can be traced using his or her [[Mitochondrial DNA]] (mtDNA). The DNA in the human [[Mitochondrial|mitochondria]] is passed down by the mother unchanged. One exception, which was linked to infertility, has been shown.


===What gets tested===
===STRs===
Some genealogical companies offer autosomal STRs (short tandem repeats).<ref name=":5">{{Cite journal|last1=Westen|first1=Antoinette A.|last2=Kraaijenbrink|first2=Thirsa|last3=Robles de Medina|first3=Elizaveta A.|last4=Harteveld|first4=Joyce|last5=Willemse|first5=Patricia|last6=Zuniga|first6=Sofia B.|last7=van der Gaag|first7=Kristiaan J.|last8=Weiler|first8=Natalie E.C.|last9=Warnaar|first9=Jeroen|date=May 2014|title=Comparing six commercial autosomal STR kits in a large Dutch population sample|journal=Forensic Science International: Genetics|volume=10|pages=55–63|doi=10.1016/j.fsigen.2014.01.008|pmid=24680126|doi-access=free}}</ref> These are similar to Y-DNA STRs. The number of STRs offered is limited, and results have been used for personal identification,<ref>{{Cite journal|last1=Ziętkiewicz|first1=Ewa|last2=Witt|first2=Magdalena|last3=Daca|first3=Patrycja|last4=Żebracka-Gala|first4=Jadwiga|last5=Goniewicz|first5=Mariusz|last6=Jarząb|first6=Barbara|last7=Witt|first7=Michał|date=2011-12-15|title=Current genetic methodologies in the identification of disaster victims and in forensic analysis|journal=Journal of Applied Genetics|volume=53|issue=1|pages=41–60|doi=10.1007/s13353-011-0068-7|issn=1234-1983|pmc=3265735|pmid=22002120}}</ref> paternity cases, and inter-population studies.<ref>{{Cite journal|last1=Sun|first1=Hao|last2=Zhou|first2=Chi|last3=Huang|first3=Xiaoqin|last4=Lin|first4=Keqin|last5=Shi|first5=Lei|last6=Yu|first6=Liang|last7=Liu|first7=Shuyuan|last8=Chu|first8=Jiayou|last9=Yang|first9=Zhaoqing|date=2013-04-08|editor-last=Caramelli|editor-first=David|title=Autosomal STRs Provide Genetic Evidence for the Hypothesis That Tai People Originate from Southern China|journal=PLOS ONE|volume=8|issue=4|pages=e60822|doi=10.1371/journal.pone.0060822|issn=1932-6203|pmc=3620166|pmid=23593317|bibcode=2013PLoSO...860822S|doi-access=free}}</ref><ref>{{Cite journal|last1=Guo|first1=Yuxin|last2=Chen|first2=Chong|last3=Xie|first3=Tong|last4=Cui|first4=Wei|last5=Meng|first5=Haotian|last6=Jin|first6=Xiaoye|last7=Zhu|first7=Bofeng|date=2018-06-13|title=Forensic efficiency estimate and phylogenetic analysis for Chinese Kyrgyz ethnic group revealed by a panel of 21 short tandem repeats|journal=Royal Society Open Science|volume=5|issue=6|pages=172089|doi=10.1098/rsos.172089|issn=2054-5703|pmc=6030347|pmid=30110484|bibcode=2018RSOS....572089G}}</ref>
mtDNA by current conventions is divided into three regions. They are the coding region and two [[Hyper Variable Region]]s (HVR1 and HVR2). All test results are compared to the mtDNA of a [[Europe|European]] in Haplogroup H2b. This sample is known as the [[Cambridge Reference Sequence]] (CRS). A list of [[single nucleotide polymorphism]]s (SNPs) is returned. Any "mutations" or "transitions" that are found are simply differences from the CRS.
The test results are compared to another person's results to determine the time frame in which the two people shared a most recent common ancestor (MRCA). The two most common mtDNA tests are a sequence of HVR1 and a sequence of both HVR1 and HVR2. Some people are now choosing to have a full sequence performed. This is still somewhat controversial as it may reveal medical information.


Law enforcement agencies in the US and Europe use autosomal STR data to identify criminals.<ref name=":5"/><ref>{{Cite journal|last=Norrgard|first=Karen|date=2008|title=Forensics, DNA Fingerprinting, and CODIS|url=https://www.nature.com/scitable/nated/article?action=showContentInPopup&contentPK=736|journal=Nature Education|volume=1|issue=1 |pages=35}}</ref>
===Understanding test results===
The most basic of mtDNA tests will sequence [[Hyper Variable Region]] 1 (HVR1). HVR1 [[nucleotide]]s are numbered 16001-16569. Some test reports might omit the 16 prefix from HVR1 results. ie 519C and not 16519C.


===Mitochondrial DNA (mtDNA) testing===<!--a redirect target for links from other articles-->
{| class="wikitable"
The [[mitochondrion]] is a component of a human cell, and contains its own DNA. Mitochondrial DNA usually has 16,569 base pairs (the number can vary slightly depending on addition or deletion mutations)<ref>{{harvtxt|Bettinger|Wayne|2016|p=9}}</ref> and is much smaller than the human genome DNA which has 3.2 billion base pairs. Mitochondrial DNA is transmitted from mother to child, as it is contained in the egg cell. Thus, a direct maternal ancestor can be traced using [[mtDNA]]. The transmission occurs with relatively rare mutations compared to autosomal DNA. A perfect match found to another person's mtDNA test results indicates shared ancestry of possibly between 1 and 50 generations ago.<ref name=":0"/> More distant matching to a specific haplogroup or subclade may be linked to a common geographic origin.
!Region

|HVR1
====Test====
|HVR2
The mtDNA, by current conventions, is divided into three regions. They are the coding region (00577-16023) and two [[Hyper Variable Region]]s (HVR1 [16024-16569], and HVR2 [00001-00576]).<ref>{{cite web|url=http://www.phylotree.org/rCRS_annotated.htm |title=mtDNA regions |work=Phylotree.org |access-date=2011-06-15 |url-status=dead |archive-url=https://web.archive.org/web/20110727174043/http://www.phylotree.org/rCRS_annotated.htm |archive-date=27 July 2011 }}</ref>
|-
!Differences from CRS
|111T,223T,259T,290T,319A,362C
| Not Tested
|}


The two most common mtDNA tests are a sequence of HVR1 and HVR2 and a full sequence of the mitochondria. Generally, testing only the HVRs has limited genealogical use so it is increasingly popular and accessible to have a full sequence. The full mtDNA sequence is only offered by Family Tree DNA among the major testing companies<ref name=":3">{{Cite web|url=https://www.top10dnatests.com/reviews/family-tree-dna-review/|title=Family Tree DNA Review|date=May 2018|website=Top 10 DNA Tests|access-date=2018-05-19}}</ref> and is somewhat controversial because the coding region DNA may reveal medical information about the test-taker<ref>{{harvtxt|Bettinger|Wayne|2016|p=50}}</ref>
More extensive tests will also sequence Hyper Variable Region 2 (HVR2). HVR2 nucleotides are numbered 073-577.


====Haplogroups====
[[File:Map-of-human-migrations.jpg|thumb|268px|Map of human migration [[Recent single origin hypothesis|out of Africa]], according to Mitochondrial DNA. The numbers represent thousands of years before present time. The blue line represents the area covered in ice or tundra during the last great ice age. The North Pole is at the center. Africa, the center of the start of the migration, is at the top left and South America is at the far right.]]
All humans descend in the direct female line from [[Mitochondrial Eve]], a female who lived probably around 150,000 years ago in Africa.<ref name=poz>{{cite journal |vauthors=Poznik GD, Henn BM, Yee MC, Sliwerska E, Euskirchen GM, Lin AA, Snyder M, Quintana-Murci L, Kidd JM, Underhill PA, Bustamante CD |title= Sequencing Y chromosomes resolves discrepancy in time to common ancestor of males versus females |journal= Science|volume= 341|issue=6145 |pages= 562–65 |date=August 2013|pmid=23908239|doi= 10.1126/science.1237619 |pmc=4032117|bibcode=2013Sci...341..562P}}</ref><ref name=Fu2013>{{cite journal|vauthors=Fu Q, Mittnik A, Johnson PL, Bos K, Lari M, Bollongino R, Sun C, Giemsch L, Schmitz R, Burger J, Ronchitelli AM, Martini F, Cremonesi RG, Svoboda J, Bauer P, Caramelli D, Castellano S, Reich D, Pääbo S, Krause J |title=A revised timescale for human evolution based on ancient mitochondrial genomes |journal=Current Biology |volume=23 |issue=7 |pages=553–59 |date=21 March 2013 |pmid=23523248 |doi=10.1016/j.cub.2013.02.044 |pmc=5036973|bibcode=2013CBio...23..553F }}</ref> Different branches of her descendants are different haplogroups. Most mtDNA results include a prediction or exact assertion of one's [[Human mitochondrial DNA haplogroups|mtDNA Haplogroup]]. Mitochrondial haplogroups were greatly popularized by the book ''[[The Seven Daughters of Eve]]'', which explores mitochondrial DNA.

====Understanding mtDNA test results====
It is not normal for test results to give a base-by-base list of results. Instead, results are normally compared to the [[Cambridge Reference Sequence]] (CRS), which is the mitochondria of a European who was the first person to have their mtDNA published in 1981 (and revised in 1999).<ref>{{harvtxt|Bettinger|Wayne|2016|p=51}}</ref> Differences between the CRS and testers are usually very few, thus it is more convenient than listing one's raw results for each base pair.

;Examples:
Note that in HVR1, instead of reporting the base pair exactly, for example 16,111, the 16 is often removed to give in this example 111. The letters refer to one of the four bases (A, T, G, C) that make up DNA.
{| class="wikitable"
{| class="wikitable"
|-
!Region
!Region
|HVR1
|HVR1
Line 194: Line 82:
!Differences from CRS
!Differences from CRS
|111T,223T,259T,290T,319A,362C
|111T,223T,259T,290T,319A,362C
|064T,073G,146C,153G
|073G,146C,153G
|}
|}


===Y-chromosome (Y-DNA) testing===<!--a redirect target for links from other articles-->
===Haplogroup===
The Y-chromosome is one of the 23rd pair of human chromosomes. Only males have a Y-chromosome, because women have two X chromosomes in their 23rd pair. A man's [[patrilineal]] ancestry, or male-line ancestry, can be traced using the DNA on his [[Y chromosome|Y-chromosome]] (Y-DNA), because the Y-chromosome is transmitted from a father to son nearly unchanged.<ref name=":1">{{harvtxt|Bettinger|Wayne|2016|p=30}}</ref> A man's test results are compared to another man's results to determine the time frame in which the two individuals shared a [[most recent common ancestor]], or MRCA, in their direct patrilineal lines. If their test results are very close, they are related within a genealogically useful time frame.<ref>{{cite web|url=http://www.smgf.org/pages/yinterpretation.jspx |title=Matching Y-Chromosome DNA Results| work=Molecular Genealogy| publisher=Sorenson Molecular Genealogy Foundation| access-date=2011-06-15 |url-status=live |archive-url=https://web.archive.org/web/20150503170935/http://www.smgf.org/pages/yinterpretation.jspx |archive-date=3 May 2015 }}</ref> A [[surname project]] is where many individuals whose Y-chromosomes match collaborate to find their common ancestry.
Most results include a prediction of mtDNA Haplogroup.
{{mtDNA}}
If you belong to a [[Human mitochondrial DNA haplogroups|Haplogroup]] that is distantly related to the CRS then the prediction may be sufficient. Some companies test for specific mutations in the coding region. For large Haplogroups such as mtDNA [[Haplogroup H (mtDNA)|Haplogroup H]] an extended test is offered to assign a sub-clade.


Women who wish to determine their direct paternal DNA ancestry can ask their father, brother, paternal uncle, paternal grandfather, or a paternal uncle's son (their cousin) to take a test for them.
==Ethnic tests==
Autosomal tests that test the recombining chromosomes are available. These attempt to measure an individual's mixed ethnic heritage. The tests' [[validity]] and [[Reliability (statistics)|reliability]] have been called into question but they continue to be popular.
===Biogeographical ancestry===
[[Autosome|Autosomal DNA]] testing purports to determine the "genetic percentage" of certain [[ethnicity|ethnicities]] in a person. These tests examine [[single nucleotide polymorphism|SNPs]], which are locations on the DNA where one nucleotide has "mutated" or "switched" to a different nucleotide. These tests are designed to tell what percentage [[Native Americans in the United States|Native American]], [[European]], [[East Asian]], and [[African]] a person is. These tests are controversial&mdash;their validity has not been independently confirmed — and the results are often disputed.


There are two types of DNA testing: STRs and SNPs.<ref name=":0"/>
One company<ref> AncestryByDNA <!--need to add link, http://www.ancestrybydna.com this one?--></ref> describes these four ethnic groups as follows:
*Native American: Populations that migrated from Asia to inhabit North, South and Central America.
*European: European, Middle Eastern and South Asian populations from the Indian subcontinent, including India, Pakistan and Sri Lanka.
*East Asian: Japanese, Chinese, Mongolian, Korean, Southeast Asian and Pacific Islander populations, including populations native to the Philippines.
*African: Populations from Sub-Saharan Africa such as Nigeria and Congo region.


====STR markers====
A personal genetic analysis can be performed by one company<ref>http://www.dnatribes.com/</ref> that identifies the indigenous and diaspora populations in which an individual's autosomal STR profile is most common. This test examines autosomal [[short tandem repeat|STRs]], which are locations on a chromosome where a pattern of two or more nucleotides is repeated and the repetitions are directly adjacent to each other. The populations in which the individual's profile is most common are identified and assigned a likelihood score. The individual's profile is assigned a likelihood of membership in each of twenty three world regions:
Most common is [[Y-STR|STRs]] (short tandem repeat). A certain section of DNA is examined for a pattern that repeats (e.g. ATCG). The number of times it repeats is the value of the marker. Typical tests test between 12 and 111 STR markers. STRs mutate fairly frequently. The results of two individuals are then compared to see if there is a match. DNA companies will usually provide an estimate of how closely related two people are, in terms of generations or years, based on the difference between their results.<ref>{{harvtxt|Bettinger|Wayne|2016|p=35}}</ref>


====SNP markers and Haplogroups====
* Alaskan: Inuit peoples of Alaska.
[[File:dna-SNP.svg|thumb|250px|Strand 1 differs from strand 2 at a single base pair location (a C → T polymorphism).]]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).
* Athabaskan: Athabaskan speaking peoples of Western North America.
* Northeast Amerindian: Native peoples of Northeastern North America.
* Salishan: Salish speaking peoples of the American Pacific Northwest.
* South Amerindian: Native peoples of South America.
* Mestizo (“mixed”): Native Americans blended with Europeans and Africans.


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.<ref>{{harvtxt|Bettinger|Wayne|2016|p=41}}</ref> 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.
* Arabian: The Arabian Peninsula.
* Asia Minor: The East Mediterranean and Anatolia to the Tarim Basin.
* North African: North Africa.
* North Indian: Northern India.
* South Indian: Southern India.
* Sub-Saharan African: Africa south of the Sahara Desert.


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.<ref name="bottleneck">{{cite journal | last1 = Karmin |display-authors=etal | year = 2015 | title = A recent bottleneck of Y chromosome diversity coincides with a global change in culture |journal=[[Genome Research]] | volume = 25| issue = 4| pages = 459–66| doi = 10.1101/gr.186684.114 | pmid=25770088 | pmc=4381518}} "we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192–307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47–52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky."</ref><ref name="Mendez2016">{{cite journal | last1 = Mendez | first1 = L. |display-authors=etal | year = 2016 | title = The Divergence of Neandertal and Modern Human Y Chromosomes | doi = 10.1016/j.ajhg.2016.02.023 | journal = The American Journal of Human Genetics | volume = 98 | issue = 4| pages = 728–34 | pmid=27058445 | pmc=4833433}}</ref> 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).<ref>{{harvtxt|Bettinger|Wayne|2016|p=40}}</ref>
* Eastern European: The Slavic speaking region of Eastern Europe.
* Basque: The Basque speaking peoples of Western Europe.
* Finno-Ugrian: The Uralic speaking region of Northeastern Europe.
* Mediterranean: The Romance speaking region of Southern Europe.
* Northwest European: The Celtic and Germanic speaking region of Northwestern Europe.


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 A (Y-DNA)#A00-AF6|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.
* Australian: Aboriginal peoples of Australia.
* Chinese: The Chinese region of East Asia.
* Japanese: The Japanese Archipelago.
* Polynesian: The Polynesian Islands.
* Southeast Asian: Southeast Asia and the Malay Archipelago.
* Tibetan: The Himalayas and Tibetan Plateau.


===Using DNA test results===
This STR analysis measures the frequency of a person's DNA profile within major world regions. Unlike SNP admixture tests, this analysis is based on objectively identified world regions and does not depend on any system of presumed racial classifications.
{{Main|Genetic genealogy}}


===Native American ancestry===
====Ethnicity estimates====
Many companies offer a percentage breakdown by ethnicity or region. Generally the world is specified into about 20–25 regions, and the approximate percentage of DNA inherited from each is stated. This is usually done by comparing the frequency of each [[Autosome|Autosomal DNA]] marker tested to many population groups.<ref name=":0"/> The reliability of this type of test is dependent on comparative population size, the number of markers tested, the ancestry informative value of the SNPs tested, and the degree of admixture in the person tested. Earlier ethnicity estimates were often wildly inaccurate, but as companies receive more samples over time, ethnicity estimates have become more accurate. Testing companies such as [[Ancestry.com]] will often regularly update their ethnicity estimates, which has caused some controversy from customers as their results update.<ref>{{Cite web|url=https://www.nydailynews.com/news/national/ny-ancestry-update-to-dna-results-confuses-upsets-customers-20190429-cce6vv7ilvcb5dvquuxkv3iia4-story.html|title=Ancestry.com update changes ethnicity of customers|last=Alsup|first=Blake|date=29 April 2019|website=NY Daily News}}</ref><ref>{{Cite web|url=https://www.king5.com/article/news/nation-now/ancestrycom-changed-how-it-determines-ethnicity-and-people-are-upset/465-f0205386-1e13-4c92-899b-d2a92dfe698f|title=Ancestry.com changed how it determines ethnicity and people are upset|last=Daalder|first=Marc|date=18 September 2018|website=K5 News|access-date=11 June 2019|archive-date=30 September 2022|archive-url=https://web.archive.org/web/20220930014458/https://www.king5.com/article/news/nation-now/ancestrycom-changed-how-it-determines-ethnicity-and-people-are-upset/465-f0205386-1e13-4c92-899b-d2a92dfe698f|url-status=dead}}</ref> Usually the results at the continental level are accurate, but more specific assertions of the test may turn out to be incorrect.{{cn|date=December 2023}}
Autosomal testing, Y-DNA, and mtDNA testing can also be conducted to determine Native American ancestry. A mitochondrial haplogroup determination test based on mutations in [[Hypervariable Region]] I + II may establish whether a person's direct female line belongs to one of the five recognized Native American haplogroups, [[Haplogroup A (mtDNA)|A]], [[Haplogroup B (mtDNA)|B]], [[Haplogroup C (mtDNA)|C]], [[Haplogroup D (mtDNA)|D]] or [[Haplogroup X (mtDNA)|X]], with the inference that he or she is, in whole or part, Native American. Comparisons with tribal-specific haplotypes of the sort published by geneticists Ripan Malhi and Jason Eschleman of Trace Genetics[http://www.tracegenetics.com] can further suggest tribal affiliation, though no federally-recognized tribe considers DNA as admissible evidence for enrollment. This is based rather on the demonstrable appearance of names of one's direct ancestors on tribal-specific Native American censuses prepared as the fallout of [[treaty]] making and relegation to reservations in the nineteenth century. Complicating factors are the Native American name controversy and recent evidence that indigenous North American [[Human mitochondrial DNA haplogroups|mitochondrial haplogroups]] are not limited to the five named. Many Americans are just discovering their Native roots, however, and the small chance of belonging to one of the acknowledged lineages, particularly in the case of male lines, which were almost entirely eradicated by the process of history, does not deter some from attempting to validate their heritage with the goal of gaining admittance into a tribe. These tests, moreover, are ideal for adoptees with Native American blood, of which there are now many in U.S. and Canadian society because of past policies of assimilation.


==Audience==
===African ancestry===
The interest in genealogical DNA tests has been linked to both an increase in curiosity about traditional genealogy and to more general personal origins. Those who test for traditional genealogy often utilize a combination of autosomal, mitochondrial, and Y-Chromosome tests. Those with an interest in personal ethnic origins are more likely to use an autosomal test. However, answering specific questions about the ethnic origins of a particular lineage may be best suited to an mtDNA test or a Y-DNA test.
African Ancestry offers Y-DNA and mtDNA testing to determine with which present-day [[Africa]]n country the direct-line paternal lineage or direct-line maternal lineage shares its ancestry. A pioneer in this field is Rick Kittles, a co-director of the [[National Human Genome Research Institute]]. It is estimated that 30 percent of African American males have a European [[Human Y-chromosome DNA haplogroup|Y chromosome haplogroup]]. As for the mitochondrial haplotypes, [[African Ancestry (company)|African Ancestry]], Kittles' Washington, D.C.-based company specializing in such tests, lists some 300 tribal affiliations and seeks to assign, within a certain measure of likelihood, an African tribe to testees. Thus, [[Oprah Winfrey]], the television talk show host, announced that she had discovered her [[Zulu]] roots. Zulu heritage from southern Africa must be counted as extremely rare, however, since according to authorities like Salas, nearly three-quarters of the ancestors of African Americans taken in [[History of slavery in the United States|slavery]] came from West Africa and most of these were Bantu. The African American [[tribal]] movement, however, has burgeoned since DNA testing, with members of African American churches taking the test as groups. One reason is that owing to slavery, African Americans cannot easily trace their ancestry through surname research, census and property records and other traditional means.
===Cohanim ancestry===
{{Main|Y-chromosomal Aaron}}
The [[Kohen|Cohanim]] (or Kohanim) is a [[Patrilineality|patrilineal]] priestly line of descent in [[Judaism]]. According to the [[Torah|Bible]] the ancestor of the Cohanim is [[Aaron]], brother of [[Moses]]. Many believe that descent from Aaron is verifiable with a Y-DNA test. The set of markers which determine Cohanim ancestry are known as the [[Cohen Modal Haplotype]]. This hypothetical ancestor of the Cohanim is called [[Y-chromosomal Aaron]].


===Maternal origin tests===
The whole field of Y chromosome DNA testing began with a Canadian doctor's discovery that an overwhelming majority of Jewish males with the surname [[Kohen|Cohen]] (Hebrew for “priest”) had the same, or approximately the same set of markers, suggesting they truly descended from an original founder-priest like Aaron.
For recent genealogy, exact matching on the mtDNA full sequence is used to confirm a common ancestor on the direct maternal line between two suspected relatives. Because mtDNA mutations are very rare, a ''nearly'' perfect match is not usually considered relevant to the most recent 1 to 16 generations.<ref>{{cite web |url=http://www.smgf.org/pages/mt_interpretation.jspx |title=mtDNA matches |work=Smgf.org |access-date=2011-06-15 |archive-url=https://web.archive.org/web/20081118135732/http://www.smgf.org./pages/mt_interpretation.jspx |archive-date=18 November 2008 |url-status=dead }}</ref> In cultures lacking [[matrilineal surnames]] to pass down, neither relative above is likely to have as many generations of ancestors in their matrilineal information table as in the above patrilineal or Y-DNA case: for further information on this difficulty in ''traditional genealogy'', due to lack of ''matrilineal'' surnames (or matrinames), see [[Matriname]].<ref name=Sykes>Sykes, Bryan (2001). ''The Seven Daughters of Eve''. W. W. Norton. {{ISBN|0-393-02018-5}}, pp. 291–92. Sykes discusses the difficulty in genealogically tracing a maternal lineage, due to the lack of matrilineal surnames (or matrinames).</ref> However, the foundation of testing is still two suspected descendants of one person. This hypothesize and test DNA pattern is the same one used for autosomal DNA and Y-DNA.


===Tests for ethnicity and membership of other groups===
===European testing===
[[File:European genetic structure (based on SNPs) PC analysis.png|thumb|European genetic structure (based on Autosomal SNPs) by [[Principal component analysis|PCA]]]]
As discussed above, autosomal tests usually report the ethnic proportions of the individual. These attempt to measure an individual's mixed geographic heritage by identifying particular markers, called ancestry informative markers or AIM, that are associated with populations of specific geographical areas. Geneticist [[Adam Rutherford]] has written that these tests "don’t necessarily show your geographical origins in the past. They show with whom you have common ancestry today."<ref name="Charlemagne">{{cite news|last1=Rutherford|first1=Adam|title=So you're related to Charlemagne? You and every other living European…|url=https://www.theguardian.com/science/commentisfree/2015/may/24/business-genetic-ancestry-charlemagne-adam-rutherford|access-date=8 February 2016|newspaper=The Guardian|date=24 May 2015}}</ref>
====European maternal clan testing====
For people with European maternal ancestry, mtDNA tests are offered to determine which of eight European maternal "clans" the direct-line maternal ancestor belonged to. This is simply an mtDNA haplotype test based on the research in the book ''[[The Seven Daughters of Eve]]''.
====Sub-European population testing====
SNP testing may enable mostly-European individuals to determine to which Sub-European population they belong:
*Northern European subgroup (NOR) - mostly Northern European or Irish
*Southeastern European (Mediterranean) subgroup (MED) - mostly Southeastern Europeans (Greeks or Turks)
*Middle Eastern subgroup (MIDEAS) - mostly Middle Eastern
*South Asian subgroup (SA) - mostly South Asian from the Indian sub-continent (i.e. Indian)


The haplogroups determined by Y-DNA and mtDNA tests are often unevenly geographically distributed. Many direct-to-consumer DNA tests described this association to infer the test-taker's ancestral homeland.<ref name=":2">{{Cite journal|last2=Magnaye|first2=Kevin M.|last3=Bigham|first3=Abigail W.|last4=Akey|first4=Joshua M.|last5=Bamshad|first5=Michael J.|date=2015-02-05|title=Estimates of Continental Ancestry Vary Widely among Individuals with the Same mtDNA Haplogroup|journal=The American Journal of Human Genetics|volume=96|issue=2|pages=183–93|doi=10.1016/j.ajhg.2014.12.015|pmid=25620206|pmc=4320259|issn=0002-9297|last1=Emery|first1=Leslie S.}}</ref> Most tests describe haplogroups according to their most frequently associated continent (e.g., a "European haplogroup").<ref name=":2"/> When Leslie Emery and collaborators performed a trial of mtDNA haplogroups as a predictor of continental origin on individuals in the Human Genetic Diversity Panel (HGDP) and 1000 Genomes (1KGP) datasets, they found that only 14 of 23 haplogroups had a success rate above 50% among the HGDP samples, as did "about half" of the haplogroups in the 1KGP.<ref name=":2"/> The authors concluded that, for most people, "mtDNA-haplogroup membership provides limited information about either continental ancestry or continental region of origin."<ref name=":2"/>
===Hindu testing===
One company uses a 37-marker Y-DNA test which it says can be used to "verify genetic relatedness and historical [[gotra]] genealogies for [[Hindu]] and [[Buddhist]] engagements, marriages and business partnerships." Gotras are clans or families whose members trace their descent to a common ancestor, usually a sage of ancient times. The gotra proclaims a person's identity and a "gotraspeak" is required to be presented at Hindu ceremonies. People of the same gotra are not allowed to marry. There are 49 established gotras.


===Melungeon testing===
====African ancestry====
Y-DNA and mtDNA testing may be able to determine with which peoples in present-day [[Africa]] a person shares a direct line of part of his or her ancestry, but patterns of historic migration and historical events cloud the tracing of ancestral groups. Due to joint long histories in the US, approximately 30% of [[African American]] males have a European [[Human Y-chromosome DNA haplogroup|Y-Chromosome haplogroup]]<ref>{{cite web|url=http://www.africanancestry.com/patriclan.html |title=Patriclan: Trace Your Paternal Ancestry |publisher=African Ancestry |access-date=2011-06-15 |url-status=dead |archive-url=https://web.archive.org/web/20110707092826/http://www.africanancestry.com/patriclan.html |archive-date=7 July 2011 }}</ref> Approximately 58% of African Americans have at least the equivalent of one great-grandparent (13%) of European ancestry. Only about 5% have the equivalent of one great-grandparent of Native American ancestry. By the early 19th century, substantial families of Free Persons of Color had been established in the [[Chesapeake Bay]] area who were descended from free people during the colonial period; most of those have been documented as descended from white men and African women (servant, slave or free). Over time various groups married more within mixed-race, black or white communities.<ref>Paul Heinegg, ''Free African Americans of Virginia, North Carolina, South Carolina, Maryland and Delaware''[http://www.freeafricanamericans.com/], accessed 15 February 2008</ref>
{{main|Melungeon#DNA testing}}
Several efforts, including a number of ongoing studies, have examined the genetic makeup of families historically identified as Melungeon. Most results point to a mixture of European, African, and Native American lineages.


According to authorities like Salas, nearly three-quarters of the ancestors of African Americans taken in [[History of slavery in the United States|slavery]] came from regions of West Africa. The African-American movement to discover and identify with ancestral tribes has burgeoned since DNA testing became available. African Americans usually cannot easily trace their ancestry during the years of slavery through [[Surname project|surname research]], [[census]] and property records, and other traditional means. Genealogical DNA testing may provide a tie to regional African heritage.
==Benefits==
{{main|Genetic genealogy}}
Genealogical DNA tests have become popular due to the ease of testing at home and the various additions they make to [[genealogy|genealogical research]]. Genealogical DNA tests allow for an individual to determine with 99.9% certainty that he or she is related to another person within a certain time frame, or with 100% certainty that he or she is not related. DNA tests are perceived as more scientific, conclusive and expeditious.


====United States – Melungeon testing====
==Drawbacks==
{{Main|Melungeon DNA Project}}
Y-DNA and mtDNA testing each only trace a single lineage (one's father's father's father's etc. lineage or one's mother's mother's mother's etc. lineage). At 10 generations back, an individual has 1024 ancestors (excluding intermarriages) and a Y-DNA or mtDNA test is only studying one of those 1024 ancestors. However, families in the past married in-group and breeding pools were typically small, so the paternal line can be diagnostic of additional ancestry.
[[Melungeon]]s are one of numerous multiracial groups in the United States with origins wrapped in myth. The historical research of Paul Heinegg has documented that many of the Melungeon groups in the Upper South were descended from mixed-race people who were free in colonial Virginia and the result of unions between the Europeans and Africans. They moved to the frontiers of Virginia, North Carolina, Kentucky and Tennessee to gain some freedom from the racial barriers of the plantation areas.<ref>[http://www.freeafricanamericans.com Paul Heinegg, ''Free African Americans of Virginia, North Carolina, South Carolina, Maryland and Delaware''], accessed 15 February 2008</ref> Several efforts, including a number of ongoing studies, have examined the genetic makeup of families historically identified as Melungeon. Most results point primarily to a mixture of European and African, which is supported by historical documentation. Some may have Native American heritage as well. Though some companies provide additional Melungeon research materials with Y-DNA and mtDNA tests, any test will allow comparisons with the results of current and past Melungeon DNA studies.


====Native American ancestry====
The most common complaint from DNA test customers is failure of the company to make results understandable and meaningful to them. This was the No. 1 reason cited for customer dissatisfaction in a June 2006 nationwide telephone survey conducted by Shapiro and Associates. According to an earlier survey, 1 in 6 Americans (18%) said they were aware of the ancestry-tracing capability of a home DNA test but when probed, most knew little about the details, reliability or differences between tests.
{{Further|Genetic history of indigenous peoples of the Americas}}
The [[pre-columbian]] indigenous people of the United States are called "Native Americans" in American English.<ref>{{cite web|url=http://www.merriam-webster.com/dictionary/native%2520american|title=Native American {{!}} Definition of Native American by Merriam-Webster|website=www.merriam-webster.com|access-date=2016-10-04}}</ref> Autosomal testing, Y-DNA, and mtDNA testing can be conducted to determine the ancestry of [[Native Americans in the United States|Native Americans]]. A mitochondrial Haplogroup determination test based on mutations in [[Hypervariable Region]] 1 and 2 may establish whether a person's direct female line belongs to one of the canonical Native American Haplogroups, [[Haplogroup A (mtDNA)|A]], [[Haplogroup B (mtDNA)|B]], [[Haplogroup C (mtDNA)|C]], [[Haplogroup D (mtDNA)|D]] or [[Haplogroup X (mtDNA)|X]]. The vast majority of Native American individuals belong to one of the five identified [[mtDNA]] [[Haplogroup]]s. Thus, being in one of those groups provides evidence of potential Native American descent. However, DNA ethnicity results cannot be used as a substitute for legal documentation.<ref>{{cite web|url=https://www.ancestry.co.uk/dna/legal/faq|title=AncestryDNA FAQ|website=www.ancestry.co.uk}}</ref> [[Tribe (Native American)|Native American tribes]] have their own requirements for membership, often based on at least one of a person's ancestors having been included on tribal-specific Native American censuses (or final rolls) prepared during [[treaty]]-making, relocation to [[Indian reservation|reservations]] or apportionment of land in the late 19th century and early 20th century. One example is the [[Dawes Rolls]].


====Cohanim ancestry====
A further drawback, at least with autosomal tests is their present state of imperfection and large margin of error (up to 15%, according to some genomics experts), with significant blind spots such as confusion of Mongolian ancestry with Native American.
{{Main|Y-chromosomal Aaron}}
The [[Kohen|Cohanim]] (or Kohanim) is a [[Patrilineality|patrilineal]] priestly line of descent in [[Judaism]]. According to the [[Torah|Bible]], the ancestor of the Cohanim is [[Aaron]], brother of [[Moses]]. Many believe that descent from Aaron is verifiable with a Y-DNA test: the first published study in genealogical Y-Chromosome DNA testing found that a significant percentage of Cohens had distinctively similar DNA, rather more so than general Jewish or Middle Eastern populations. These Cohens tended to belong to [[Haplogroup J (Y-DNA)|Haplogroup J]], with Y-STR values clustered unusually closely around a haplotype known as the [[Cohen Modal Haplotype]] (CMH). This could be consistent with a shared common ancestor, or with the hereditary priesthood having originally been founded from members of a single closely related clan.


Nevertheless, the original studies tested only six Y-STR markers, which is considered a low-resolution test. In response to the low resolution of the original 6-marker CMH, the testing company FTDNA released a 12-marker CMH signature that was more specific to the large closely related group of Cohens in Haplogroup J1.
==Medical information==
Though genealogical DNA tests results generally have no informative medical value and do not determine genetic diseases or disorders, there has been a correlation established between a lack of [[List of DYS markers#DYS464|DYS464]] markers and [[infertility]], and a correlation between [[Haplogroup H (mtDNA)|mtDNA haplogroup H]] and protection from [[sepsis]]. Certain haplogroups have been linked to longevity. A more [[genetic testing|specific test]] is used for medical purposes, which focuses on a particular gene or set of genes. The field of linkage disequilibrium, unequal association of genetic disorders with a certain mitochondrial lineage, is in its infancy, but those mitochondrial mutations that have been linked are searchable in the genome database [http://www.mitomap.org Mitomap]. The National Human Genome Research Institute operates a [http://www.genome.gov/10000409 Genetic And Rare Disease Information Center (GARD)] that can assist consumers in identifying an appropriate screening test and help locate a nearby medical center that offers such.


A further academic study published in 2009 examined more STR markers and identified a more sharply defined SNP haplogroup, [[Haplogroup J1e (Y-DNA)|J1e*]] (now J1c3, also called J-P58*) for the J1 lineage. The research found "that 46.1% of Kohanim carry Y chromosomes belonging to a single paternal lineage (J-P58*) that likely originated in the Near East well before the dispersal of Jewish groups in the Diaspora. Support for a Near Eastern origin of this lineage comes from its high frequency in our sample of [[Bedouins]], Yemenis (67%), and Jordanians (55%) and its precipitous drop in frequency as one moves away from Saudi Arabia and the Near East (Fig. 4). Moreover, there is a striking contrast between the relatively high frequency of J-58* in Jewish populations (»20%) and Kohanim (»46%) and its vanishingly low frequency in our sample of non-Jewish populations that hosted Jewish diaspora communities outside of the Near East."<ref name="Hammer2009">{{cite journal | vauthors = Hammer MF, Behar DM, Karafet TM, Mendez FL, Hallmark B, Erez T, Zhivotovsky LA, Rosset S, Skorecki K | title = Extended Y chromosome haplotypes resolve multiple and unique lineages of the Jewish priesthood | journal = Human Genetics | volume = 126 | issue = 5 | pages = 707–17 | date = November 2009 | pmid = 19669163 | pmc = 2771134 | doi = 10.1007/s00439-009-0727-5 }}</ref>
==References and recommended readings==
<div class="references-small">
<references />
Carmichael, Terrence and Alexander Kuklin (2000). ''How to DNA Test Our Family Relationships.'' DNA Press. Early (and still unique) book on adoptions, paternity and other relationship testing. Carmichael is a founder of GeneTree.


Recent phylogenetic research for haplogroup J-M267 placed the "Y-chromosomal Aaron" in a subhaplogroup of J-L862, L147.1 (age estimate 5631-6778yBP yBP): YSC235>PF4847/CTS11741>YSC234>ZS241>ZS227>Z18271 (age estimate 2731yBP).<ref name=Mas2014>{{cite book | last1 = Mas | first1 = V. | year = 2013 | title = Y-DNA Haplogroup J1 phylogenetic tree | publisher = Figshare| doi = 10.6084/m9.figshare.741212}}</ref>
Cavalli-Sforza, L. et al (1994). ''The History and Geography of Human Genes.'' Princeton: Princeton University Press. Dense but very comprehensiven.


====European testing====
Cavalli-Sforza, Luigi-Luca and Francesco (1998). ''The Great Human Diasporas, translated from the Italian by Sarah Thorne.'' Reading, Mass. : Perseus Books. More readable than the Stanford professor’s other books.
{{Further|Genetic history of Europe}}


==Benefits==
Family Tree Magazine. Leading non-specialist genealogy magazine, reviews genetic genealogy products and companies from time to time.
{{Main|Genetic genealogy}}
Genealogical DNA tests have become popular due to the ease of testing at home and their usefulness in supplementing [[genealogy|genealogical research]]. Genealogical DNA tests allow for an individual to determine with high accuracy whether he or she is related to another person within a certain time frame, or with certainty that he or she is not related. DNA tests are perceived as more scientific, conclusive and expeditious than searching the civil records. However, they are limited by restrictions on lines that may be studied. The civil records are always only as accurate as the individuals having provided or written the information.


[[Y-DNA testing]] results are normally stated as probabilities: For example, with the same surname a perfect 37/37 marker test match gives a 95% likelihood of the most recent common ancestor (MRCA) being within 8 generations,<ref>ftdna.com (kept uptodate). http://www.familytreedna.com/faq/answers/default.aspx?faqid=9#922 "FAQ: ...how should the genetic distance at 37 Y-chromosome STR markers be interpreted?" Retrieved 2012-01-13.</ref> while a 111 of 111 marker match gives the same 95% likelihood of the MRCA being within only 5 generations back.<ref name=match111>ftdna.com (kept uptodate). http://www.familytreedna.com/faq/answers/default.aspx?faqid=9#925 "FAQ: ...how should the genetic distance at 111 Y-chromosome STR markers be interpreted?" Retrieved 2012-01-13.</ref>
Fitzpatrick, Colleen and Andrew Yeiser (2005). ''DNA and Genealogy.'' Rice Book Press. Highly regarded commentary on news stories about DNA and how-to introduction for laymen.


As presented above in [[mtDNA testing]], if a perfect match is found, the mtDNA test results can be helpful. In some cases, research according to traditional genealogy methods encounters difficulties due to the lack of regularly recorded matrilineal surname information in many cultures (see [[Matrilineal surname]]).<ref name=Sykes/>
Gamble, Clive (1993). ''Timewalkers: The Prehistory of Global Colonization.'' Stroud: Sutton. Popular account of human prehistory by British anthropologist/archeologist. Article from American Scientist.


Autosomal DNA combined with genealogical research has been used by adoptees to find their biological parents,<ref>{{Cite news|url=https://www.deseretnews.com/article/865667270/Adopted-man-finds-biological-family-with-help-of-AncestryDNA.html|archive-url=https://web.archive.org/web/20161117151540/http://www.deseretnews.com/article/865667270/Adopted-man-finds-biological-family-with-help-of-AncestryDNA.html|url-status=dead|archive-date=17 November 2016|title=Adopted man finds biological family with help of AncestryDNA|last=Randall|first=Caresa Alexander|date=2016-11-16|work=Deseret News|access-date=2018-04-30}}</ref> has been used to find the name and family of unidentified bodies<ref>{{Cite news|url=https://www.cbsnews.com/news/buckskin-girl-case-groundbreaking-dna-tech-leads-to-id-of-1981-murder-victim/|title="Buckskin Girl" case: DNA breakthrough leads to ID of 1981 murder victim|date=2018-03-12|work=CBS News|access-date=2018-04-30}}</ref><ref>{{Cite news|url=https://www.forensicmag.com/news/2018/05/dna-doe-project-ids-2001-motel-suicide-using-genealogy|title=DNA Doe Project IDs 2001 Motel Suicide, Using Genealogy|last=Augenstein|first=Seth|date=2018-05-09|work=Forensic Magazine|access-date=2018-05-19}}</ref> and by law enforcement agencies to apprehend criminals<ref>{{Cite news|url=https://www.theatlantic.com/science/archive/2018/04/golden-state-killer-east-area-rapist-dna-genealogy/559070/|title=How a Genealogy Website Led to the Alleged Golden State Killer|last=Zhang|first=Sarah|date=2018-03-27|work=The Atlantic|access-date=2018-04-30}}</ref><ref>{{Cite news|url=https://www.seattletimes.com/seattle-news/crime/investigators-use-dna-genealogy-database-to-id-suspect-in-1987-double-homicide/|title=Investigators use DNA, genealogy database to ID suspect in 1987 double homicide|last=Green|first=Sara Jean|date=2018-05-18|work=The Seattle Times|access-date=2018-05-19}}</ref> (for example, the [[Contra Costa County, California|Contra Costa County]] District Attorney's office used the "open-source" genetic genealogy site [[GEDmatch]] to find relatives of the suspect in the [[Golden State Killer]] case.<ref>{{cite web|url=https://www.technologyreview.com/s/611038/investigators-searched-a-million-peoples-dna-to-find-golden-state-serial-killer/|title=Investigators searched a million people's DNA to find Golden State serial killer|last=Regalado|first=Antonio}}</ref><ref>{{cite news|url=http://www.sacbee.com/news/local/crime/article209987599.html|title='Open-source' genealogy site provided missing DNA link to East Area Rapist, investigator says|last1=Lillis|first1=Ryan|date=27 April 2018|work=[[The Sacramento Bee]]|access-date=27 April 2018|last2=Kasler|first2=Dale|last3=Chabria|first3=Anita}}</ref>). [[The Atlantic]] magazine commented in 2018 that "Now, the floodgates are open. ..a small, volunteer-run website, GEDmatch.com, has become ... the de facto DNA and genealogy database for all of law enforcement."<ref>{{Cite news|url=https://www.theatlantic.com/science/archive/2018/05/the-coming-wave-of-murders-solved-by-genealogy/560750/|title=The Coming Wave of Murders Solved by Genealogy|last=Zhang|first=Sarah|date=2018-05-19|work=The Atlantic|access-date=2018-05-19}}</ref> Family Tree DNA announced in February 2019 it was allowing the FBI to access its DNA data for cases of murder and rape.<ref>{{Cite news|url=https://www.nytimes.com/2019/02/04/business/family-tree-dna-fbi.html|title=FamilyTreeDNA Admits to Sharing Genetic Data With F.B.I.|last=Haag|first=Matthew|date=2019-02-04|work=The New York Times|access-date=2019-04-10|issn=0362-4331}}</ref> However, in May 2019 GEDmatch initiated stricter rules for accessing their autosomal DNA database<ref>{{Cite web|url=https://www.forensicmag.com/news/2019/05/forensic-genealogy-where-does-cold-case-breakthrough-technique-go-after-gedmatch-announcement|title=Forensic Genealogy: Where Does Cold-Case Breakthrough Technique Go After GEDmatch Announcement?|last=Augenstein|first=Seth|date=2019-05-23|website=Forensic Magazine|language=en|access-date=2019-05-24}}</ref> and Family Tree DNA shut down their Y-DNA database ysearch.org, making it more difficult for law enforcement agencies to solve cases.<ref>{{Cite web|url=https://www.forensicmag.com/news/2018/05/golden-state-killer-backlash-public-databases-shutting-down-wake-arrest|title=Golden State Killer Backlash? Public Databases Shutting Down in Wake of Arrest|last=Augenstein|first=Seth|date=2018-05-24|website=Forensic Magazine|language=en|access-date=2019-05-24}}</ref>
Hart, Anne - [http://www.newswriting.net/id102.htm How to Interpret Family History & Ancestry DNA Test Results for Beginners], includes books, online articles and videos on genetic genealogy by this journalist and author


==Drawbacks==
Howells, Cyndi (n.d.). ''Netting Your Ancestors – Genealogical Research on the Internet.'' Baltimore: Genealogical Publishing Company. Guide to electronic sources by author of Cyndi’s List website.
Common concerns about genealogical DNA testing are cost and [[genetic privacy|privacy issues]].<ref>{{cite news|url=https://www.usatoday.com/story/news/nation/2013/06/13/dna-detectives-seek-origins-of-you/2420071/|title=DNA detectives seek origins of you|last=Vergano|first=Dan|date=2013-06-13|newspaper=USA Today|access-date=2016-07-05}}</ref> Some testing companies, such as [[23andMe]] and [[Ancestry.com|Ancestry]],<ref>{{cite web|url=https://dna-explained.com/2015/12/30/23andme-ancestry-and-selling-your-dna-information/|title=23andMe, Ancestry and Selling Your DNA Information|last=Estes|first=Roberta|date=2015-12-30|website=DNAeXplained – Genetic Genealogy|access-date=2016-07-05}}</ref> retain samples and results for their own use without a privacy agreement with subjects.<ref>{{cite magazine|url=http://www.scientificamerican.com/article/23andme-is-terrifying-but-not-for-the-reasons-the-fda-thinks/|title=23andMe Is Terrifying, but Not for the Reasons the FDA Thinks; The genetic-testing company's real goal is to hoard your personal data|last=Seife|first=Charles|date=2013-11-27|magazine=Scientific American|access-date=2016-07-05}}</ref><ref>{{cite journal | vauthors = Wallace SE, Gourna EG, Nikolova V, Sheehan NA | title = Family tree and ancestry inference: is there a need for a 'generational' consent? | journal = BMC Medical Ethics | volume = 16 | issue = 1 | page = 87 | date = December 2015 | pmid = 26645273 | pmc = 4673846 | doi = 10.1186/s12910-015-0080-2 | doi-access = free }}</ref>


Autosomal DNA tests can identify relationships but they can be misinterpreted.<ref>{{cite news|url=https://www.telegraph.co.uk/news/science/science-news/9912822/DNA-ancestry-tests-branded-meaningless.html|title=DNA ancestry tests branded 'meaningless'|last=Collins|first=Nick|date=2013-03-17|newspaper=The Telegraph|access-date=2016-07-05}}</ref><ref>{{Cite news|url=https://www.theguardian.com/science/blog/2013/feb/25/viking-ancestors-astrology|title=To claim someone has 'Viking ancestors' is no better than astrology|last=Thomas|first=Mark|date=2013-02-25|newspaper=The Guardian|access-date=2016-07-05}}</ref><ref>{{cite web|url=https://ghr.nlm.nih.gov/primer/testing/ancestrytesting|title=What is genetic ancestry testing?|last=Reference|date=2016-11-22|website=Genetics Home Reference|publisher=U.S National Library of Medicine|access-date=2016-11-24}}</ref> For example, transplants of stem cell or bone marrow will produce matches with the donor. In addition, identical twins (who have identical DNA) can give unexpected results.<ref>{{cite web|url=https://www.legalgenealogist.com/2017/10/01/dna-doesnt-lie/|title=DNA doesn't lie!|date=1 October 2017}}</ref>
Jobling, M. (2003). ''Human Evolutionary Genetics.'' Standard college and graduate school level textbook by leading expert.


Testing of the Y-DNA lineage from father to son may reveal complications, due to unusual mutations, secret adoptions, and [[non-paternity event]]s (i.e., that the perceived father in a generation is not the father indicated by written birth records).<ref>{{cite web|url=https://isogg.org/wiki/Non-paternity_event|title=Non-paternity event – ISOGG Wiki|website=isogg.org}}</ref> According to the Ancestry and Ancestry Testing Task Force of the [[American Society of Human Genetics]], autosomal tests cannot detect "large portions" of DNA from distant ancestors because it has not been inherited.<ref>{{cite magazine|url=http://blogs.scientificamerican.com/observations/genetic-ancestry-testing-is-an-inexact-science-task-force-says/|title=Genetic ancestry testing is an inexact science, task force says|last=Harmon|first=Katherine|date=2010-05-14|magazine=Scientific American|access-date=2016-07-05}}</ref>
Kerchner, Charles F. Jr. (2004). Self-published. ''[http://www.ggdictionary.com Genetic Genealogy DNA Testing Dictionary].'' Lookup source for esoteric terminology used.


With the increasing popularity of the use of DNA tests for ethnicity tests, uncertainties and errors in ethnicity estimates are a drawback for Genetic genealogy. While ethnicity estimates at the continental level should be accurate (with the possible exception of East Asia and the Americas), sub-continental estimates, especially in Europe, are often inaccurate. Customers may be misinformed about the uncertainties and errors of the estimates.<ref>{{Cite web|url=https://dna-explained.com/2017/01/11/concepts-calculating-ethnicity-percentages/|title=Concepts – Calculating Ethnicity Percentages|first=Roberta|last=Estes|date=11 January 2017|website=DNAeXplained - Genetic Genealogy}}</ref>
Olson, Steve (2002). ''Mapping Human History.'' Boston: Houghton Mifflin Company. Survey of major populations.


Some have recommended government or other regulation of ancestry testing to ensure its performance to an agreed standard.<ref>{{cite journal | vauthors = Lee SS, Soo-Jin Lee S, Bolnick DA, Duster T, Ossorio P, Tallbear K | title = Genetics. The illusive gold standard in genetic ancestry testing | journal = Science | volume = 325 | issue = 5936 | pages = 38–39 | date = July 2009 | pmid = 19574373 | doi = 10.1126/science.1173038 | s2cid = 206519537 }}</ref>
Oppenheimer, Stephen (2003). ''The Real Eve. Modern Man’s Journey out of Africa.'' Carroll & Graf. Champions the “beachcomber route” theory with much technical detail.


A number of law enforcement agencies took legal action to compel
PBS (2003). ''The Journey of Man'' DVD. Broadcast aired in January of 2003, Spencer Wells, host.
genetic genealogy companies to release genetic information that could match [[cold case]] crime victims<ref>{{Cite journal|url=https://www.theatlantic.com/science/archive/2017/08/jane-doe-murder-ancestry/536916/|title=Solving a Murder Mystery With Ancestry Websites|journal=The Atlantic|first=Ciara|last=O'Rourke|date=2017-08-16}}</ref> or perpetrators. A number of companies fought the requests.<ref>{{Cite news|url=https://www.scientificamerican.com/article/the-golden-state-killer-case-was-cracked-with-a-genealogy-web-site1/|title=The Golden State Killer Case Was Cracked with a Genealogy Web Site|last=Robbins|first=Rebecca|date=2018-04-28|work=Scientific American / STAT|access-date=2018-04-30}}</ref>


===Common misunderstandings of genetics===
Panther-Yates, Donald and Elizabeth Caldwell Hirschman (2006). “DNA Haplotyping and Diversity: An Anthropogenealogical Method for Researching Lineages and Family Ethnicity,” ''[[International Journal of the Humanities]]'' 2:2043-55. Guide to finding matches in world databanks and interpreting genetic information in terms of history and recent emigration studies.
{{Main|Common misunderstandings of genetics}}


The popular consciousness of DNA testing and of DNA generally is subject to a number of misconceptions involving the reliability of testing, the nature of the connections with one's ancestors, the connection between DNA and personal traits, etc.<ref>{{cite journal |last1=Zimmer |first1=Carl |author-link1=Carl Zimmer |title=Seven Big Misconceptions about Heredity |journal=[[Skeptical Inquirer]] |date=2019 |volume=43 |issue=3 |pages=34–39 |url=https://skepticalinquirer.org/2019/05/seven-big-misconceptions-about-heredity |archive-url=https://web.archive.org/web/20190808143623/https://skepticalinquirer.org/2019/05/seven-big-misconceptions-about-heredity |url-status=dead |archive-date=2019-08-08 |access-date=8 August 2019}}</ref>
Pomery, Chris (2004) ''DNA and Family History: How Genetic Testing Can Advance Your Genealogical Research.'' London: National Archives. Early guide for do-it-yourself genealogists.


==Medical information==
Savin, Alan (2003). ''DNA for Family Historians.'' Maidenhead: Genetic Genealogy Guides. Slim paperback first published in 2000, now available also in German.
Though genealogical DNA tests are not designed mainly for medical purposes, autosomal DNA tests can be used to analyze the probability of hundreds of heritable medical conditions,<ref>{{Cite web|url=https://www.snpedia.com/index.php/Category:Is_a_medical_condition|title=List of medical conditions – SNPedia|website=www.snpedia.com|access-date=2019-06-27}}</ref> albeit the result is complex to understand and may confuse a non-expert. 23andMe provides medical and trait information from their genealogical DNA test<ref>{{Cite news|url=http://thednageek.com/the-pros-and-cons-of-the-main-autosomal-dna-testing-companies/|title=The Pros and Cons of the Main Autosomal DNA Testing Companies|date=2016-11-14|work=The DNA Geek|access-date=2018-05-19}}</ref> and for a fee the [[Promethease]] web site analyses genealogical DNA test data from Family Tree DNA, 23andMe, or AncestryDNA for medical information.<ref>{{Cite news|url=https://thegeneticgenealogist.com/2013/09/22/what-else-can-i-do-with-my-dna-test-results/|title=What Else Can I Do with My DNA Test Results?|last=Bettinger|first=Blaine|date=2013-09-22|work=The Genetic Genealogist|access-date=2018-05-19}}</ref> Promethease, and its research paper crawling database SNPedia, has received criticism for technical complexity and a poorly defined "magnitude" scale that causes misconceptions, confusion and panic among its users.<ref>{{Cite journal|url=https://slate.com/technology/2016/01/some-personal-genetic-analysis-is-error-prone-and-dishonest.html|title = What's in Your Genes? Some Companies Analyzing Your DNA Use Junk Science| journal=Slate |date = 20 January 2016 | last1=Arthur | first1=Rob }}</ref>


The testing of full MtDNA and YDNA sequences is still somewhat controversial as it may reveal even more medical information. For example, a correlation exists between a lack of [[List of Y-STR markers#DYS464|Y-DNA marker DYS464]] and [[infertility]], and between [[Haplogroup H (mtDNA)|mtDNA haplogroup H]] and protection from [[sepsis]]. Certain haplogroups have been linked to longevity in some population groups.<ref>{{cite journal | vauthors = De Benedictis G, Rose G, Carrieri G, De Luca M, Falcone E, Passarino G, Bonafe M, Monti D, Baggio G, Bertolini S, Mari D, Mattace R, Franceschi C | title = Mitochondrial DNA inherited variants are associated with successful aging and longevity in humans| journal = FASEB Journal | volume = 13 | issue = 12 | pages = 1532–36 | date = September 1999 | pmid = 10463944 | doi=10.1096/fasebj.13.12.1532| doi-access = free| s2cid = 8699708}}</ref><ref>{{cite journal|url=https://www.nature.com/articles/5200703.pdf?origin=ppub|title=European Journal of Human Genetics (2001) 9, pp 701±707|journal=European Journal of Human Genetics |date=September 2001 |volume=9 |issue=9 |pages=701–707 |doi=10.1038/sj.ejhg.5200703 |last1=Rose |first1=Giuseppina |last2=Passarino |first2=Giuseppe |last3=Carrieri |first3=Giuseppina |last4=Altomare |first4=Katia |last5=Greco |first5=Valentina |last6=Bertolini |first6=Stefano |last7=Bonafè |first7=Massimiliano |last8=Franceschi |first8=Claudio |last9=De Benedictis |first9=Giovanna |pmid=11571560 |s2cid=13730557 }}</ref> The field of linkage disequilibrium, unequal association of genetic disorders with a certain mitochondrial lineage, is in its infancy, but those mitochondrial mutations that have been linked are searchable in the genome database Mitomap.<ref>{{cite web|url=http://www.mitomap.org |title=Mitomap |publisher=Mitomap |access-date=2011-06-15}}</ref> Family Tree DNA's MtFull Sequence test analyses the full MtDNA genome<ref name=":3"/> and the National Human Genome Research Institute operates the Genetic And Rare Disease Information Center<ref>{{cite web|url=http://www.genome.gov/10000409 |title=Genetic And Rare Disease Information Center (GARD) |work=Genome.gov |date=22 March 2011 |access-date=2011-06-15}}</ref> that can assist consumers in identifying an appropriate [[Genetic testing|screening test]] and help locate a nearby medical center that offers such a test.
Shawker, Thomas H. (2004). Unlocking Your Genetic History: A Step-by-Step Guide to Discovering Your Family's Medical and Genetic Heritage (National Geneological Society Guide, 6). Guide to the difficult subject of family medical history and genetic diseases.


==DNA testing for consumers==
[[Smolenyak, Megan|Megan Smolenyak]] and Ann Turner (2005). ''Trace Your Roots with DNA: Using Genetic Tests to Explore Your Family Tree.'' Rodale Books. Recent tool for amateur genealogists by seminar speaker and DNA listserv moderator.
The first company to provide [[direct-to-consumer]] genealogical DNA tests was the now defunct [[GeneTree]]. However, it did not offer multi-generational genealogy tests. In fall 2001, GeneTree sold its assets to Salt Lake City-based [[Sorenson Molecular Genealogy Foundation]] (SMGF) which originated in 1999.<ref name=Wayne2006>{{cite journal|url=http://www.med.wayne.edu/news_media/scribe/PDF/Alum-06-SpringScribe%5B1%5D.pdf|title=CMMG alum launches multi-million dollar genetic testing company |journal=Alum Notes|publisher=Wayne State University School of Medicine |volume=17|date=Spring 2006|page=1|access-date=24 January 2013|issue=2|archive-url=https://web.archive.org/web/20170809053626/http://www2.med.wayne.edu/news_media/scribe/PDF/Alum-06-SpringScribe%5b1%5d.pdf|archive-date=9 August 2017|url-status=dead}}</ref>
While in operation, SMGF provided free Y-chromosome and mitochondrial DNA tests to thousands.<ref name=Blaine2006>{{cite web|url=http://www.thegeneticgenealogist.com/2007/11/06/how-big-is-the-genetic-genealogy-market/|title=How Big Is the Genetic Genealogy Market?|publisher=The Genetic Genealogist|access-date=19 February 2009|date=2007-11-06}}</ref>
Later, GeneTree returned to genetic testing for genealogy in conjunction with the Sorenson parent company and eventually was part of the assets acquired in the [[Ancestry.com]] buyout of SMGF in 2012.<ref>{{Cite web|url=https://www.familytreemagazine.com/articles/genealogy-websites/ancestry/ancestry-com-acquisition-means-changes-at-genetree-and-smgf-org/|title=Ancestry.com Acquisition Means Changes at GeneTree and SMGF.org|last=Dobush|first=Grace|date=2012-07-12|website=Family Tree|access-date=2019-04-10|archive-date=10 April 2019|archive-url=https://web.archive.org/web/20190410095000/https://www.familytreemagazine.com/articles/genealogy-websites/ancestry/ancestry-com-acquisition-means-changes-at-genetree-and-smgf-org/|url-status=dead}}</ref><ref name=SMGF2012>{{cite press release|url=http://corporate.ancestry.com/press/press-releases/2012/05/ancestry.com-dna-launches/|access-date=1 July 2013|title=Ancestry.com Launches new AncestryDNA Service: The Next Generation of DNA Science Poised to Enrich Family History Research|url-status=dead|archive-url=https://web.archive.org/web/20130526104607/http://corporate.ancestry.com/press/press-releases/2012/05/ancestry.com-dna-launches/|archive-date=26 May 2013}}</ref>


In 2000, [[Family Tree DNA]], founded by [[Bennett Greenspan]] and Max Blankfeld, was the first company dedicated to direct-to-consumer testing for genealogy research. They initially offered eleven-marker Y-Chromosome STR tests and HVR1 mitochondrial DNA tests. They originally tested in partnership with the University of Arizona.<ref name=Belli>{{cite news|last=Belli|first=Anne|title=Moneymakers: Bennett Greenspan|url=http://www.chron.com/business/article/Moneymakers-Bennett-Greenspan-1657195.php|access-date=14 June 2013|newspaper=Houston Chronicle|date=18 January 2005|quote=Years of researching his family tree through records and documents revealed roots in Argentina, but he ran out of leads looking for his maternal great-grandfather. After hearing about new genetic testing at the University of Arizona, he persuaded a scientist there to test DNA samples from a known cousin in California and a suspected distant cousin in Buenos Aires. It was a match. But the real find was the idea for Family Tree DNA, which the former film salesman launched in early 2000 to provide the same kind of service for others searching for their ancestors.}}</ref><ref name=NGSQ2005>{{cite journal |author1=Ugo A. Perego |author2=Ann Turner |author3=Jayne E. Ekins |author4=Scott R. Woodward |title=The Science of Molecular Genealogy |journal=National Genealogical Society Quarterly|volume=93|issue=1–4|publisher=National Genealogical Society|date=December 2005|page=248|quote=Businessman Bennett Greenspan hoped that the approach used in the Jefferson and Cohen research would help family historians. After reaching a brick wall on his mother's surname, Nitz, he discovered and Argentine researching the same surname. Greenspan enlisted the help of a male Nitz cousin. A scientist involved in the original Cohen investigation tested the Argentine's and Greenspan's cousin's Y chromosomes. Their haplotypes matched perfectly.}}</ref>
[[Bryan Sykes|Sykes, Bryan]] (2001) ''[[The Seven Daughters of Eve|The Seven Daughters of Eve. The Science that Reveals Our Genetic Ancestry]].'' New York, Norton. Names the founders of Europe’s major female haplogroups [[Haplogroup H (mtDNA)|Helena]], [[Haplogroup J (mtDNA)|Jasmine]], [[Haplogroup K (mtDNA)|Katrine]], [[Haplogroup T (mtDNA)|Tara]], [[Haplogroup V (mtDNA)|Velda]], [[Haplogroup X (mtDNA)|Xenia]], and [[Haplogroup U (mtDNA)|Ursula]].
<ref name=Lomax>{{cite news|last=Lomax|first=John Nova|title=Who's Your Daddy?|url=http://www.houstonpress.com/2005-04-14/news/who-s-your-daddy/|access-date=14 June 2013|newspaper=Houston Press|date=14 April 2005|quote=A real estate developer and entrepreneur, Greenspan has been interested in genealogy since his preteen days.}}</ref><ref name=Dardashti>{{cite news|last=Dardashti|first=Schelly Talalay|title=When oral history meets genetics| url=http://www.jpost.com/Features/In-Thespotlight/When-oral-history-meets-genetics|access-date=14 June 2013|newspaper=The Jerusalem Post|date=30 March 2008|quote=Greenspan, born and raised in Omaha, Nebraska, has been interested in genealogy from a very young age; he drew his first family tree at age 11.}}</ref>
<ref name=HBJ2008>{{cite news|last=Bradford|first=Nicole|title=Riding the 'genetic revolution'|newspaper=Houston Business Journal|date=24 February 2008|url=http://www.bizjournals.com/houston/stories/2008/02/25/smallb1.html?page=all|access-date=19 June 2013}}</ref>


In 2007, [[23andMe]] was the first company to offer a [[saliva]]-based [[Genetic testing#Direct-to-consumer genetic testing|direct-to-consumer genetic testing]].<ref name = Time>{{Cite magazine|last=Hamilton|first=Anita|url=http://www.time.com/time/specials/packages/article/0,28804,1852747_1854493,00.html |archive-url=https://web.archive.org/web/20081102044918/http://www.time.com/time/specials/packages/article/0,28804,1852747_1854493,00.html |url-status=dead |archive-date=2 November 2008 | title = Best Inventions of 2008 | magazine = [[Time (magazine)|Time]] | date=29 October 2008 | access-date = 5 April 2012}}</ref> It was also the first to implement the use of autosomal DNA for ancestry testing, which other major companies (e.g., Ancestry, Family Tree DNA, and [[MyHeritage]]) now use.<ref>{{cite web |url=https://mediacenter.23andme.com/company/about-us |title=About Us |website=23andMe |access-date=11 February 2018 |archive-date=26 February 2018 |archive-url=https://web.archive.org/web/20180226180950/https://mediacenter.23andme.com/company/about-us/ |url-status=dead }}</ref><ref>{{Cite book |chapter-url=https://isogg.org/wiki/Autosomal_DNA_testing_comparison_chart |title=Autosomal DNA testing comparison chart |website=International Society of Genetic Genealogy Wiki |last1=Janzen |first1=Tim |display-authors=etal |chapter=Family Tree DNA Learning Center |publisher=Gene by Gene }}</ref>
[[Bryan Sykes|Sykes, Bryan]] (2004). ''[[Adam's Curse|Adam's Curse. A Future without Men]].'' New York: W. W. Norton. The Oxford professor’s male sequel to The Seven Daughters of Eve.


[[MyHeritage]] launched its genetic testing service in 2016, allowing users to use [[cheek swab]]s to collect samples.<ref name="TCrucnhDAN">{{cite news|last1=Lardinois|first1=Frederic|title=MyHeritage launches DNA testing service to help you uncover your family's history|url=https://techcrunch.com/2016/11/07/myheritage-launches-dna-testing-service-to-help-you-uncover-your-familys-history/|access-date=13 December 2016|work=TechCrunch|date=7 November 2016}}</ref> In 2019, new analysis tools were presented: autoclusters (grouping all matches visually into clusters)<ref>{{Cite web|url=https://blog.myheritage.com/2019/02/introducing-autoclusters-for-dna-matches/|title=Introducing AutoClusters for DNA Matches|date=2019-02-28|website=MyHeritage Blog}}</ref> and family tree theories (suggesting conceivable relations between DNA matches by combining several Myheritage trees as well as the Geni global family tree).<ref>{{Cite web|url=https://www.danaleeds.com/myheritages-theory-of-family-relativity-an-exciting-new-tool/|title=MyHeritage's "Theory of Family Relativity": An Exciting New Tool!|date=2019-03-15|website=DanaLeeds.com|language=en-US}}</ref>
Tagliaferro, Linda (1999). ''The Complete Idiot’s Guide to Decoding Your Genes.'' Alpha Books. Uses everyday language to explain the role genes play in shaping who we are. Light on genealogy and a bit outdated.


[[Living DNA]], founded in 2015, also provides a genetic testing service. Living DNA uses [[SNP chip]]s to provide reports on autosomal ancestry, Y, and mtDNA ancestry.<ref>{{Cite web|url=https://www.techradar.com/reviews/living-dna-review|title=Living DNA review|date=21 June 2019}}</ref><ref>{{Cite web|url=https://www.cnn.com/2019/04/22/cnn-underscored/living-dna-review-dna-testing-for-ethnicity/index.html|title = Is this the most detailed at-home DNA testing kit yet?|website = [[CNN]]|date = 22 April 2019}}</ref> Living DNA provides detailed reports on ancestry from the UK as well as detailed Y chromosome and mtDNA reports.<ref>{{Cite book | url=https://books.google.com/books?id=Qro1DwAAQBAJ&q=%22living+dna%22&pg=PT299 | title=Scottish Genealogy| isbn=9780752488479| last1=Durie| first1=Bruce| date=January 2012| publisher=The History Press| edition=Fourth}}</ref><ref>{{cite web |url=https://www.familytreemagazine.com/premium/dna-test-series-part-6 |title=Comparing the 5 Major DNA Tests: Living DNA - Family Tree |website=www.familytreemagazine.com |url-status=dead |archive-url=https://web.archive.org/web/20180802234034/https://www.familytreemagazine.com/premium/dna-test-series-part-6 |archive-date=2018-08-02}} </ref><ref>{{Cite web|url=https://www.sciencenews.org/article/family-dna-ancestry-tests-review-comparison|title = What I actually learned about my family after trying 5 DNA ancestry tests|date = 13 June 2018}}</ref>
Wells, Spencer (2004). ''The Journey of Man.'' New York: Random House.

</div>
In 2019 it was estimated that large genealogical testing companies had about 26 million DNA profiles.<ref>{{Cite web|url=https://www.technologyreview.com/s/612880/more-than-26-million-people-have-taken-an-at-home-ancestry-test/|title=More than 26 million people have taken an at-home ancestry test|last=Regalado|first=Antonio|date=2019-02-11|website=MIT Technology Review|access-date=2019-04-10}}</ref><ref name=":4">{{Cite news|url=https://www.haaretz.com/us-news/.premium.MAGAZINE-to-solve-cold-cases-all-it-takes-is-dna-a-genealogy-site-and-high-speed-internet-1.6657176|title=To Solve Cold Cases, All It Takes Is Crime Scene DNA, a Genealogy Site and High-speed Internet|last=Michaeli|first=Yarden|date=2018-11-16|work=Haaretz|access-date=2018-11-21}}</ref> Many transferred their test result for free to multiple testing sites, and also to genealogical services such as [[Geni.com]] and [[GEDmatch]]. GEDmatch said in 2018 that about half of their one million profiles were from the USA.<ref name=":4"/>

==DNA in genealogy software==
Some [[Comparison of genealogy software|genealogy software]] programs – such as Family Tree Maker, Legacy Family Tree (Deluxe Edition) and the Swedish program Genney – allow recording DNA marker test results. This allows for tracking of both Y-chromosome and mtDNA tests, and recording results for relatives.<ref>{{cite web|url=http://thegeneticgenealogist.com/2013/09/22/what-else-can-i-do-with-my-dna-test-results/|title=What Else Can I Do with My DNA Test Results?|last=Bettinger|first=Blaine|date=2013-09-22|website=The Genetic Genealogist|access-date=2016-11-24}}</ref>


==See also==
==See also==
{{Main|List of genetic genealogy topics}}
*[[Autosome]]
{{Div col|colwidth=30em}}
*[[Electropherogram]]
* [[Archaeogenetics]]
*[[Genetic fingerprinting]]
* [[Common misunderstandings of genetics]]
*[[Genetic genealogy]]
*[[Genetic testing]]
* [[DNA paternity testing]]
*[[Haplogroup]]
* [[Electropherogram]]
* [[Family name]] (patrilineal surname)
*[[Haplotype]]
* [[Genetic fingerprinting]]
*[[International HapMap Project]]
* [[Genetic Information Nondiscrimination Act]]
*[[List of DNA tested mummies]]
* [[Genographic Project]] ([[Geno 2.0 Next Generation]])
*[[List of DYS markers]]
* [[International HapMap Project]]
*[[Mitochondrial DNA]]
* [[International Society of Genetic Genealogy]]
*[[Paternity test]]
*[[Short tandem repeat]]
* [[List of DNA tested mummies]]
* [[:Category: Genetic genealogy companies]], including:
*[[Single nucleotide polymorphism]]
** [[23andMe]]
** [[Ancestry.com]]
** [[Family Tree DNA]]
** [[Living DNA]]
** [[MyHeritage]]
{{div col end}}

==References==
{{Reflist}}

=== Sources ===


* {{cite book |last1=Bettinger |first1=Blaine T. |title=Genetic Genealogy in Practice |last2=Wayne |first2=Debbie Parker |date=2016 |publisher=National Genealogical Society |isbn=978-1-935815-22-8 |location=Arlington, VA |name-list-style=vanc}}
==External links==


==Further reading==
===Testing comparisons===
{{Refbegin}}
*''duerinck.com:'' [http://www.duerinck.com/dnalabs.html Genetic Genealogy Laboratory Testing Sites] rev. July 2006
* {{cite book | first1 = Megan | last1 = Smolenyak | first2 = Ann | last2 = Turner | name-list-style = vanc |title=Trace your roots with DNA: using genetic tests to explore your family tree|url=https://books.google.com/books?id=J9evrYLpDVEC&pg=PP1|date=12 October 2004|publisher=Rodale|isbn=978-1-59486-006-5}}
*''ISOGG:'' [http://www.isogg.org/mtdnachart.htm mtDNA Testing Company Comparison Chart]
* {{cite book | first1 = Chris | last1 = Pomery | first2 = Steve | last2 = Jones | name-list-style = vanc |title=DNA and family history: how genetic testing can advance your genealogical research|url=https://books.google.com/books?id=Kzv0vp6KdbgC&pg=PP1|date=1 October 2004|publisher=Dundurn Press Ltd.|isbn=978-1-55002-536-1}}
*''ISOGG:'' [http://www.isogg.org/ydnachart.htm Y-DNA Testing Company Comparison Chart]
{{Refend}}
*''mymcgee.com:'' [http://www.mymcgee.com/results.html#ymarkers Y-DNA Test Pricing & Alleles Comparison Charts]
* [http://www.roperld.com/YBiallelicHaplogroups.htm#pref Y-Haplogroups brief descriptions and regional origins]
* [https://www.geneticsandsociety.org/biopolitical-times/ancestrydna-markets-genetic-greatness-during-olympics AncestryDNA Markets Genetic "Greatness" During the Olympics, by Leah Lowthorp | 03.16.2018, Biopolitical Times.]


{{Genealogical DNA test}}
===Haplogroup prediction===
{{Human genetics}}
*''Athey Surname Project:'' [https://home.comcast.net/~whitathey/predictorinstr.htm Y-Haplogroup Predictor]
{{Y-chromosome haplogroups by population}}
*''Arizona University:'' [http://ycc.biosci.arizona.edu/nomenclature_system/fig1.html Y-DNA Haplogroup Tree]
{{Authority control}}
*''dnaconsultants.com:'' [http://dnaconsultants.com/images/links/49-conversion.pdf Conversion Chart for Male Haplogroups] (PDF)
*''dnaheritage.com:'' [http://www.dnaheritage.com/masterclass2.asp Masterclass tutorial on SNP's and haplogroups]


[[Category:Population genetics|Genealogical DNA tests]]
{{DEFAULTSORT:Genealogical Dna Test}}
[[Category:DNA]]
[[Category:Genetic genealogy]]
[[Category:Genetic genealogy]]
[[Category:Genealogy|DNA tests]]
[[Category:Genetics techniques]]
[[Category:DNA|Genealogical DNA tests]]
[[Category:Human population genetics]]
[[Category:Kinship and descent|Genealogical DNA tests]]

Latest revision as of 14:52, 18 November 2024

A genealogical DNA test is a DNA-based genetic 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 mixture of an individual. Since different testing companies use different ethnic reference groups and different matching algorithms, ethnicity estimates for an individual 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 being useful for different types of genealogical research: autosomal (atDNA), mitochondrial (mtDNA), and Y-chromosome (Y-DNA).

Autosomal tests may result in a large number of DNA matches to both males and females who have also tested with the same company. Each match will typically show an estimated degree of relatedness, i.e., a close family match, 1st-2nd cousins, 3rd-4th cousins, etc. The furthest degree of relationship is usually the "6th-cousin or further" level. However, due to the random nature of which, and how much, DNA is inherited by each tested person from their common ancestors, precise relationship 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. However, they give considerably fewer DNA matches, if any (depending on the company doing the testing), since they are limited to relationships along a strict female line and a strict male line respectively. MtDNA and Y-DNA tests are utilized to identify archeological cultures and migration paths of a person's ancestors along a strict mother's line or a strict father's line. Based on MtDNA and Y-DNA, a person's haplogroup(s) can be identified. The mtDNA test can be taken by both males and females, because everyone inherits their mtDNA from their mother, as the mitochondrial DNA is located in the egg cell. However, a Y-DNA test can only be taken by a male, as only males have a Y-chromosome.

Procedure

[edit]
How to obtain genotypes from spit. The video shows the process of extracting genotypes from a human spit sample using a DNA microarray, which is the most common method used in genetic genealogy.

A genealogical DNA test is performed on a DNA sample obtained by cheek-scraping (also known as a buccal swab), spit-cups, mouthwash, or chewing gum. Typically, the sample collection uses a home test kit supplied by a service provider such as 23andMe, AncestryDNA, Family Tree DNA, or MyHeritage. After following the kit instructions on how to collect the sample, it is returned to the supplier for analysis. The sample is then processed using a technology known as DNA microarray to obtain the genetic information.

Types of tests

[edit]

There are three major types of genealogical DNA tests: Autosomal (which includes X-DNA), Y-DNA, and mtDNA.

  • Autosomal DNA tests look at chromosome pairs 1–22 and the X part of the 23rd chromosome. The autosomes (chromosome pairs 1–22) are inherited from both parents and all recent ancestors. The X-chromosome follows a special inheritance pattern, because females (XX) inherit an X-chromosome from each of their parents, while males (XY) inherit an X-chromosome from their mother and a Y-chromosome from their father (XY). Ethnicity estimates are often included with this sort of testing.
  • Y-DNA looks at the Y-chromosome, which is passed down from father to son. Thus, the Y-DNA test can only be taken by males to explore their direct paternal line.
  • mtDNA looks at the mitochondria, which is passed down from mother to child. Thus, the mtDNA test can be taken by both males and females, and it explores one's direct maternal line.[1]

Y-DNA and mtDNA cannot be used for ethnicity estimates, but can be used to find one's haplogroup, which is unevenly distributed geographically.[2] Direct-to-consumer DNA test companies have often labeled haplogroups by continent or ethnicity (e.g., an "African haplogroup" or a "Viking haplogroup"), but these labels may be speculative or misleading.[2][3][4]

Autosomal DNA (atDNA) testing

[edit]

Testing

[edit]

Autosomal DNA is contained in the 22 pairs of chromosomes not involved in determining a person's sex.[2] Autosomal DNA recombines in each generation, and new offspring receive one set of chromosomes from each parent.[5] These are inherited exactly equally from both parents and roughly equally from grandparents to about 3x great-grandparents.[6] Therefore, the number of markers (one of two or more known variants in the genome at a particular location – known as Single-nucleotide polymorphisms or SNPs) inherited from a specific ancestor decreases by about half with each successive generation; that is, an individual receives half of their markers from each parent, about a quarter of those markers from each grandparent; about an eighth of those markers from each great-grandparent, etc. Inheritance is more random and unequal from more distant ancestors.[7] Generally, a genealogical DNA test might test about 700,000 SNPs (specific points in the genome).[8]

Shared DNA for different relatives

Reporting process

[edit]

The preparation of a report on the DNA in the sample proceeds in multiple stages:

  • identification of the DNA base pair at specific SNP locations
  • comparison with previously stored results
  • interpretation of matches
Base pair identification
[edit]

All major service providers use equipment with chips supplied by Illumina.[9] The chip determines which SNP locations are tested. Different versions of the chip are used by different service providers. In addition, updated versions of the Illumina chip may test different sets of SNP locations. The list of SNP locations and base pairs at that location is usually available to the customer as "raw data". The raw data can be uploaded to some other genealogical service providers to produce an additional interpretation and matches. For additional genealogical analysis the data can also be uploaded to GEDmatch (a third-party web based set of tools that analyzes raw data from the main service providers). Raw data can also be uploaded to services that provide health risk and trait reports using SNP genotypes. These reports may be free or inexpensive, in contrast to reports provided by DTC testing companies, who charge about double the cost of their genealogy-only services. The implications of individual SNP results can be ascertained from raw data results by referring to SNPedia.com.

Identification of Matches

[edit]

The major component of an autosomal DNA test is matching other individuals. Where the individual being tested has a number of consecutive SNPs in common with a previously tested individual in the company's database, it can be inferred that they share a segment of DNA at that part of their genomes.[10] If the segment is longer than a threshold amount set by the testing company, then these two individuals are considered to be a match. Unlike the identification of base pairs, the data bases against which the new sample is tested, and the algorithms used to determine a match, are proprietary and specific to each company.

The unit for segments of DNA is the centimorgan (cM). For comparison, a full human genome is about 6500 cM. The shorter the length of a match, the greater are the chances that a match is spurious.[11] An important statistic for subsequent interpretation is the length of the shared DNA (or the percentage of the genome that is shared).

Interpretation of Autosomal matches

[edit]

Most companies will show the customers how many cMs they share and across how many segments. From the number of cMs and segments, the relationship between the two individuals can be estimated; however, due to the random nature of DNA inheritance, relationship estimates, especially for distant relatives, are only approximate. Some more distant cousins will not match at all.[12] Although information about specific SNPs can be used for some purposes (e.g., suggesting likely eye color), the key information is the percentage of DNA shared by two individuals. This can indicate the closeness of the relationship. However, it does not show the roles of the two individuals, e.g., 50% shared suggests a parent/child relationship, but it does not identify which individual is the parent.

Various advanced techniques and analyses can be done on this data. This includes features such as In-common/Shared Matches,[13] Chromosome Browsers,[14] and Triangulation.[15] This analysis is often required if DNA evidence is being used to prove or disprove a specific relationship.

X-chromosome DNA testing

[edit]

The X-chromosome SNP results are often included in autosomal DNA tests. Both males and females receive an X-chromosome from their mother, but only females receive a second X-chromosome from their father.[16] The X-chromosome has a special path of inheritance patterns and can be useful in significantly narrowing down possible ancestor lines compared to autosomal DNA. For example, an X-chromosome match with a male can only have come from his maternal side.[17] Like autosomal DNA, X-chromosome DNA undergoes random recombination at each generation (except for father-to-daughter X-chromosomes, which are passed down unchanged). There are specialized inheritance charts which describe the possible patterns of X-chromosome DNA inheritance for males and females.[18]

STRs

[edit]

Some genealogical companies offer autosomal STRs (short tandem repeats).[19] These are similar to Y-DNA STRs. The number of STRs offered is limited, and results have been used for personal identification,[20] paternity cases, and inter-population studies.[21][22]

Law enforcement agencies in the US and Europe use autosomal STR data to identify criminals.[19][23]

Mitochondrial DNA (mtDNA) testing

[edit]

The mitochondrion is a component of a human cell, and contains its own DNA. Mitochondrial DNA usually has 16,569 base pairs (the number can vary slightly depending on addition or deletion mutations)[24] and is much smaller than the human genome DNA which has 3.2 billion base pairs. Mitochondrial DNA is transmitted from mother to child, as it is contained in the egg cell. Thus, a direct maternal ancestor can be traced using mtDNA. The transmission occurs with relatively rare mutations compared to autosomal DNA. A perfect match found to another person's mtDNA test results indicates shared ancestry of possibly between 1 and 50 generations ago.[2] More distant matching to a specific haplogroup or subclade may be linked to a common geographic origin.

Test

[edit]

The mtDNA, by current conventions, is divided into three regions. They are the coding region (00577-16023) and two Hyper Variable Regions (HVR1 [16024-16569], and HVR2 [00001-00576]).[25]

The two most common mtDNA tests are a sequence of HVR1 and HVR2 and a full sequence of the mitochondria. Generally, testing only the HVRs has limited genealogical use so it is increasingly popular and accessible to have a full sequence. The full mtDNA sequence is only offered by Family Tree DNA among the major testing companies[26] and is somewhat controversial because the coding region DNA may reveal medical information about the test-taker[27]

Haplogroups

[edit]
Map of human migration out of Africa, according to Mitochondrial DNA. The numbers represent thousands of years before present time. The blue line represents the area covered in ice or tundra during the last great ice age. The North Pole is at the center. Africa, the center of the start of the migration, is at the top left and South America is at the far right.

All humans descend in the direct female line from Mitochondrial Eve, a female who lived probably around 150,000 years ago in Africa.[28][29] Different branches of her descendants are different haplogroups. Most mtDNA results include a prediction or exact assertion of one's mtDNA Haplogroup. Mitochrondial haplogroups were greatly popularized by the book The Seven Daughters of Eve, which explores mitochondrial DNA.

Understanding mtDNA test results

[edit]

It is not normal for test results to give a base-by-base list of results. Instead, results are normally compared to the Cambridge Reference Sequence (CRS), which is the mitochondria of a European who was the first person to have their mtDNA published in 1981 (and revised in 1999).[30] Differences between the CRS and testers are usually very few, thus it is more convenient than listing one's raw results for each base pair.

Examples

Note that in HVR1, instead of reporting the base pair exactly, for example 16,111, the 16 is often removed to give in this example 111. The letters refer to one of the four bases (A, T, G, C) that make up DNA.

Region HVR1 HVR2
Differences from CRS 111T,223T,259T,290T,319A,362C 073G,146C,153G

Y-chromosome (Y-DNA) testing

[edit]

The Y-chromosome is one of the 23rd pair of human chromosomes. Only males have a Y-chromosome, because women have two X chromosomes in their 23rd pair. A man's patrilineal ancestry, or male-line ancestry, can be traced using the DNA on his Y-chromosome (Y-DNA), because the Y-chromosome is transmitted from a father to son nearly unchanged.[31] A man's test results are compared to another man's results to determine the time frame in which the two individuals shared a most recent common ancestor, or MRCA, in their direct patrilineal lines. If their test results are very close, they are related within a genealogically useful time frame.[32] A surname project is where many individuals whose Y-chromosomes match collaborate to find their common ancestry.

Women who wish to determine their direct paternal DNA ancestry can ask their father, brother, paternal uncle, paternal grandfather, or a paternal uncle's son (their cousin) to take a test for them.

There are two types of DNA testing: STRs and SNPs.[2]

STR markers

[edit]

Most common is STRs (short tandem repeat). A certain section of DNA is examined for a pattern that repeats (e.g. ATCG). The number of times it repeats is the value of the marker. Typical tests test between 12 and 111 STR markers. STRs mutate fairly frequently. The results of two individuals are then compared to see if there is a match. DNA companies will usually provide an estimate of how closely related two people are, in terms of generations or years, based on the difference between their results.[33]

SNP markers and Haplogroups

[edit]
Strand 1 differs from strand 2 at a single base pair location (a C → T polymorphism).

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.[34] 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.[35][36] 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).[37]

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.

Using DNA test results

[edit]

Ethnicity estimates

[edit]

Many companies offer a percentage breakdown by ethnicity or region. Generally the world is specified into about 20–25 regions, and the approximate percentage of DNA inherited from each is stated. This is usually done by comparing the frequency of each Autosomal DNA marker tested to many population groups.[2] The reliability of this type of test is dependent on comparative population size, the number of markers tested, the ancestry informative value of the SNPs tested, and the degree of admixture in the person tested. Earlier ethnicity estimates were often wildly inaccurate, but as companies receive more samples over time, ethnicity estimates have become more accurate. Testing companies such as Ancestry.com will often regularly update their ethnicity estimates, which has caused some controversy from customers as their results update.[38][39] Usually the results at the continental level are accurate, but more specific assertions of the test may turn out to be incorrect.[citation needed]

Audience

[edit]

The interest in genealogical DNA tests has been linked to both an increase in curiosity about traditional genealogy and to more general personal origins. Those who test for traditional genealogy often utilize a combination of autosomal, mitochondrial, and Y-Chromosome tests. Those with an interest in personal ethnic origins are more likely to use an autosomal test. However, answering specific questions about the ethnic origins of a particular lineage may be best suited to an mtDNA test or a Y-DNA test.

Maternal origin tests

[edit]

For recent genealogy, exact matching on the mtDNA full sequence is used to confirm a common ancestor on the direct maternal line between two suspected relatives. Because mtDNA mutations are very rare, a nearly perfect match is not usually considered relevant to the most recent 1 to 16 generations.[40] In cultures lacking matrilineal surnames to pass down, neither relative above is likely to have as many generations of ancestors in their matrilineal information table as in the above patrilineal or Y-DNA case: for further information on this difficulty in traditional genealogy, due to lack of matrilineal surnames (or matrinames), see Matriname.[41] However, the foundation of testing is still two suspected descendants of one person. This hypothesize and test DNA pattern is the same one used for autosomal DNA and Y-DNA.

Tests for ethnicity and membership of other groups

[edit]
European genetic structure (based on Autosomal SNPs) by PCA

As discussed above, autosomal tests usually report the ethnic proportions of the individual. These attempt to measure an individual's mixed geographic heritage by identifying particular markers, called ancestry informative markers or AIM, that are associated with populations of specific geographical areas. Geneticist Adam Rutherford has written that these tests "don’t necessarily show your geographical origins in the past. They show with whom you have common ancestry today."[42]

The haplogroups determined by Y-DNA and mtDNA tests are often unevenly geographically distributed. Many direct-to-consumer DNA tests described this association to infer the test-taker's ancestral homeland.[4] Most tests describe haplogroups according to their most frequently associated continent (e.g., a "European haplogroup").[4] When Leslie Emery and collaborators performed a trial of mtDNA haplogroups as a predictor of continental origin on individuals in the Human Genetic Diversity Panel (HGDP) and 1000 Genomes (1KGP) datasets, they found that only 14 of 23 haplogroups had a success rate above 50% among the HGDP samples, as did "about half" of the haplogroups in the 1KGP.[4] The authors concluded that, for most people, "mtDNA-haplogroup membership provides limited information about either continental ancestry or continental region of origin."[4]

African ancestry

[edit]

Y-DNA and mtDNA testing may be able to determine with which peoples in present-day Africa a person shares a direct line of part of his or her ancestry, but patterns of historic migration and historical events cloud the tracing of ancestral groups. Due to joint long histories in the US, approximately 30% of African American males have a European Y-Chromosome haplogroup[43] Approximately 58% of African Americans have at least the equivalent of one great-grandparent (13%) of European ancestry. Only about 5% have the equivalent of one great-grandparent of Native American ancestry. By the early 19th century, substantial families of Free Persons of Color had been established in the Chesapeake Bay area who were descended from free people during the colonial period; most of those have been documented as descended from white men and African women (servant, slave or free). Over time various groups married more within mixed-race, black or white communities.[44]

According to authorities like Salas, nearly three-quarters of the ancestors of African Americans taken in slavery came from regions of West Africa. The African-American movement to discover and identify with ancestral tribes has burgeoned since DNA testing became available. African Americans usually cannot easily trace their ancestry during the years of slavery through surname research, census and property records, and other traditional means. Genealogical DNA testing may provide a tie to regional African heritage.

United States – Melungeon testing

[edit]

Melungeons are one of numerous multiracial groups in the United States with origins wrapped in myth. The historical research of Paul Heinegg has documented that many of the Melungeon groups in the Upper South were descended from mixed-race people who were free in colonial Virginia and the result of unions between the Europeans and Africans. They moved to the frontiers of Virginia, North Carolina, Kentucky and Tennessee to gain some freedom from the racial barriers of the plantation areas.[45] Several efforts, including a number of ongoing studies, have examined the genetic makeup of families historically identified as Melungeon. Most results point primarily to a mixture of European and African, which is supported by historical documentation. Some may have Native American heritage as well. Though some companies provide additional Melungeon research materials with Y-DNA and mtDNA tests, any test will allow comparisons with the results of current and past Melungeon DNA studies.

Native American ancestry

[edit]

The pre-columbian indigenous people of the United States are called "Native Americans" in American English.[46] Autosomal testing, Y-DNA, and mtDNA testing can be conducted to determine the ancestry of Native Americans. A mitochondrial Haplogroup determination test based on mutations in Hypervariable Region 1 and 2 may establish whether a person's direct female line belongs to one of the canonical Native American Haplogroups, A, B, C, D or X. The vast majority of Native American individuals belong to one of the five identified mtDNA Haplogroups. Thus, being in one of those groups provides evidence of potential Native American descent. However, DNA ethnicity results cannot be used as a substitute for legal documentation.[47] Native American tribes have their own requirements for membership, often based on at least one of a person's ancestors having been included on tribal-specific Native American censuses (or final rolls) prepared during treaty-making, relocation to reservations or apportionment of land in the late 19th century and early 20th century. One example is the Dawes Rolls.

Cohanim ancestry

[edit]

The Cohanim (or Kohanim) is a patrilineal priestly line of descent in Judaism. According to the Bible, the ancestor of the Cohanim is Aaron, brother of Moses. Many believe that descent from Aaron is verifiable with a Y-DNA test: the first published study in genealogical Y-Chromosome DNA testing found that a significant percentage of Cohens had distinctively similar DNA, rather more so than general Jewish or Middle Eastern populations. These Cohens tended to belong to Haplogroup J, with Y-STR values clustered unusually closely around a haplotype known as the Cohen Modal Haplotype (CMH). This could be consistent with a shared common ancestor, or with the hereditary priesthood having originally been founded from members of a single closely related clan.

Nevertheless, the original studies tested only six Y-STR markers, which is considered a low-resolution test. In response to the low resolution of the original 6-marker CMH, the testing company FTDNA released a 12-marker CMH signature that was more specific to the large closely related group of Cohens in Haplogroup J1.

A further academic study published in 2009 examined more STR markers and identified a more sharply defined SNP haplogroup, J1e* (now J1c3, also called J-P58*) for the J1 lineage. The research found "that 46.1% of Kohanim carry Y chromosomes belonging to a single paternal lineage (J-P58*) that likely originated in the Near East well before the dispersal of Jewish groups in the Diaspora. Support for a Near Eastern origin of this lineage comes from its high frequency in our sample of Bedouins, Yemenis (67%), and Jordanians (55%) and its precipitous drop in frequency as one moves away from Saudi Arabia and the Near East (Fig. 4). Moreover, there is a striking contrast between the relatively high frequency of J-58* in Jewish populations (»20%) and Kohanim (»46%) and its vanishingly low frequency in our sample of non-Jewish populations that hosted Jewish diaspora communities outside of the Near East."[48]

Recent phylogenetic research for haplogroup J-M267 placed the "Y-chromosomal Aaron" in a subhaplogroup of J-L862, L147.1 (age estimate 5631-6778yBP yBP): YSC235>PF4847/CTS11741>YSC234>ZS241>ZS227>Z18271 (age estimate 2731yBP).[49]

European testing

[edit]

Benefits

[edit]

Genealogical DNA tests have become popular due to the ease of testing at home and their usefulness in supplementing genealogical research. Genealogical DNA tests allow for an individual to determine with high accuracy whether he or she is related to another person within a certain time frame, or with certainty that he or she is not related. DNA tests are perceived as more scientific, conclusive and expeditious than searching the civil records. However, they are limited by restrictions on lines that may be studied. The civil records are always only as accurate as the individuals having provided or written the information.

Y-DNA testing results are normally stated as probabilities: For example, with the same surname a perfect 37/37 marker test match gives a 95% likelihood of the most recent common ancestor (MRCA) being within 8 generations,[50] while a 111 of 111 marker match gives the same 95% likelihood of the MRCA being within only 5 generations back.[51]

As presented above in mtDNA testing, if a perfect match is found, the mtDNA test results can be helpful. In some cases, research according to traditional genealogy methods encounters difficulties due to the lack of regularly recorded matrilineal surname information in many cultures (see Matrilineal surname).[41]

Autosomal DNA combined with genealogical research has been used by adoptees to find their biological parents,[52] has been used to find the name and family of unidentified bodies[53][54] and by law enforcement agencies to apprehend criminals[55][56] (for example, the Contra Costa County District Attorney's office used the "open-source" genetic genealogy site GEDmatch to find relatives of the suspect in the Golden State Killer case.[57][58]). The Atlantic magazine commented in 2018 that "Now, the floodgates are open. ..a small, volunteer-run website, GEDmatch.com, has become ... the de facto DNA and genealogy database for all of law enforcement."[59] Family Tree DNA announced in February 2019 it was allowing the FBI to access its DNA data for cases of murder and rape.[60] However, in May 2019 GEDmatch initiated stricter rules for accessing their autosomal DNA database[61] and Family Tree DNA shut down their Y-DNA database ysearch.org, making it more difficult for law enforcement agencies to solve cases.[62]

Drawbacks

[edit]

Common concerns about genealogical DNA testing are cost and privacy issues.[63] Some testing companies, such as 23andMe and Ancestry,[64] retain samples and results for their own use without a privacy agreement with subjects.[65][66]

Autosomal DNA tests can identify relationships but they can be misinterpreted.[67][68][69] For example, transplants of stem cell or bone marrow will produce matches with the donor. In addition, identical twins (who have identical DNA) can give unexpected results.[70]

Testing of the Y-DNA lineage from father to son may reveal complications, due to unusual mutations, secret adoptions, and non-paternity events (i.e., that the perceived father in a generation is not the father indicated by written birth records).[71] According to the Ancestry and Ancestry Testing Task Force of the American Society of Human Genetics, autosomal tests cannot detect "large portions" of DNA from distant ancestors because it has not been inherited.[72]

With the increasing popularity of the use of DNA tests for ethnicity tests, uncertainties and errors in ethnicity estimates are a drawback for Genetic genealogy. While ethnicity estimates at the continental level should be accurate (with the possible exception of East Asia and the Americas), sub-continental estimates, especially in Europe, are often inaccurate. Customers may be misinformed about the uncertainties and errors of the estimates.[73]

Some have recommended government or other regulation of ancestry testing to ensure its performance to an agreed standard.[74]

A number of law enforcement agencies took legal action to compel genetic genealogy companies to release genetic information that could match cold case crime victims[75] or perpetrators. A number of companies fought the requests.[76]

Common misunderstandings of genetics

[edit]

The popular consciousness of DNA testing and of DNA generally is subject to a number of misconceptions involving the reliability of testing, the nature of the connections with one's ancestors, the connection between DNA and personal traits, etc.[77]

Medical information

[edit]

Though genealogical DNA tests are not designed mainly for medical purposes, autosomal DNA tests can be used to analyze the probability of hundreds of heritable medical conditions,[78] albeit the result is complex to understand and may confuse a non-expert. 23andMe provides medical and trait information from their genealogical DNA test[79] and for a fee the Promethease web site analyses genealogical DNA test data from Family Tree DNA, 23andMe, or AncestryDNA for medical information.[80] Promethease, and its research paper crawling database SNPedia, has received criticism for technical complexity and a poorly defined "magnitude" scale that causes misconceptions, confusion and panic among its users.[81]

The testing of full MtDNA and YDNA sequences is still somewhat controversial as it may reveal even more medical information. For example, a correlation exists between a lack of Y-DNA marker DYS464 and infertility, and between mtDNA haplogroup H and protection from sepsis. Certain haplogroups have been linked to longevity in some population groups.[82][83] The field of linkage disequilibrium, unequal association of genetic disorders with a certain mitochondrial lineage, is in its infancy, but those mitochondrial mutations that have been linked are searchable in the genome database Mitomap.[84] Family Tree DNA's MtFull Sequence test analyses the full MtDNA genome[26] and the National Human Genome Research Institute operates the Genetic And Rare Disease Information Center[85] that can assist consumers in identifying an appropriate screening test and help locate a nearby medical center that offers such a test.

DNA testing for consumers

[edit]

The first company to provide direct-to-consumer genealogical DNA tests was the now defunct GeneTree. However, it did not offer multi-generational genealogy tests. In fall 2001, GeneTree sold its assets to Salt Lake City-based Sorenson Molecular Genealogy Foundation (SMGF) which originated in 1999.[86] While in operation, SMGF provided free Y-chromosome and mitochondrial DNA tests to thousands.[87] Later, GeneTree returned to genetic testing for genealogy in conjunction with the Sorenson parent company and eventually was part of the assets acquired in the Ancestry.com buyout of SMGF in 2012.[88][89]

In 2000, Family Tree DNA, founded by Bennett Greenspan and Max Blankfeld, was the first company dedicated to direct-to-consumer testing for genealogy research. They initially offered eleven-marker Y-Chromosome STR tests and HVR1 mitochondrial DNA tests. They originally tested in partnership with the University of Arizona.[90][91] [92][93] [94]

In 2007, 23andMe was the first company to offer a saliva-based direct-to-consumer genetic testing.[95] It was also the first to implement the use of autosomal DNA for ancestry testing, which other major companies (e.g., Ancestry, Family Tree DNA, and MyHeritage) now use.[96][97]

MyHeritage launched its genetic testing service in 2016, allowing users to use cheek swabs to collect samples.[98] In 2019, new analysis tools were presented: autoclusters (grouping all matches visually into clusters)[99] and family tree theories (suggesting conceivable relations between DNA matches by combining several Myheritage trees as well as the Geni global family tree).[100]

Living DNA, founded in 2015, also provides a genetic testing service. Living DNA uses SNP chips to provide reports on autosomal ancestry, Y, and mtDNA ancestry.[101][102] Living DNA provides detailed reports on ancestry from the UK as well as detailed Y chromosome and mtDNA reports.[103][104][105]

In 2019 it was estimated that large genealogical testing companies had about 26 million DNA profiles.[106][107] Many transferred their test result for free to multiple testing sites, and also to genealogical services such as Geni.com and GEDmatch. GEDmatch said in 2018 that about half of their one million profiles were from the USA.[107]

DNA in genealogy software

[edit]

Some genealogy software programs – such as Family Tree Maker, Legacy Family Tree (Deluxe Edition) and the Swedish program Genney – allow recording DNA marker test results. This allows for tracking of both Y-chromosome and mtDNA tests, and recording results for relatives.[108]

See also

[edit]

References

[edit]
  1. ^ Bettinger & Wayne (2016, p. 8)
  2. ^ a b c d e f "Understanding genetic ancestry testing". Molecular and Cultural Evolution Lab. University College London. 2016. Archived from the original on 7 April 2016. Retrieved 24 November 2016.
  3. ^ "Claims of connections, therefore, between specific uniparental lineages and historical figures or historical migrations of peoples are merely speculative." Royal, Charmaine D.; Novembre, John; Fullerton, Stephanie M.; Goldstein, David B.; Long, Jeffrey C.; Bamshad, Michael J.; Clark, Andrew G. (14 May 2010). "Inferring Genetic Ancestry: Opportunities, Challenges, and Implications". The American Journal of Human Genetics. 86 (5): 661–73. doi:10.1016/j.ajhg.2010.03.011. ISSN 0002-9297. PMC 2869013. PMID 20466090.
  4. ^ a b c d e Emery, Leslie S.; Magnaye, Kevin M.; Bigham, Abigail W.; Akey, Joshua M.; Bamshad, Michael J. (5 February 2015). "Estimates of Continental Ancestry Vary Widely among Individuals with the Same mtDNA Haplogroup". The American Journal of Human Genetics. 96 (2): 183–93. doi:10.1016/j.ajhg.2014.12.015. ISSN 0002-9297. PMC 4320259. PMID 25620206.
  5. ^ Bettinger & Wayne (2016, p. 70)
  6. ^ Bettinger & Wayne (2016, p. 68)
  7. ^ "Autosomal DNA – ISOGG Wiki". isogg.org. Retrieved 3 February 2017.
  8. ^ "Best Ancestry DNA Test 2018 – Which Testing Kit is Best & How to Choose". 10 January 2018.
  9. ^ "Concepts – Imputation". 5 September 2017.
  10. ^ "March – 2016 – DNAeXplained – Genetic Genealogy". dna-explained.com. 30 March 2016.
  11. ^ "The Danger of Distant Matches – The Genetic Genealogist". 6 January 2017.
  12. ^ "Cousin statistics – ISOGG Wiki". isogg.org.
  13. ^ Combs-Bennett, Shannon (3 December 2015). "How to Use AncestryDNA Shared Matches – Family Tree". Family Tree. Retrieved 30 April 2018.
  14. ^ Lassalle, Melody (15 March 2018). "MyHeritage DNA Ups Its Game with Updated Chromosome Browser". Genealogy Research Journal. Retrieved 30 April 2018.
  15. ^ Southard, Diahan (19 June 2017). "Triple Play: Triangulating Your DNA Matches – Family Tree". Family Tree. Retrieved 30 April 2018.
  16. ^ Bettinger & Wayne (2016, p. 107)
  17. ^ Bettinger & Wayne (2016, p. 114)
  18. ^ Bettinger & Wayne (2016, p. 111)
  19. ^ a b Westen, Antoinette A.; Kraaijenbrink, Thirsa; Robles de Medina, Elizaveta A.; Harteveld, Joyce; Willemse, Patricia; Zuniga, Sofia B.; van der Gaag, Kristiaan J.; Weiler, Natalie E.C.; Warnaar, Jeroen (May 2014). "Comparing six commercial autosomal STR kits in a large Dutch population sample". Forensic Science International: Genetics. 10: 55–63. doi:10.1016/j.fsigen.2014.01.008. PMID 24680126.
  20. ^ Ziętkiewicz, Ewa; Witt, Magdalena; Daca, Patrycja; Żebracka-Gala, Jadwiga; Goniewicz, Mariusz; Jarząb, Barbara; Witt, Michał (15 December 2011). "Current genetic methodologies in the identification of disaster victims and in forensic analysis". Journal of Applied Genetics. 53 (1): 41–60. doi:10.1007/s13353-011-0068-7. ISSN 1234-1983. PMC 3265735. PMID 22002120.
  21. ^ Sun, Hao; Zhou, Chi; Huang, Xiaoqin; Lin, Keqin; Shi, Lei; Yu, Liang; Liu, Shuyuan; Chu, Jiayou; Yang, Zhaoqing (8 April 2013). Caramelli, David (ed.). "Autosomal STRs Provide Genetic Evidence for the Hypothesis That Tai People Originate from Southern China". PLOS ONE. 8 (4): e60822. Bibcode:2013PLoSO...860822S. doi:10.1371/journal.pone.0060822. ISSN 1932-6203. PMC 3620166. PMID 23593317.
  22. ^ Guo, Yuxin; Chen, Chong; Xie, Tong; Cui, Wei; Meng, Haotian; Jin, Xiaoye; Zhu, Bofeng (13 June 2018). "Forensic efficiency estimate and phylogenetic analysis for Chinese Kyrgyz ethnic group revealed by a panel of 21 short tandem repeats". Royal Society Open Science. 5 (6): 172089. Bibcode:2018RSOS....572089G. doi:10.1098/rsos.172089. ISSN 2054-5703. PMC 6030347. PMID 30110484.
  23. ^ Norrgard, Karen (2008). "Forensics, DNA Fingerprinting, and CODIS". Nature Education. 1 (1): 35.
  24. ^ Bettinger & Wayne (2016, p. 9)
  25. ^ "mtDNA regions". Phylotree.org. Archived from the original on 27 July 2011. Retrieved 15 June 2011.
  26. ^ a b "Family Tree DNA Review". Top 10 DNA Tests. May 2018. Retrieved 19 May 2018.
  27. ^ Bettinger & Wayne (2016, p. 50)
  28. ^ Poznik GD, Henn BM, Yee MC, Sliwerska E, Euskirchen GM, Lin AA, Snyder M, Quintana-Murci L, Kidd JM, Underhill PA, Bustamante CD (August 2013). "Sequencing Y chromosomes resolves discrepancy in time to common ancestor of males versus females". Science. 341 (6145): 562–65. Bibcode:2013Sci...341..562P. doi:10.1126/science.1237619. PMC 4032117. PMID 23908239.
  29. ^ Fu Q, Mittnik A, Johnson PL, Bos K, Lari M, Bollongino R, Sun C, Giemsch L, Schmitz R, Burger J, Ronchitelli AM, Martini F, Cremonesi RG, Svoboda J, Bauer P, Caramelli D, Castellano S, Reich D, Pääbo S, Krause J (21 March 2013). "A revised timescale for human evolution based on ancient mitochondrial genomes". Current Biology. 23 (7): 553–59. Bibcode:2013CBio...23..553F. doi:10.1016/j.cub.2013.02.044. PMC 5036973. PMID 23523248.
  30. ^ Bettinger & Wayne (2016, p. 51)
  31. ^ Bettinger & Wayne (2016, p. 30)
  32. ^ "Matching Y-Chromosome DNA Results". Molecular Genealogy. Sorenson Molecular Genealogy Foundation. Archived from the original on 3 May 2015. Retrieved 15 June 2011.
  33. ^ Bettinger & Wayne (2016, p. 35)
  34. ^ Bettinger & Wayne (2016, p. 41)
  35. ^ Karmin; et al. (2015). "A recent bottleneck of Y chromosome diversity coincides with a global change in culture". Genome Research. 25 (4): 459–66. doi:10.1101/gr.186684.114. PMC 4381518. PMID 25770088. "we date the Y-chromosomal most recent common ancestor (MRCA) in Africa at 254 (95% CI 192–307) kya and detect a cluster of major non-African founder haplogroups in a narrow time interval at 47–52 kya, consistent with a rapid initial colonization model of Eurasia and Oceania after the out-of-Africa bottleneck. In contrast to demographic reconstructions based on mtDNA, we infer a second strong bottleneck in Y-chromosome lineages dating to the last 10 ky."
  36. ^ Mendez, L.; et al. (2016). "The Divergence of Neandertal and Modern Human Y Chromosomes". The American Journal of Human Genetics. 98 (4): 728–34. doi:10.1016/j.ajhg.2016.02.023. PMC 4833433. PMID 27058445.
  37. ^ Bettinger & Wayne (2016, p. 40)
  38. ^ Alsup, Blake (29 April 2019). "Ancestry.com update changes ethnicity of customers". NY Daily News.
  39. ^ Daalder, Marc (18 September 2018). "Ancestry.com changed how it determines ethnicity and people are upset". K5 News. Archived from the original on 30 September 2022. Retrieved 11 June 2019.
  40. ^ "mtDNA matches". Smgf.org. Archived from the original on 18 November 2008. Retrieved 15 June 2011.
  41. ^ a b Sykes, Bryan (2001). The Seven Daughters of Eve. W. W. Norton. ISBN 0-393-02018-5, pp. 291–92. Sykes discusses the difficulty in genealogically tracing a maternal lineage, due to the lack of matrilineal surnames (or matrinames).
  42. ^ Rutherford, Adam (24 May 2015). "So you're related to Charlemagne? You and every other living European…". The Guardian. Retrieved 8 February 2016.
  43. ^ "Patriclan: Trace Your Paternal Ancestry". African Ancestry. Archived from the original on 7 July 2011. Retrieved 15 June 2011.
  44. ^ Paul Heinegg, Free African Americans of Virginia, North Carolina, South Carolina, Maryland and Delaware[1], accessed 15 February 2008
  45. ^ Paul Heinegg, Free African Americans of Virginia, North Carolina, South Carolina, Maryland and Delaware, accessed 15 February 2008
  46. ^ "Native American | Definition of Native American by Merriam-Webster". www.merriam-webster.com. Retrieved 4 October 2016.
  47. ^ "AncestryDNA FAQ". www.ancestry.co.uk.
  48. ^ Hammer MF, Behar DM, Karafet TM, Mendez FL, Hallmark B, Erez T, Zhivotovsky LA, Rosset S, Skorecki K (November 2009). "Extended Y chromosome haplotypes resolve multiple and unique lineages of the Jewish priesthood". Human Genetics. 126 (5): 707–17. doi:10.1007/s00439-009-0727-5. PMC 2771134. PMID 19669163.
  49. ^ Mas, V. (2013). Y-DNA Haplogroup J1 phylogenetic tree. Figshare. doi:10.6084/m9.figshare.741212.
  50. ^ ftdna.com (kept uptodate). http://www.familytreedna.com/faq/answers/default.aspx?faqid=9#922 "FAQ: ...how should the genetic distance at 37 Y-chromosome STR markers be interpreted?" Retrieved 2012-01-13.
  51. ^ ftdna.com (kept uptodate). http://www.familytreedna.com/faq/answers/default.aspx?faqid=9#925 "FAQ: ...how should the genetic distance at 111 Y-chromosome STR markers be interpreted?" Retrieved 2012-01-13.
  52. ^ Randall, Caresa Alexander (16 November 2016). "Adopted man finds biological family with help of AncestryDNA". Deseret News. Archived from the original on 17 November 2016. Retrieved 30 April 2018.
  53. ^ ""Buckskin Girl" case: DNA breakthrough leads to ID of 1981 murder victim". CBS News. 12 March 2018. Retrieved 30 April 2018.
  54. ^ Augenstein, Seth (9 May 2018). "DNA Doe Project IDs 2001 Motel Suicide, Using Genealogy". Forensic Magazine. Retrieved 19 May 2018.
  55. ^ Zhang, Sarah (27 March 2018). "How a Genealogy Website Led to the Alleged Golden State Killer". The Atlantic. Retrieved 30 April 2018.
  56. ^ Green, Sara Jean (18 May 2018). "Investigators use DNA, genealogy database to ID suspect in 1987 double homicide". The Seattle Times. Retrieved 19 May 2018.
  57. ^ Regalado, Antonio. "Investigators searched a million people's DNA to find Golden State serial killer".
  58. ^ Lillis, Ryan; Kasler, Dale; Chabria, Anita (27 April 2018). "'Open-source' genealogy site provided missing DNA link to East Area Rapist, investigator says". The Sacramento Bee. Retrieved 27 April 2018.
  59. ^ Zhang, Sarah (19 May 2018). "The Coming Wave of Murders Solved by Genealogy". The Atlantic. Retrieved 19 May 2018.
  60. ^ Haag, Matthew (4 February 2019). "FamilyTreeDNA Admits to Sharing Genetic Data With F.B.I." The New York Times. ISSN 0362-4331. Retrieved 10 April 2019.
  61. ^ Augenstein, Seth (23 May 2019). "Forensic Genealogy: Where Does Cold-Case Breakthrough Technique Go After GEDmatch Announcement?". Forensic Magazine. Retrieved 24 May 2019.
  62. ^ Augenstein, Seth (24 May 2018). "Golden State Killer Backlash? Public Databases Shutting Down in Wake of Arrest". Forensic Magazine. Retrieved 24 May 2019.
  63. ^ Vergano, Dan (13 June 2013). "DNA detectives seek origins of you". USA Today. Retrieved 5 July 2016.
  64. ^ Estes, Roberta (30 December 2015). "23andMe, Ancestry and Selling Your DNA Information". DNAeXplained – Genetic Genealogy. Retrieved 5 July 2016.
  65. ^ Seife, Charles (27 November 2013). "23andMe Is Terrifying, but Not for the Reasons the FDA Thinks; The genetic-testing company's real goal is to hoard your personal data". Scientific American. Retrieved 5 July 2016.
  66. ^ Wallace SE, Gourna EG, Nikolova V, Sheehan NA (December 2015). "Family tree and ancestry inference: is there a need for a 'generational' consent?". BMC Medical Ethics. 16 (1): 87. doi:10.1186/s12910-015-0080-2. PMC 4673846. PMID 26645273.
  67. ^ Collins, Nick (17 March 2013). "DNA ancestry tests branded 'meaningless'". The Telegraph. Retrieved 5 July 2016.
  68. ^ Thomas, Mark (25 February 2013). "To claim someone has 'Viking ancestors' is no better than astrology". The Guardian. Retrieved 5 July 2016.
  69. ^ Reference (22 November 2016). "What is genetic ancestry testing?". Genetics Home Reference. U.S National Library of Medicine. Retrieved 24 November 2016.
  70. ^ "DNA doesn't lie!". 1 October 2017.
  71. ^ "Non-paternity event – ISOGG Wiki". isogg.org.
  72. ^ Harmon, Katherine (14 May 2010). "Genetic ancestry testing is an inexact science, task force says". Scientific American. Retrieved 5 July 2016.
  73. ^ Estes, Roberta (11 January 2017). "Concepts – Calculating Ethnicity Percentages". DNAeXplained - Genetic Genealogy.
  74. ^ Lee SS, Soo-Jin Lee S, Bolnick DA, Duster T, Ossorio P, Tallbear K (July 2009). "Genetics. The illusive gold standard in genetic ancestry testing". Science. 325 (5936): 38–39. doi:10.1126/science.1173038. PMID 19574373. S2CID 206519537.
  75. ^ O'Rourke, Ciara (16 August 2017). "Solving a Murder Mystery With Ancestry Websites". The Atlantic.
  76. ^ Robbins, Rebecca (28 April 2018). "The Golden State Killer Case Was Cracked with a Genealogy Web Site". Scientific American / STAT. Retrieved 30 April 2018.
  77. ^ Zimmer, Carl (2019). "Seven Big Misconceptions about Heredity". Skeptical Inquirer. 43 (3): 34–39. Archived from the original on 8 August 2019. Retrieved 8 August 2019.
  78. ^ "List of medical conditions – SNPedia". www.snpedia.com. Retrieved 27 June 2019.
  79. ^ "The Pros and Cons of the Main Autosomal DNA Testing Companies". The DNA Geek. 14 November 2016. Retrieved 19 May 2018.
  80. ^ Bettinger, Blaine (22 September 2013). "What Else Can I Do with My DNA Test Results?". The Genetic Genealogist. Retrieved 19 May 2018.
  81. ^ Arthur, Rob (20 January 2016). "What's in Your Genes? Some Companies Analyzing Your DNA Use Junk Science". Slate.
  82. ^ De Benedictis G, Rose G, Carrieri G, De Luca M, Falcone E, Passarino G, Bonafe M, Monti D, Baggio G, Bertolini S, Mari D, Mattace R, Franceschi C (September 1999). "Mitochondrial DNA inherited variants are associated with successful aging and longevity in humans". FASEB Journal. 13 (12): 1532–36. doi:10.1096/fasebj.13.12.1532. PMID 10463944. S2CID 8699708.
  83. ^ Rose, Giuseppina; Passarino, Giuseppe; Carrieri, Giuseppina; Altomare, Katia; Greco, Valentina; Bertolini, Stefano; Bonafè, Massimiliano; Franceschi, Claudio; De Benedictis, Giovanna (September 2001). "European Journal of Human Genetics (2001) 9, pp 701±707" (PDF). European Journal of Human Genetics. 9 (9): 701–707. doi:10.1038/sj.ejhg.5200703. PMID 11571560. S2CID 13730557.
  84. ^ "Mitomap". Mitomap. Retrieved 15 June 2011.
  85. ^ "Genetic And Rare Disease Information Center (GARD)". Genome.gov. 22 March 2011. Retrieved 15 June 2011.
  86. ^ "CMMG alum launches multi-million dollar genetic testing company" (PDF). Alum Notes. 17 (2). Wayne State University School of Medicine: 1. Spring 2006. Archived from the original (PDF) on 9 August 2017. Retrieved 24 January 2013.
  87. ^ "How Big Is the Genetic Genealogy Market?". The Genetic Genealogist. 6 November 2007. Retrieved 19 February 2009.
  88. ^ Dobush, Grace (12 July 2012). "Ancestry.com Acquisition Means Changes at GeneTree and SMGF.org". Family Tree. Archived from the original on 10 April 2019. Retrieved 10 April 2019.
  89. ^ "Ancestry.com Launches new AncestryDNA Service: The Next Generation of DNA Science Poised to Enrich Family History Research" (Press release). Archived from the original on 26 May 2013. Retrieved 1 July 2013.
  90. ^ Belli, Anne (18 January 2005). "Moneymakers: Bennett Greenspan". Houston Chronicle. Retrieved 14 June 2013. Years of researching his family tree through records and documents revealed roots in Argentina, but he ran out of leads looking for his maternal great-grandfather. After hearing about new genetic testing at the University of Arizona, he persuaded a scientist there to test DNA samples from a known cousin in California and a suspected distant cousin in Buenos Aires. It was a match. But the real find was the idea for Family Tree DNA, which the former film salesman launched in early 2000 to provide the same kind of service for others searching for their ancestors.
  91. ^ Ugo A. Perego; Ann Turner; Jayne E. Ekins; Scott R. Woodward (December 2005). "The Science of Molecular Genealogy". National Genealogical Society Quarterly. 93 (1–4). National Genealogical Society: 248. Businessman Bennett Greenspan hoped that the approach used in the Jefferson and Cohen research would help family historians. After reaching a brick wall on his mother's surname, Nitz, he discovered and Argentine researching the same surname. Greenspan enlisted the help of a male Nitz cousin. A scientist involved in the original Cohen investigation tested the Argentine's and Greenspan's cousin's Y chromosomes. Their haplotypes matched perfectly.
  92. ^ Lomax, John Nova (14 April 2005). "Who's Your Daddy?". Houston Press. Retrieved 14 June 2013. A real estate developer and entrepreneur, Greenspan has been interested in genealogy since his preteen days.
  93. ^ Dardashti, Schelly Talalay (30 March 2008). "When oral history meets genetics". The Jerusalem Post. Retrieved 14 June 2013. Greenspan, born and raised in Omaha, Nebraska, has been interested in genealogy from a very young age; he drew his first family tree at age 11.
  94. ^ Bradford, Nicole (24 February 2008). "Riding the 'genetic revolution'". Houston Business Journal. Retrieved 19 June 2013.
  95. ^ Hamilton, Anita (29 October 2008). "Best Inventions of 2008". Time. Archived from the original on 2 November 2008. Retrieved 5 April 2012.
  96. ^ "About Us". 23andMe. Archived from the original on 26 February 2018. Retrieved 11 February 2018.
  97. ^ Janzen, Tim; et al. "Family Tree DNA Learning Center". Autosomal DNA testing comparison chart. Gene by Gene. {{cite book}}: |website= ignored (help)
  98. ^ Lardinois, Frederic (7 November 2016). "MyHeritage launches DNA testing service to help you uncover your family's history". TechCrunch. Retrieved 13 December 2016.
  99. ^ "Introducing AutoClusters for DNA Matches". MyHeritage Blog. 28 February 2019.
  100. ^ "MyHeritage's "Theory of Family Relativity": An Exciting New Tool!". DanaLeeds.com. 15 March 2019.
  101. ^ "Living DNA review". 21 June 2019.
  102. ^ "Is this the most detailed at-home DNA testing kit yet?". CNN. 22 April 2019.
  103. ^ Durie, Bruce (January 2012). Scottish Genealogy (Fourth ed.). The History Press. ISBN 9780752488479.
  104. ^ "Comparing the 5 Major DNA Tests: Living DNA - Family Tree". www.familytreemagazine.com. Archived from the original on 2 August 2018.
  105. ^ "What I actually learned about my family after trying 5 DNA ancestry tests". 13 June 2018.
  106. ^ Regalado, Antonio (11 February 2019). "More than 26 million people have taken an at-home ancestry test". MIT Technology Review. Retrieved 10 April 2019.
  107. ^ a b Michaeli, Yarden (16 November 2018). "To Solve Cold Cases, All It Takes Is Crime Scene DNA, a Genealogy Site and High-speed Internet". Haaretz. Retrieved 21 November 2018.
  108. ^ Bettinger, Blaine (22 September 2013). "What Else Can I Do with My DNA Test Results?". The Genetic Genealogist. Retrieved 24 November 2016.

Sources

[edit]
  • Bettinger BT, Wayne DP (2016). Genetic Genealogy in Practice. Arlington, VA: National Genealogical Society. ISBN 978-1-935815-22-8.

Further reading

[edit]