(ページ「Genealogical DNA test」の翻訳により作成)
タグ: サイズの大幅な増減
== 消費者のためのDNA検査 ==
直接消費者にむけて系統DNA検査を提供した最初の会社は[[GeneTree]]だった。 しかし、それは多世代の系統検査を提供していなかった。2001年の秋、GeneTreeはソルトレイクシティの1999年に設立されたSorenson分子系譜財団 (SMGF)に資産を売却した。[<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 - Alum notes|publisher=Wayne State University, School of Medicine's alumni journal|volume=17|date=Spring 2006|page=1]|accessdate=24 Jan 2013|issue=2}}</ref> SMGFの稼働している間、Y染色体とミトコンドリアのDNA検査を無料で数千人に提供した。[2]<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|accessdate=19 Feb 2009}}</ref> その後、GeneTreeは親会社のSorensonとともに系統遺伝子検査の分野に戻ってきたが、最終的にSMGFを買収したAncestry.comの一部となった。[3]<ref name=SMGF2012>{{cite press release|url=http://corporate.ancestry.com/press/press-releases/2012/05/ancestry.com-dna-launches/|accessdate=1 July 2013|title=Ancestry.com Launches new AncestryDNA Service: The Next Generation of DNA Science Poised to Enrich Family History Research|deadurl=yes|archiveurl=https://web.archive.org/web/20130526104607/http://corporate.ancestry.com/press/press-releases/2012/05/ancestry.com-dna-launches/|archivedate=26 May 2013|df=}}</ref>
2000年には、Bennett GreenspanとMax Blankfeldによって設立された[[ファミリーツリーDNA]]が、消費者向けの系統検査を専門とする最初の会社だった。彼らは当初、アリゾナ大学と提携して、11マーカーのY染色体STR検査と、HVR1ミトコンドリアDNA検査を提供した。<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|accessdate=June 14, 2013|newspaper=Houston Chronicle|date=January 18, 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|title=National Genealogical Society Quarterly|volume=93|issue=1–4|publisher=National Genealogical Society|year=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>
2000年には、Bennett GreenspanとMax Blankfeldによって設立された[[ファミリーツリーDNA]]が、消費者向けの系統検査を専門とする最初の会社だった。彼らは当初、アリゾナ大学と提携して、11マーカーのY染色体STR検査と、HVR1ミトコンドリアDNA検査を提供した。[4][5][6][7][8]
<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/|accessdate=June 14, 2013|newspaper=Houston Press|date=April 14, 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|accessdate=June 14, 2013|newspaper=The Jerusalem Post|date=March 30, 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 Feb 2008|url=http://www.bizjournals.com/houston/stories/2008/02/25/smallb1.html?page=all|accessdate=19 June 2013}}</ref>
2007年には、 23andMeが初めて唾液による消費者向けの系統検査を提供した。<ref name = Time>{{Cite news|last=Hamilton|first=Anita|url=http://www.time.com/time/specials/packages/article/0,28804,1852747_1854493,00.html | title = Best Inventions of 2008 | work = [9[Time (magazine)|Time] ] | date=October 29, 2008 | accessdate = April 5, 2012}}</ref> また、今ではどこの主要な会社も提供している、autosomal DNAを元にした検査を初めて実用化した。[<ref>{{cite web |url=https://mediacenter.23andme.com/company/about-us/ |title=About Us |website=23andMe | accessdate = June 10][11], 2018}}</ref><ref>{{cite web |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 |author2=et al. | accessdate = June 10, 2018}}</ref>
2018年には、1200万人以上の人が系統の目的でDNA検査を行っていると推定され、その多くはアメリカで行われている。[<ref>{{Cite news|url=https://www.technologyreview.com/s/610233/2017-was-the-year-consumer-dna-testing-blew-up/|title=2017 was the year consumer DNA testing blew up|last=Regalado|first=Antonio|date=2018-02-12]|work=MIT Technology Review|access-date=2018-02-20|archive-url=|archive-date=|dead-url=|language=en}}</ref>
== 検査方法 ==
[[ファイル:Cotton-Swab-Cheek-090105-N-5681S-008.jpg|右|サムネイル|衛生兵が綿棒を使って、[[イオー・ジマ (LHD-7)]]に搭乗する兵士からDNAサンプルを採取する。]]
系統DNA検査はDNAサンプルに実施される。このDNAサンプルは、頬をこそぐ(buccal swab)、唾液を採取する、口をすすぐ、チューイングガムといった方法で採取できる。 &nbsp;通常、サンプル回収には23andMeや &nbsp;AncestryDNA、ファミリーツリーDNA、[[MyHeritage]]などのサービス提供会社のキットを用いる。キットの説明書に従いサンプルを採取したら、分析のため提供会社に返送する。
== 検査の種類 ==
系統DNA試験には3つの主要な種類: Autosomal([[常染色体]])・X-DNA、Y-DNA、およびmtDNAがある。
* '''常染色体''' &nbsp;1-22とXの染色体に注目する。常染色体(染色体1-22)は両親と近い祖先のすべてから継承する。X染色体は特別な継承パターンに従う。この検査には民族の推定によく用いられる。
* '''Y-DNA''' &nbsp;Y染色体に注目する。父から息子に継承されるため、男性が直接の父系を調べるために用いる。
* '''mtDNA''' &nbsp;ミトコンドリアに注目する。母から子へ継承されるため、直接の母系を調べるために用いる。[13]<ref>{{harvtxt|Bettinger|2016|p=8}}</ref>
Y-DNAおよびmtDNAは民族の推定に使用できないが、地理的に偏って分布するハプログループを知ることができる。<ref name=":0">{{cite web|url=https://www.ucl.ac.uk/mace-lab/debunking/understanding-testing|title=Understanding genetic ancestry testing|last=|first=|date=2016|website=Molecular and Cultural Evolution Lab|publisher=University College London|access-date=2016-11-24}}</ref> 消費者向けのDNA検査会社はよくハプログループに大陸や民族のラベル付けを行う(例えば、"アフリカのハプログループ"または"バイキングのハプログループ")。しかしこれらは不正確で誤解を招く恐れがある。<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|url=http://www.sciencedirect.com/science/article/pii/S0002929710001552|journal=The American Journal of Human Genetics|volume=86|issue=5|page=667|doi=10.1016/j.ajhg.2010.03.011|issn=0002-9297|via=|last1=Royal|first1=Charmaine D.|accessdate=2017-06-29}}</ref><ref name=":2" />
=== 常染色体DNA(atDNA)検査 ===
==== 何が検査されるか ====
常染色体DNAは、性別の決定に関与しない22対の染色体に含まれる。[14]<ref name=":0" /> 常染色体DNAは各世代で組み換えられ、新しい子孫は両親から染色体の対を受け取る<ref>{{harvtxt|Bettinger|2016|p=70}}</ref> これらは両親から正確に同じく継承し、また大まかに、祖父母から曾曾曾祖父まで等しく継承する。<ref>{{harvtxt|Bettinger|2016|p=68}}</ref> &nbsp;したがって、特定の祖先から受け継ぐマーカー(ゲノムの特定の部分にある変種、[[一塩基多型]]または[[SNP]]として知られる)の数は世代を経るごとに半減する。つまり、ある個人は両親それぞれから半数のマーカーを継承し、祖父母それぞれから約4分の1ずつ継承し、曾祖父母それぞれから約8分の1ずつ継承する。継承はもっとランダムで、遠い祖先ほど均等ではなくなる<ref>{{Cite web|url=http://isogg.org/wiki/Autosomal_DNA|title=Autosomal DNA – ISOGG Wiki|access-date=2017-02-03|website=isogg.org|language=en}}</ref> 一般的に、系統DNA検査はおよそ70万のSNPを検査する。<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|publisher= | accessdate = June 10, 2018}}</ref>
===== 塩基対の特定 =====
すべての主要なサービス提供者はIlluminaが提供する[[DNAマイクロアレイ|チップ]]を用いた装置を使用する。<ref>{{cite web|url=https://dna-explained.com/2017/09/05/concepts-imputation/|title=Concepts – Imputation|date=5 September 2017|publisher= | accessdate = June 10, 2018}}</ref> &nbsp;チップはどのSNP位置を検査するかを決定する。サービス提供者によって異なるバージョンのチップが使用される。 また、最新のバージョンのIlluminaチップは別のSNP位置の組を検査する。SNP位置と塩基対の一覧は「生データ」として顧客に提供される。生データはしばしば別のサービス提供者へアップロードされ、さらなる解釈と一致が行われる。さらなる解析のためデータはGEDmatch(サードパーティ製のwebベースのツールで、元のサービスプロバイダからの生データを解析する)にアップロードされることもある。
===== 一致の識別 =====
常染色体DNA検査の主要な機能は他の個人とのマッチングだ。 個人の検査されたSNPは過去に検査を受けた人のデータとともに企業のデータベースにあるため、ゲノムの中に共有するセグメントがあるかを推定できる。<ref>{{cite web|url=https://dna-explained.com/2016/03/|title=March - 2016 - DNAeXplained – Genetic Genealogy|website=dna-explained.com | accessdate = June 10, 2018}}</ref> &nbsp;一致するセグメントが検査会社の決めるしきい値より長い場合、マッチしていると考える。塩基対の特定とは異なり、新しく検査されたサンプルのデータや、マッチを決定するアルゴリズムは、独占的で各々の会社で独自のものである。
DNAセグメントの単位は &nbsp;centimorgan (cM)を用いる。 比較のため、ヒトゲノムは約6500cMである。一致する長さが短いほどマッチが誤りである可能性が高くなる。<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|publisher= | accessdate = June 10, 2018}}</ref> &nbsp;以降の解釈で重要となるのは共有するDNAの長さ(あるいは共有するゲノムの比率)である。
===== 常染色体マッチの解釈 =====
=== X染色体DNA検査 ===
X染色体SNPの結果が常染色体DNA検査に含まれることもある。男性も女性も母からX染色体を受け継ぐが、女性のみ2つ目のX染色体を父から受け継ぐ。<ref>{{Harvtxt|Bettinger|2016|p=107}}</ref> X染色体は特別な継承パターンを持ち、atDNAよりも祖先候補を大きく絞り込むのに有用である。例えばある男性とX染色体の一致が見られた場合、それは母系の側から来たことがわかる。<ref>{{Harvtxt|Bettinger|2016|p=114}}</ref> &nbsp;常染色体DNAのように、X染色体DNAも各世代でランダムな組み換えが起こる(ただし父から娘へのX染色体は変化せずに引き継がれる)。男性と女性とで可能なX染色体DNAの継承パターンを表した専用のチャートがある。<ref>{{Harvtxt|Bettinger|2016|p=111}}</ref>
=== STR ===
=== ミトコンドリアDNA(mtDNA)の検査 ===
ミトコンドリアはヒト細胞の一部で、それ自身のDNAを持っている。ミトコンドリアDNAの多くは16,569塩基対(追加または削除変異で数は多少異なる)<ref>{{harvtxt|Bettinger|2016|p=9}}</ref> &nbsp;を持ち、ヒトゲノムDNAの32億塩基対に比べるとかなり少ない。 ミトコンドリアDNAは母から子に伝達されるため、 &nbsp;[[ミトコンドリアDNA|mtDNA]]を用いて直接の母系の祖先を追うことができる。伝達の際にゲノムDNAより比較的まれな確率で変異が起こる。他人とmtDNAが完全に一致した場合、1代前から50代前の間の祖先を共有しているといえる。  &nbsp;&nbsp;もっと離れたハプログループやサブクレードの一致は、共通の地理的な故郷と結びつけられる。
父からのmtDNA伝達の有無については議論の余地がある。父からのmtDNA伝達によりmtDNA検査は無効だと主張する人もいる。<ref>[http://www.springerlink.com/content/mv5812037q10u886/ M. Pickford, "Paradise lost: Mitochondrial eve refuted"]. SpringerLink, July 2006</ref> しかし、その他の研究は父から子孫へのmtDNA伝達は起こらないとしており、<ref>e.g. {{cite journal|date=November 1980|title=Maternal inheritance of human mitochondrial DNA|url=http://www.pnas.org/content/77/11/6715.abstract|journal=Proc. Natl. Acad. Sci. USA|volume=77|issue=11|pages=6715–19|bibcode=1980PNAS...77.6715G|doi=10.1073/pnas.77.11.6715|pmid=6256757|pmc=350359|vauthors=Giles RE, Blanc H, Cann HM, Wallace DC}}</ref> &nbsp;それが系統mtDNA検査を利用することの根拠となるだろう。
==== 何が検査されるか ====
mtDNAは現在の慣習で次の3つの領域に分けられる。コード領域(00577-16023)、超可変領域 (HVR1[16024-16569]、HVR2[00001-00576")。<ref>{{cite web|url=http://www.phylotree.org/rCRS_annotated.htm|title=mtDNA regions|accessdate=2011-06-15|date=|work=Phylotree.org|archiveurl=https://web.archive.org/web/20110727174043/http://www.phylotree.org/rCRS_annotated.htm|archivedate=27 July 2011|deadurl=yes|df=dmy}}</ref>
最も一般的なmtDNA検査は、HVR1とHVR2のシーケンス、あるいはミトコンドリア全体のシーケンスを検査する。一般的には、HVRのみの検査は系統研究の用途に限られるが、そのため全体シーケンスに比べてますます人気かつ手軽な方法となっている。mtDNA全体シーケンスは主要な検査会社の中ではファミリーツリーDNAだけが提供しており<ref name=":3">{{Cite web|url=https://www.top10dnatests.com/reviews/family-tree-dna-review/|title=Family Tree DNA Review|access-date=2018-05-19|last=|first=|date=May 2018|website=Top 10 DNA Tests|language=en-US|archive-url=|archive-date=|dead-url=}}</ref> &nbsp;、またコード領域のDNAは被験者の医学的な情報を明らかにするため物議をかもしている。<ref>{{harvtxt|Bettinger|2016|p=50}}</ref>
==== ハプログループ ====
==== mtDNAの検査結果を理解する ====
検査結果がそれぞれの塩基の結果一覧として与えられることは少ない。かわりに、Cambridge Reference Sequence(CRS)との比較した結果を受け取るのが一般的だ。これは1981年に初めてmtDNAを公開した(そして1999年に改訂された)あるヨーロッパ人のミトコンドリアである。<ref>{{harvtxt|Bettinger|2016|p=51}}</ref> &nbsp;CRSと被験者の間の差異は非常に小さいのが普通なので、塩基対それぞれを検査した生の結果一覧よりは扱いやすい。
; 例
==== mtDNAのニュース ====
mtDNA試験は、2012年9月に[[レスター大学]] 考古学者たちが &nbsp;[[リチャード3世 (イングランド王)|リチャード3世]]の遺骸を鑑定するために用いられた。<ref>{{cite web|url=http://www.dnacenter.com/blog/dna-tests-prove-that-the-body-found-under-a-parking-lot-belongs-to-king-richard-iii-but-was-he-truly-a-hunchback/|title=DNA Tests prove that the body found under a parking lot belongs to King Richard III; but was he truly a "hunchback?"|date=7 February 2013|publisher=DNA Diagnostics Center|archiveurl=https://web.archive.org/web/20141103225418/http://www.dnacenter.com/blog/dna-tests-prove-that-the-body-found-under-a-parking-lot-belongs-to-king-richard-iii-but-was-he-truly-a-hunchback/|archivedate=3 November 2014|deadurl=yes|df=dmy}}</ref>
=== Y染色体(Y-DNA)検査 ===
Y染色体はヒト染色体の23番目の対の1つである。Y染色体は男性のみが持ち、女性は23番目の対にX染色体を2つ持つ。Y染色体は父親から息子へほとんど変化せず引き継がれるため、Y染色体(Y-DNA)を用いて男性の父系の祖先を追うことができる。<ref name=":1">{{harvtxt|Bettinger|2016|p=30}}</ref> &nbsp;ある人の検査結果は別の人の結果と比較され、二人が共有する[[最もの共通祖先]](Most Recent Common Ancestor, MRCA)がいた年代を決定する。もし検査結果が非常に近ければ、系統的に有意な関係があるといえる。<ref>{{cite web|url=http://www.smgf.org/pages/yinterpretation.jspx|title=Matching Y-Chromosome DNA Results|accessdate=2011-06-15|work=Molecular Genealogy|publisher=Sorenson Molecular Genealogy Foundation|archiveurl=https://web.archive.org/web/20150503170935/http://www.smgf.org/pages/yinterpretation.jspx|archivedate=3 May 2015|deadurl=unfit}}CS1 maint: Unfit url ([//en.wikipedia.org/wiki/Category:CS1_maint:_Unfit_url link])
[[Category:CS1 maint: Unfit url]]</ref> surname project &nbsp;ではY染色体がマッチした多くの人が共通の祖先を見つけるために協力している。
[[ファイル:World_Map_of_Y-DNA_Haplogroups.png|右|サムネイル|340x340ピクセル|Dominant Y-chromosome haplogroups in pre-colonial world populations, with possible migrations routes according to the Coastal Migration Model.]]
[[一塩基多型]](SNP) はDNAシーケンスの1核酸の変化である。一般的なY-DNA SNP検査ではおよそ20,000 から 35,000の SNPを検査する。<ref>{{harvtxt|Bettinger|2016|p=41}}</ref> &nbsp;SNP検査を受けることで、STRよりも高精度の結果が得られる。2人の個人の関係について追加の情報を得るために、またハプログループを確かめるために検査が行われる。
新しいサブクレードが発見されるのは、個人、とくにヨーロッパ人以外が検査を受けたときである。最も重要な発見は2013年の &nbsp;[[ハプログループA (Y染色体)|haplogroup A00]] &nbsp;である。これによりY染色体アダムについての理論は大きな改訂を必要とされた。このハプログループが発見されたのは、あるアフリカ系アメリカ人がファミリーツリーDNAでSTR検査を行い、結果が他と違うと分かったときだった。彼がそれまでの「元」Y染色体アダムの子孫でないことがSNP検査により確認され、より古い男性がY染色体アダムになった。
=== DNA検査結果の利用 ===
===Using DNA test results===
{{Main|Genetic genealogy}}
====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 their accuracies have since improved greatly.{{Citation needed|date=April 2018}} Usually the results at the continental level are accurate, but more specific assertions of the test may turn out to be incorrect. For example, Europeans often receive an exaggerated proportion of Scandinavian.<ref>{{cite web|url=https://dna-explained.com/2016/02/10/ethnicity-testing-a-conundrum/|title=Ethnicity Testing – A Conundrum|date=10 February 2016|publisher=}}</ref> Testing companies will often regularly update their ethnicity estimate, changing an individual's ethnicity estimate.
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===
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 |date= |accessdate=2011-06-15}}</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===
[[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|accessdate=8 February 2016|publisher=Guardian|date=24 May 2015}}</ref>
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|url=http://www.sciencedirect.com/science/article/pii/S0002929714005217|journal=The American Journal of Human Genetics|volume=96|issue=2|pages=183–93|doi=10.1016/j.ajhg.2014.12.015|issn=0002-9297|last1=Emery|first1=Leslie S.|accessdate=2016-01-24}}</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" />
====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 |date= |accessdate=2011-06-15 |deadurl=yes |archiveurl=https://web.archive.org/web/20110707092826/http://www.africanancestry.com/patriclan.html |archivedate=7 July 2011 |df=dmy }}</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>
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.
====United States – Melungeon testing====
{{Main|Melungeon DNA Project}}
[[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====
{{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|last=|first=|date=|website=www.merriam-webster.com|publisher=|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====
{{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.
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>
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 journal | last1 = Mas | first1 = V. | year = 2013 | title = Y-DNA Haplogroup J1 phylogenetic tree | journal = | volume = | issue = | pages = | publisher = | jstor = | doi = 10.6084/m9.figshare.741212 | url = https://dx.doi.org/10.6084/m9.figshare.741212 | accessdate = }}</ref>
====European testing====
{{Further|Genetic history of Europe}}
For people with [[Europe]]an maternal ancestry, mtDNA tests are offered to determine which of eight European maternal "clans" the direct-line maternal ancestor belonged to. This mtDNA haplotype test was popularized in the book ''[[The Seven Daughters of Eve]]''.
{{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>
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 />
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|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|language=en}}</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|last=|first=|date=2018-03-12|work=CBS News|access-date=2018-04-30|language=en}}</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|language=en}}</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|language=en-US}}</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|language=en-US}}</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|publisher=}}</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=April 27, 2018|work=[[The Sacramento Bee]]|access-date=April 27, 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|language=en-US}}</ref>
Common concerns about genealogical DNA testing are cost and privacy issues.<ref>{{cite web|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|publisher=USA Today|access-date=2016-07-05}}</ref> Some testing companies<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 web|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|publisher=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 | url = https://dx.doi.org/10.1186/s12910-015-0080-2 }}</ref>
Autosomal DNA tests can identify relationships with good accuracy out to about 2nd cousin,<ref>{{cite web|url=https://www.ucl.ac.uk/mace-lab/debunking/understanding-testing|title=Understanding genetic ancestry testing|website=www.ucl.ac.uk}}</ref> but they have limitations.<ref>{{cite web|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|publisher=The Telegraph|access-date=2016-07-05}}</ref><ref>{{cite web|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|website=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|first=|date=2016-11-22|website=Genetics Home Reference|publisher=U.S National Library of Medicine|access-date=2016-11-24}}</ref> In particular, transplants of stem cell or bone marrow will produce matches with the donor. In addition, identical twins (who have identical DNA) will share higher amounts of DNA with a greater range of relatives.<ref>{{cite web|url=https://www.legalgenealogist.com/2017/10/01/dna-doesnt-lie/|title=DNA doesn't lie!|date=1 October 2017|publisher=}}</ref>
Testing of the Y-DNA lineage from father to son may reveal complications, due to unusual mutations, secret adoptions, and false paternity (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 web|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|publisher=Scientific American|access-date=2016-07-05}}</ref>
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>[https://dna-explained.com/2017/01/11/concepts-calculating-ethnicity-percentages/#comments Concepts – Calculating Ethnicity Percentages, ''DNA Explained'']</ref>
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 | language = en | journal = Science | volume = 325 | issue = 5936 | pages = 38–39 | date = July 2009 | pmid = 19574373 | doi = 10.1126/science.1173038 | url = http://science.sciencemag.org/content/325/5936/38 }}</ref>
A number of law enforcement agencies attempted to coerce
genetic genealogy companies that store customer's data into giving up information on their customers who could match [[cold case]] crime victims<ref>{{cite web|url=https://www.theatlantic.com/science/archive/2017/08/jane-doe-murder-ancestry/536916/|title=Solving a Murder Mystery With Ancestry Websites|first=Ciara|last=O'Rourke|publisher=}}</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|language=en}}</ref>
==Medical information==
Though genealogical DNA test results in general have no informative medical value and are not intended to determine genetic diseases or disorders, a correlation exists between a lack of [[List of Y-STR markers#DYS464|DYS464]] markers 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}}</ref><ref>{{cite web|url=https://www.nature.com/articles/5200703.pdf?origin=ppub|title=European Journal of Human Genetics (2001) 9, pp 701±707|publisher=}}</ref> 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|language=en-US}}</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|language=en-US}}</ref>
The testing of full mtDNA sequences is still somewhat controversial as it may reveal medical information. 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 |date= |accessdate=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 |accessdate=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.
==DNA in genealogy software==
Some{{which|date=January 2018}} [[Comparison of genealogy software|genealogy software]] programs allow recording DNA marker test results, allowing 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> DNA-family tree wall charts are available.
== See also ==
{{Portal|Molecular Anthropology}}
{{main|List of genetic genealogy topics}}
{{Div col|colwidth=30em}}
* [[Ancestry.com]]
* [[Archaeogenetics]]
* [[DNA paternity testing]]
* [[Electropherogram]]
* [[Family name]] (Patrilineal surname)
* [[Genetic fingerprinting]]
* [[Genetic genealogy]]
* [[Genetic Information Nondiscrimination Act]]
* [[Genographic Project|National Geographic Geno 2.0]]
* [[Human genetic clustering]]
* [[International HapMap Project]]
* [[International Society of Genetic Genealogy]]
* [[List of DNA tested mummies]]
* [[MyHeritage]]
{{div col end}}
== 関連項目 ==
* [[ジェノグラフィック・プロジェクト]]
== 参考文献 ==