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Not necessarily a contemporary of "Y-chromosomal Adam": “Not impossible “ is a better way of putting it — still very unlikely, even though the ranges overlap, as the overlap is big relative to human lifetime
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{{Short description|Matrilineal most recent common ancestor of all living humans}}
A comparison of the [[mitochondrial DNA]] of humans from many races and regions suggests that all of these DNA sequences have [[molecular evolution|evolved molecularly]] from a common ancestor sequence. Under the assumption that an individual inherits mitochondria only from his or her mother, this finding implies that all living humans descend from one woman--possibly one pre-human woman--who researchers have dubbed '''Mitochondrial Eve'''. Based on the [[molecular clock]] technique, Eve is believed to have lived roughly 150 000 years ago.
{{Use dmy dates|date=February 2023}}
{{Infobox haplogroup
|map= Early_diversification.PNG
|name= L
|origin-date= {{circa}} 100–230 [[Year#Abbreviations yr and ya|kya]]{{efn|group=note|"the synonymous mutation rate of Kivisild et al. [...] estimates the coalescence time of the mtDNA tree overall at ~160,000 kya [...] We present a revised chronology using the complete mtDNA genome rate and an ML approach for the mtDNA tree in Figure 6, with full details of the age estimates and associated 95% confidence regions in Table S5."<ref name="Soares09"/> See: [https://www.cell.com/cms/10.1016/j.ajhg.2009.05.001/attachment/dd25d63b-7e0f-4377-8e79-900694228888/mmc1.pdf Supplemental Data.]}}{{efn|group=note|"we estimate the time to the most recent common ancestor (TMRCA) of the Y chromosome to be 120 to 156 thousand years and the mitochondrial genome TMRCA to be 99 to 148 thousand years. Our findings suggest that, contrary to previous claims, male lineages do not coalesce significantly more recently than female lineages."<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 | display-authors = 6 | title = Sequencing Y chromosomes resolves discrepancy in time to common ancestor of males versus females | journal = Science | volume = 341 | issue = 6145 | pages = 562–565 | date = August 2013 | pmid = 23908239 | pmc = 4032117 | doi = 10.1126/science.1237619 | bibcode = 2013Sci...341..562P }}</ref>}}
|origin-place= East Africa
|ancestor= n/a
|descendants= [[Human mitochondrial DNA haplogroup|Mitochondrial macro-haplogroups]] [[Haplogroup L0|L0]], [[Haplogroup L1 (mtDNA)|L1]], and [[Haplogroup L5 (mtDNA)|L5]]
|mutations= None
}}


In [[human genetics]], the '''Mitochondrial Eve''' (more technically known as the '''Mitochondrial-Most Recent Common Ancestor''', shortened to '''mt-Eve''' or '''mt-MRCA''') is the [[Matrilineality|matrilineal]] [[most recent common ancestor]] (MRCA) of all [[world population|living]] humans. In other words, she is defined as the most recent woman from whom all living humans descend in an unbroken line purely through their mothers and through the mothers of those mothers, back until all lines converge on one woman.
Eve was not the sole living female of her day. Researchers believe as many as 20 000 individuals of Eve's species may have lived at the same time as her. But of the females of her day, only Eve produced an unbroken line of daughters that persists today. This is assumed to be an effect of chance rather than [[selection]]. Essentially, the hypothesized process by which all lineages but one disappear is the same as [[genetic drift]]. As with genetic drift, the process is much slower and much less likely to reach completion in a large population than in a [[small population size|small one]]. If Eve had lived among a million or a billion other females, it is very unlikely that ''all'' humans alive today could trace their descent to Eve (or to one female contemporary of Eve's).


In terms of [[Human mitochondrial DNA haplogroup|mitochondrial haplogroups]], the mt-MRCA is situated at the divergence of [[Macro-haplogroup L (mtDNA)|macro-haplogroup L]] into [[Haplogroup L0|L0]] and [[Haplogroup L1 (mtDNA)#Origin|L1–6]]. As of 2013, estimates on the age of this split ranged at around 155,000 years ago,{{efn|group=note|Two studies published in 2013 had 95% confidence intervals barely overlapping in the neighbourhood of 15 ka, a third study had a 95% confidence interval intermediate between the two others: "99 to 148 ka" according to Poznik, 2013<ref name=poz /> (ML whole-mtDNA age estimate: 178.8 [155.6; 202.2], ρ whole-mtDNA age estimate: 185.2 [153.8; 216.9], ρ synonymous age estimate: 174.8 [153.8; 216.9]), "134 to 188 ka", according to Fu, 2013,<ref name=Fu2013 /> and 150 to 234 ka (95% CI) from Soares, 2009.<ref name="Soares09" />}} consistent with a date later than the [[speciation]] of ''[[Homo sapiens]]'' but earlier than the [[Recent African origin of modern humans|recent out-of-Africa dispersal]].<ref>{{cite journal | vauthors = Endicott P, Ho SY, Metspalu M, Stringer C | title = Evaluating the mitochondrial timescale of human evolution | journal = Trends in Ecology & Evolution | volume = 24 | issue = 9 | pages = 515–521 | date = September 2009 | pmid = 19682765 | doi = 10.1016/j.tree.2009.04.006 }}</ref><ref name="Soares09"/><ref>{{cite web|url= https://www.leeds.ac.uk/news/article/245/new_molecular_clock_aids_dating_of_human_migration_history |publisher=University of Leeds |title=New 'molecular clock' aids dating of human migration history |date=3 June 2009 |access-date=23 December 2019}}</ref>
The observation that the mitochondria of living humans point to a common ancestor represents evidence that this ancestor lived in a much smaller breeding pool than humans live in today. This may be because the population in Eve's day passed through a [[population bottleneck|bottleneck]], or it may be that Eve lived only shortly after the migration or other isolation event that led to human [[speciation]]. Of the ancient human and [[hominid]] remains discovered so far, the oldest matching the bones of modern humans date from around the time that Eve lived.


The male analog to the "Mitochondrial Eve" is the "[[Y-chromosomal Adam]]" (or Y-MRCA), the individual from whom all living humans are [[Patrilineality|patrilineally]] descended. As the identity of both matrilineal and patrilineal MRCAs is dependent on genealogical history ([[pedigree collapse]]), they need not have lived at the same time. As of 2015, estimates of the age of the Y-MRCA range around 200,000 to 300,000 years ago, roughly consistent with the emergence of anatomically modern humans.<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. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males."</ref>
On the other hand, the most recent common ancestor to father an unbroken line of males, "[[Y-chromosome Adam]]," appears to have lived only about half as long ago as Eve. This means that another bottleneck event besides the one surrounding Eve affected the human lineage after her. The fact that the bottleneck in Adam's day appears not to have produced also a matrilineal ancestor of all living humans--a more recent Eve, in other words--illustrates that the branching and disappearance of lineages depends on chance.


The name "Mitochondrial Eve" alludes to the biblical [[Eve]], which has led to repeated misrepresentations or misconceptions in journalistic accounts on the topic. [[Popular science]] presentations of the topic usually point out such possible misconceptions by emphasizing the fact that the position of mt-MRCA is neither fixed in time (as the position of mt-MRCA moves forward in time as [[mitochondrial DNA]] (mtDNA) lineages become extinct), nor does it refer to a "first woman", nor the only living female of her time, nor the first member of a "new species".{{efn|group=note|"Caution: This does not make Mitochondrial Eve the first woman, or the first human, or the first member of a new species. Further Caution: This does not mean that other women alive when Eve was do not have descendants today; they simply do not have living descendants who are descended only through female links. Yet Further Caution: If a person were to be discovered whose mtDNA showed a pattern of mutations of greater time depth, then the status of Mitochondrial Eve would be reassigned to the most recent female ancestor shared by both that person and the person we now call Mitochondrial Eve."<ref>{{cite web |url= http://pages.ucsd.edu/~dkjordan/resources/clarifications/MitochondrialEve.html |title=Jordan: 'Mitochondrial Eve' |work=weber.ucsd.edu |year=2011 |access-date=7 January 2012}}</ref>}}
A recent challenge to the Eve theory has been the observation that the mitochondria of sperm are sometimes passed to offspring. Mitochondria may not be so pure a matrilineal marker as they were supposed when the theory was advanced.


==History==
Note that the concept of mitochondrial Eve is different from that of "[[African Eve]]," although [[anthropology|anthropologists]] have hypothesized a connection.
{{Human timeline}}


===Early research===
The [[Japan|Japanese]] [[horror]] [[film]] and [[novel]] ''Parasite Eve'' use the Mitochondrial Eve theory as the basis for a fantasy about a scientist bringing his dead wife back by regenerating her liver cells, with disastrous effects.
Early research using [[molecular clock]] methods was done during the late 1970s to early 1980s. [[Allan Wilson (biologist)|Allan Wilson]], [[Mark Stoneking]], [[Rebecca L. Cann]] and Wesley Brown found that [[mutation]] in human mtDNA was unexpectedly fast, at 0.02 substitution per base (1%) in a million years, which is 5–10 times faster than in [[nuclear DNA]].<ref>{{cite journal | vauthors = Brown WM, George M, Wilson AC | title = Rapid evolution of animal mitochondrial DNA | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 76 | issue = 4 | pages = 1967–1971 | date = April 1979 | pmid = 109836 | pmc = 383514 | doi = 10.1073/pnas.76.4.1967 | doi-access = free | bibcode = 1979PNAS...76.1967B }}</ref> Related work allowed for an analysis of the evolutionary relationships among gorillas, [[Pan (genus)|chimpanzee]]s ([[common chimpanzee]] and [[bonobo]]) and humans.<ref>{{cite journal | vauthors = Ferris SD, Wilson AC, Brown WM | title = Evolutionary tree for apes and humans based on cleavage maps of mitochondrial DNA | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 78 | issue = 4 | pages = 2432–2436 | date = April 1981 | pmid = 6264476 | pmc = 319360 | doi = 10.1073/pnas.78.4.2432 | doi-access = free | bibcode = 1981PNAS...78.2432F }}</ref> With data from 21 human individuals, Brown published the first estimate on the age of the mt-MRCA at 180,000 years ago in 1980.<ref>{{cite journal | vauthors = Brown WM | title = Polymorphism in mitochondrial DNA of humans as revealed by restriction endonuclease analysis | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 77 | issue = 6 | pages = 3605–3609 | date = June 1980 | pmid = 6251473 | pmc = 349666 | doi = 10.1073/pnas.77.6.3605 | doi-access = free | bibcode = 1980PNAS...77.3605B }}</ref> A statistical analysis published in 1982 was taken as evidence for [[recent African origin]] (a hypothesis which at the time was competing with Asian origin of ''H. sapiens'').<ref name=Cann82>{{cite journal | vauthors = Cann RL, Brown WM, Wilson AC | title = Evolution of human mitochondrial DNA: a preliminary report | journal = Progress in Clinical and Biological Research | volume = 103 Pt A | issue = Pt A | pages = 157–165 | year = 1982 | pmid = 6298804 }}</ref><ref>{{cite journal | vauthors = Cann RL, Wilson AC | title = Length mutations in human mitochondrial DNA | journal = Genetics | volume = 104 | issue = 4 | pages = 699–711 | date = August 1983 | pmid = 6311667 | pmc = 1202135 | doi = 10.1093/genetics/104.4.699 }}</ref><ref name="git" />


===1987 publication===
''See also:'' [[Y-chromosome Adam]]--[[neutral theory of molecular evolution]]--[[mitochondrial genome]] -- [[human evolution]] -- [[single origin theory]].
By 1985, data from the mtDNA of 145 women of different populations, and of two [[cell lines]], [[HeLa]] and GM 3043, derived from an African American and a [[ǃKung people|ǃKung]] respectively, were available. After more than 40 revisions of the draft, the manuscript was submitted to [[Nature (journal)|''Nature'']] in late 1985 or early 1986<ref name="git">{{cite journal | vauthors = Cann R | title = All about mitochondrial eve: an interview with Rebecca Cann. Interview by Jane Gitschier | journal = PLOS Genetics | volume = 6 | issue = 5 | pages = e1000959 | date = May 2010 | pmid = 20523888 | pmc = 2877732 | doi = 10.1371/journal.pgen.1000959 | doi-access = free }}</ref> and published on 1 January 1987. The published conclusion was that all current human mtDNA originated from a single population from Africa, at the time dated to between 140,000 and 200,000 years ago.<ref name="pmid3025745">{{cite journal | vauthors = Cann RL, Stoneking M, Wilson AC | title = Mitochondrial DNA and human evolution | journal = Nature | volume = 325 | issue = 6099 | pages = 31–36 | year = 1987 | pmid = 3025745 | doi = 10.1038/325031a0 | s2cid = 4285418 | bibcode = 1987Natur.325...31C }}</ref>

The dating for "Eve" was a blow to the [[multiregional hypothesis]], which was debated at the time, and a boost to the theory of the [[recent African origin of modern humans|recent origin model]].<ref name="pmid1840702">{{cite journal | vauthors = Vigilant L, Stoneking M, Harpending H, Hawkes K, Wilson AC | title = African populations and the evolution of human mitochondrial DNA | journal = Science | volume = 253 | issue = 5027 | pages = 1503–1507 | date = September 1991 | pmid = 1840702 | doi = 10.1126/science.1840702 | bibcode = 1991Sci...253.1503V }}</ref>

Cann, Stoneking and Wilson did not use the term "Mitochondrial Eve" or even the name "Eve" in their original paper. It is however used by Cann in an article entitled "In Search of Eve" in the September–October 1987 issue of ''The Sciences''.<ref>{{cite journal| vauthors = Cann RL |year=1987|title=In Search of Eve|url=https://onlinelibrary.wiley.com/doi/abs/10.1002/j.2326-1951.1987.tb02967.x|journal=The Sciences|language=en|volume=27|issue=5|pages=30–37|doi=10.1002/j.2326-1951.1987.tb02967.x|issn=2326-1951}}</ref> It also appears in the October 1987 article in [[science (journal)|''Science'']] by [[Roger Lewin]], headlined "The Unmasking of Mitochondrial Eve".<ref name=lew>{{cite journal | vauthors = Lewin R | title = The unmasking of mitochondrial Eve | journal = Science | volume = 238 | issue = 4823 | pages = 24–26 | date = October 1987 | pmid = 3116666 | doi = 10.1126/science.3116666 | bibcode = 1987Sci...238...24L }}</ref> The biblical connotation was very clear from the start. The accompanying research news in ''Nature'' had the title "Out of the garden of Eden".<ref>{{cite journal | vauthors = Wainscoat J | title = Human evolution. Out of the garden of Eden | journal = Nature | volume = 325 | issue = 6099 | pages = 13 | year = 1987 | pmid = 3796736 | doi = 10.1038/325013a0 | s2cid = 13187170 | bibcode = 1987Natur.325...13W | doi-access = free }}</ref>

Wilson himself preferred the term "Lucky Mother"<ref>{{cite web|url= https://io9.gizmodo.com/the-scientists-behind-mitochondrial-eve-tell-us-about-t-5879991 | vauthors = Wilkins A |date=27 January 2012 |title=The scientists behind Mitochondrial Eve tell us about the 'lucky mother' who changed human evolution forever |work=Gizmodo |access-date=23 December 2019}}</ref> and thought the use of the name Eve "regrettable".<ref name=lew/><ref>{{cite book| vauthors = Cann RL |year=1997 |chapter=Chapter 4: Mothers, Labels, and Misogyny |title=Women in Human Evolution |editor=Hager LD |publisher=Routledge |location=London |pages=75–89 |isbn=9780415108331}}</ref> But the concept of Eve caught on with the public and was repeated in a ''[[Newsweek]]'' cover story (11 January 1988 issue featured a depiction of Adam and Eve on the cover, with the title "The Search for Adam and Eve"),<ref>{{cite web| vauthors = Tierney J |year=1992 |title=The Search for Adam and Eve|url= http://www.virginia.edu/woodson/courses/aas102%20(spring%2001)/articles/tierney.html |work= Newsweek |publisher= Carter G. Woodson Institute for Afro-American and African Studies |via=Internet Archive |archive-url=https://web.archive.org/web/20150320110036/http://www.virginia.edu/woodson/courses/aas102%20(spring%2001)/articles/tierney.html |access-date=21 July 2019|archive-date=20 March 2015 }}</ref> and a cover story in ''[[Time (magazine)|Time]]'' on 26 January 1987.<ref>{{cite magazine| vauthors = Lemonick MD |date=26 January 1987|title= Everyone's Genealogical Mother|url= http://www.time.com/time/magazine/article/0,9171,963320,00.html |archive-url= https://web.archive.org/web/20080923010301/http://www.time.com/time/magazine/article/0,9171,963320,00.html |url-status= dead |archive-date= 23 September 2008 |magazine=Time |access-date=13 May 2013}}</ref>

===Criticism and later research===
Shortly after the 1987 publication, criticism of its methodology and secondary conclusions was published.<ref>{{cite journal | vauthors = Darlu P, Tassy P | title = Disputed African origin of human populations | journal = Nature | volume = 329 | issue = 6135 | pages = 111–112 | year = 1987 | pmid = 3114640 | doi = 10.1038/329111b0 | s2cid = 4313392 | bibcode = 1987Natur.329..111D | doi-access = free }}</ref> Both the dating of mt-Eve and the relevance of the age of the purely matrilineal descent for population replacement were subjects of controversy during the 1990s;<ref>{{cite journal | vauthors = Maddison DR |title=African Origin of human mitochondrial DNA reexamined |journal=Systematic Zoology |volume=40 |issue=3 |pages=355–63 |year=1991 |doi=10.2307/2992327 |jstor=2992327 }}</ref><ref>{{cite journal | vauthors = Nei M | title = Age of the common ancestor of human mitochondrial DNA | journal = Molecular Biology and Evolution | volume = 9 | issue = 6 | pages = 1176–1178 | date = November 1992 | pmid = 1435241 | doi = 10.1093/oxfordjournals.molbev.a040785 | doi-access = free }}</ref><ref>{{cite journal | vauthors = Ayala FJ | title = The myth of Eve: molecular biology and human origins | journal = Science | volume = 270 | issue = 5244 | pages = 1930–1936 | date = December 1995 | pmid = 8533083 | doi = 10.1126/science.270.5244.1930 | s2cid = 42801341 | doi-access = free | bibcode = 1995Sci...270.1930A }}</ref><ref>{{cite journal | vauthors = Templeton A | title = Out of Africa again and again | journal = Nature | volume = 416 | issue = 6876 | pages = 45–51 | date = March 2002 | pmid = 11882887 | doi = 10.1038/416045a | s2cid = 4397398 | bibcode = 2002Natur.416...45T }}</ref> [[Alan Templeton]] (1997) asserted that the study did "not support the hypothesis of a recent African origin for all of humanity following a split between Africans and non-Africans 100,000 years ago" and also did "not support the hypothesis of a recent global replacement of humans coming out of Africa."<ref>{{cite journal | vauthors = Templeton AR | title = Out of Africa? What do genes tell us? | journal = Current Opinion in Genetics & Development | volume = 7 | issue = 6 | pages = 841–847 | date = December 1997 | pmid = 9468796 | doi = 10.1016/S0959-437X(97)80049-4 }}</ref>

The placement by {{Harvtxt|Cann|Stoneking|Wilson|1987}} of a relatively small population of humans in sub-Saharan Africa was consistent with the hypothesis of Cann (1982) and lent considerable support for the "recent out-of-Africa" scenario.

In 1999, Krings et al. eliminated problems in molecular clocking postulated by Nei (1992)<ref>{{cite journal | vauthors = Nei M |year=1992 |title=Age of the common ancestor of human mitochondrial DNA |url=https://www.researchgate.net/publication/21720959 |journal=Molecular Biology and Evolution |volume=9 |issue=6 |pages=1176–1178|doi=10.1093/oxfordjournals.molbev.a040785 |pmid=1435241 |doi-access=free }}</ref> when it was found that the mtDNA sequence for the same region was substantially different from the MRCA relative to any human sequence.<ref>{{cite journal | vauthors = Krings M, Salem AE, Bauer K, Geisert H, Malek AK, Chaix L, Simon C, Welsby D, Di Rienzo A, Utermann G, Sajantila A, Pääbo S, Stoneking M | display-authors = 6 | title = mtDNA analysis of Nile River Valley populations: A genetic corridor or a barrier to migration? | language = English | journal = American Journal of Human Genetics | volume = 64 | issue = 4 | pages = 1166–1176 | date = April 1999 | pmid = 10090902 | pmc = 1377841 | doi = 10.1086/302314 }}</ref><ref>{{cite journal | vauthors = Krings M, Stone A, Schmitz RW, Krainitzki H, Stoneking M, Pääbo S | title = Neandertal DNA sequences and the origin of modern humans | language = English | journal = Cell | volume = 90 | issue = 1 | pages = 19–30 | date = July 1997 | pmid = 9230299 | doi = 10.1016/S0092-8674(00)80310-4 | s2cid = 13581775 | doi-access = free | hdl = 11858/00-001M-0000-0025-0960-8 | hdl-access = free }}</ref>

In 1997, {{Harvtxt|Parsons|Muniec|Sullivan|Alliston-Greiner|1997}} published a study of mtDNA mutation rates in a single, well-documented family (the [[Romanov]] family of Russian royalty). In this study, they calculated a mutation rate upwards of twenty times higher than previous results.<ref>{{cite journal | vauthors = Parsons TJ, Muniec DS, Sullivan K, Woodyatt N, Alliston-Greiner R, Wilson MR, Berry DL, Holland KA, Weedn VW, Gill P, Holland MM | display-authors = 6 | title = A high observed substitution rate in the human mitochondrial DNA control region | journal = Nature Genetics | volume = 15 | issue = 4 | pages = 363–368 | date = April 1997 | pmid = 9090380 | doi = 10.1038/ng0497-363 | s2cid = 32812244 }}</ref>

Although the original research did have analytical limitations, the estimate on the age of the mt-MRCA has proven robust.<ref>{{cite web| vauthors = Holsinger K|url= http://darwin.eeb.uconn.edu/eeb348/lecturenotes/coalescent/node5.html |title=(Mathematics of the coalescent) An example: Mitochondrial Eve |work=Holsinger Lab |date=29 September 2012 |access-date=16 May 2013}}</ref><ref>{{cite journal | vauthors = Cyran KA, Kimmel M | title = Alternatives to the Wright-Fisher model: the robustness of mitochondrial Eve dating | journal = Theoretical Population Biology | volume = 78 | issue = 3 | pages = 165–172 | date = November 2010 | pmid = 20600209 | doi = 10.1016/j.tpb.2010.06.001 }}</ref> More recent age estimates have remained consistent with the 140–200 [[Year#Abbreviations yr and ya|kya]] estimate published in 1987: A 2013 estimate dated Mitochondrial Eve to about 160 kya (within the reserved estimate of the original research) and [[Out of Africa II]] to about 95 kya.<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 | display-authors = 6 | title = A revised timescale for human evolution based on ancient mitochondrial genomes | journal = Current Biology | volume = 23 | issue = 7 | pages = 553–559 | date = April 2013 | pmid = 23523248 | pmc = 5036973 | doi = 10.1016/j.cub.2013.02.044 }}</ref> Another 2013 study (based on [[genome sequencing]] of 69 people from 9 different populations) reported the age of Mitochondrial Eve between 99 and 148 kya and that of the [[Y-MRCA]] between 120 and 156 kya.<ref name=poz/>

==Female and mitochondrial ancestry==
{{main|Macro-haplogroup L (mtDNA)}}
{{further|Genetic genealogy (matrilineal)|Mitochondrial DNA|Human mitochondrial molecular clock}}
[[File:MtDNA-MRCA-generations-Evolution.svg|thumb|left|200px|Through [[Genetic drift|random drift]] or selection the female lineage will trace back to a single female, such as Mitochondrial Eve. In this example over five generations colors represent extinct matrilineal lines and black the matrilineal line descended from mtDNA MRCA.]]

Without a DNA sample, it is not possible to reconstruct the complete genetic makeup ([[genome]]) of any individual who died very long ago. By analysing descendants' DNA, however, parts of ancestral genomes are estimated by scientists. Mitochondrial DNA (mtDNA, the DNA located in [[mitochondrion|mitochondria]], different from the [[Nuclear DNA|DNA in the nucleus]] of a cell) and Y-chromosome DNA are commonly used to trace ancestry in this manner. mtDNA is generally passed un-mixed from mothers to children of both sexes, along the maternal line, or [[matrilineally]].<ref>{{cite journal | vauthors = Giles RE, Blanc H, Cann HM, Wallace DC | title = Maternal inheritance of human mitochondrial DNA | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 77 | issue = 11 | pages = 6715–6719 | date = November 1980 | pmid = 6256757 | pmc = 350359 | doi = 10.1073/pnas.77.11.6715 | doi-access = free | bibcode = 1980PNAS...77.6715G }}</ref><ref>{{cite journal | vauthors = Birky CW | title = Uniparental inheritance of organelle genes | journal = Current Biology | volume = 18 | issue = 16 | pages = R692–R695 | date = August 2008 | pmid = 18727899 | doi = 10.1016/j.cub.2008.06.049 | s2cid = 9866662 | doi-access = free }}</ref> Matrilineal descent goes back through mothers, to their mothers, until all female lineages converge.

Branches are identified by one or more unique markers which give a mitochondrial "DNA signature" or "[[haplotype]]" (e.g. the [[Cambridge Reference Sequence|CRS]] is a haplotype). Each marker is a DNA base-pair that has resulted from an [[single-nucleotide polymorphism|SNP]] [[mutation]]. Scientists sort mitochondrial DNA results into more or less related groups, with more or less recent common ancestors. This leads to the construction of a DNA [[family tree]] where the branches are in biological terms [[clade]]s, and the common ancestors such as Mitochondrial Eve sit at branching points in this tree. Major branches are said to define a [[haplogroup]] (e.g. CRS belongs to [[Haplogroup H (mtDNA)|haplogroup H]]), and large branches containing several haplogroups are called "macro-haplogroups".

[[File:Mitochondrial eve tree.gif|thumb|right|200px|Simplified human mitochondrial phylogeny]]

The mitochondrial clade which Mitochondrial Eve defines is the [[species]] ''[[species:Homo sapiens|Homo sapiens sapiens]]'' itself, or at least the current population or "[[chronospecies]]" as it exists today. In principle, earlier Eves can also be defined going beyond the species, for example one who is ancestral to both modern humanity and [[Neanderthal]]s, or, further back, an "Eve" ancestral to all members of [[genus]] ''[[species:Homo|Homo]]'' and chimpanzees in genus ''[[species:Pan|Pan]]''. According to current nomenclature, Mitochondrial Eve's haplogroup was within [[Macro-haplogroup L (mtDNA)|mitochondrial haplogroup L]] because this macro-haplogroup contains all surviving human mitochondrial lineages today, and she must predate the emergence of [[Haplogroup L0|L0]].

The variation of mitochondrial DNA between different people can be used to estimate the time back to a common ancestor, such as Mitochondrial Eve. This works because, along any particular line of descent, mitochondrial DNA accumulates mutations at the rate of approximately one every 3,500 years per nucleotide.<ref name="Soares09">{{cite journal | vauthors = Soares P, Ermini L, Thomson N, Mormina M, Rito T, Röhl A, Salas A, Oppenheimer S, Macaulay V, Richards MB | display-authors = 6 | title = Correcting for purifying selection: an improved human mitochondrial molecular clock | journal = American Journal of Human Genetics | volume = 84 | issue = 6 | pages = 740–759 | date = June 2009 | pmid = 19500773 | pmc = 2694979 | doi = 10.1016/j.ajhg.2009.05.001 }}</ref><ref>{{cite journal | vauthors = Gibbons A | title = Calibrating the mitochondrial clock | journal = Science | volume = 279 | issue = 5347 | pages = 28–29 | date = January 1998 | pmid = 9441404 | doi = 10.1126/science.279.5347.28 | s2cid = 29855766 | bibcode = 1998Sci...279...28G }}</ref>{{efn|group=note|There are sites in mtDNA (such as: 16129, 16223, 16311, 16362) that evolve more rapidly, have been noted to change within intragenerational timeframes – {{Harvtxt |Excoffier|Yang|1999}}.}} A certain number of these new variants will survive into modern times and be identifiable as distinct lineages. At the same time some branches, including even very old ones, come to an end when the last family in a distinct branch has no daughters.

Mitochondrial Eve is the most recent common matrilineal ancestor for all modern humans. Whenever one of the two most ancient branch lines dies out (by producing only non-matrilinear descendants at that time), the MRCA will move to a more recent female ancestor, always the most recent mother to have more than one daughter with living maternal line descendants alive today. The number of mutations that can be found distinguishing modern people is determined by two criteria: first and most obviously, the time back to her, but second and less obviously by the varying rates at which new branches have come into existence and old branches have become extinct. By looking at the number of mutations which have been accumulated in different branches of this family tree, and looking at which geographical regions have the widest range of least related branches, the region where Eve lived can be proposed.

==Popular reception and misconceptions==
''Newsweek'' reported on Mitochondrial Eve based on the Cann ''et al.'' study in January 1988, under a heading of "Scientists Explore a Controversial Theory About Man's Origins". The edition sold a record number of copies.<ref name="Oppenheimer2003" />

The popular name "mitochondrial Eve", of 1980s coinage,<ref name=lew/> has contributed to a number of popular misconceptions. At first, the announcement of a "mitochondrial Eve" was even greeted with endorsement from [[young earth creationism|young earth creationists]], who viewed the theory as a validation of the [[genesis creation story|biblical creation story]].<ref>{{cite journal| vauthors = Wieland C |url= http://creation.com/mitochondrial-eve-and-biblical-eve-are-looking-good-criticism-of-young-age-is-premature|title=Mitochondrial Eve and biblical Eve are looking good: criticism of young age is premature| journal= Journal of Creation |volume= 19|issue=1 |pages= 57–59| year=2005}}</ref><ref>{{cite web| vauthors = Nelson CW |url= http://www.answersingenesis.org/articles/tj/v17/n1/events |title= Genetics and Biblical Demographic Events |work= [[Answers in Genesis]]|date=1 April 2003 |access-date=16 May 2013}}</ref><ref>{{cite web| vauthors = Oakes J|url= http://www.evidenceforchristianity.org/can-the-human-arguments-about-mitochondrial-eve-and-y-chromosome-adam-be-extended-to-the-animal-world-to-test-the-reality-of-the-flood-of-noahr/ |title= Can the human arguments about mitochondrial Eve and y-chromosome Adam be extended to the animal world to test the reality of the flood of Noah?|work=Evidence for Christianity |date= 25 January 2007 |publisher=Answers in Genesis| access-date=16 May 2013}}</ref>{{npsn|date=February 2020}}

Due to such misunderstandings, authors of [[popular science]] publications since the 1990s have been emphatic in pointing out that the name is merely a popular convention, and that the mt-MRCA was not in any way the "first woman".<ref name="Dawkins04">{{cite book | vauthors = Dawkins R |title=The ancestor's tale: a pilgrimage to the dawn of evolution |publisher=Houghton Mifflin |location=Boston |year=2004 |isbn=978-0-618-00583-3 |title-link=The Ancestor's Tale }}</ref> Her position is purely the result of genealogical history of human populations later, and as matrilineal lineages die out, the position of mt-MRCA keeps moving forward to younger individuals over time.

In ''[[River Out of Eden]]'' (1995), [[Richard Dawkins]] discussed human ancestry in the context of a "river of genes", including an explanation of the concept of Mitochondrial Eve.<ref name="Dawkins1995">{{cite book | vauthors = Dawkins R |title=River out of eden: a Darwinian view of life|url= https://books.google.com/books?id=DxmKvnPyBSoC&pg=PP1|access-date=5 December 2011|year=1995|publisher=Basic Books|isbn=978-0-465-06990-3}}</ref> ''[[The Seven Daughters of Eve]]'' (2002) presented the topic of human mitochondrial genetics to a general audience.<ref name="Sykes2002">{{cite book | vauthors = Sykes B |title=The Seven Daughters of Eve: The Science That Reveals Our Genetic Ancestry|year=2002|publisher=W. W. Norton & Company|isbn=978-0-393-32314-6|url-access=registration|url= https://archive.org/details/sevendaughtersof00brya}}</ref> [[The Real Eve|''The Real Eve: Modern Man's Journey Out of Africa'']] by [[Stephen Oppenheimer]] (2003)<ref name="Oppenheimer2003">{{cite book | vauthors = Oppenheimer S |title=The Real Eve: Modern Man's Journey Out of Africa |year=2003 |location=New York |publisher=Basic Books |isbn=978-0-7867-1192-5 |url= https://books.google.com/books?id=5tP5Wb92wT4C }}</ref> was adapted into a 2002 [[Discovery Channel]] documentary.<ref>{{Cite book|last=Oppenheimer|first=Stephen|url=https://books.google.com/books?id=5tP5Wb92wT4C&q=The+Real+Eve:+Modern+Man's+Journey+Out+of+Africa+2003|title=The Real Eve: Modern Man's Journey Out of Africa|date=2003|publisher=Carroll & Graf|isbn=978-0-7867-1192-5|language=en}}</ref>

===Not the only woman===
One common misconception surrounding Mitochondrial Eve is that since all women alive today descended in a [[matrilineal|direct unbroken female line]] from her, she must have been the only woman alive at the time.<ref name="Dawkins04"/> However, [[nuclear DNA]] studies indicate that the [[effective population size]] of ancient humans never dropped below tens of thousands.<ref name="Takahata93">{{cite journal | vauthors = Takahata N | title = Allelic genealogy and human evolution | journal = Molecular Biology and Evolution | volume = 10 | issue = 1 | pages = 2–22 | date = January 1993 | pmid = 8450756 | doi = 10.1093/oxfordjournals.molbev.a039995 | doi-access = free }}</ref> Other women living during Eve's time may have descendants alive today but not in a direct female line.<ref>{{Cite web |date=14 January 2008 |title=Are we all descended from a common female ancestor? |url=https://science.howstuffworks.com/life/evolution/female-ancestor.htm |access-date=17 May 2022 |website=HowStuffWorks |language=en}}</ref>

===Not a fixed individual over time===
[[File:MtDNA-MRCA-generations-Evolution-new Eve.svg|thumb|After the lineage in black fails to follow on, the new Mitochondrial Eve will go to the next woman who had, at least, two daughters.]]
The definition of Mitochondrial Eve is fixed, but the woman in prehistory who fits this definition can change. That is, not only can our knowledge of when and where Mitochondrial Eve lived change due to new discoveries, but the actual Mitochondrial Eve can change. The Mitochondrial Eve can change, when a mother-daughter line comes to an end. It follows from the definition of Mitochondrial Eve that she had at least two daughters who both have unbroken ''female'' lineages that have survived to the present day. In every generation mitochondrial lineages end&nbsp;– when a woman with unique mtDNA dies with no daughters. When the mitochondrial lineages of daughters of Mitochondrial Eve die out, then the title of "Mitochondrial Eve" shifts forward from the remaining daughter through her matrilineal descendants, until the first descendant is reached who had two or more daughters who together have all living humans as their matrilineal descendants. Once a lineage has died out it is irretrievably lost and this mechanism can thus only shift the title of "Mitochondrial Eve" forward in time.<ref>{{cite magazine| vauthors = Learn JP |title=No, a Mitochondrial 'Eve' Is Not the First Female in a Species|url=https://www.smithsonianmag.com/science-nature/no-mitochondrial-eve-not-first-female-species-180959593/|access-date=23 February 2021|magazine=Smithsonian Magazine|language=en}}</ref>

Because mtDNA mapping of humans is very incomplete, the discovery of living mtDNA lines which predate our current concept of "Mitochondrial Eve" could result in the title moving to an earlier woman. This happened to her male counterpart, "Y-chromosomal Adam", when an older Y line, [[Haplogroup A (Y-DNA)#A00 (A00 AF6)|haplogroup A-00]], was discovered.<ref>{{cite journal | vauthors = Mendez FL, Krahn T, Schrack B, Krahn AM, Veeramah KR, Woerner AE, Fomine FL, Bradman N, Thomas MG, Karafet TM, Hammer MF | display-authors = 6 | title = An African American paternal lineage adds an extremely ancient root to the human Y chromosome phylogenetic tree | journal = American Journal of Human Genetics | volume = 92 | issue = 3 | pages = 454–459 | date = March 2013 | pmid = 23453668 | pmc = 3591855 | doi = 10.1016/j.ajhg.2013.02.002 }}</ref>

===Not necessarily a contemporary of "Y-chromosomal Adam"===
Sometimes Mitochondrial Eve is assumed to have lived at the same time as [[Y-chromosomal Adam]] (from whom all living males are descended patrilineally), and perhaps even met and mated with him. Even if this were true, which is currently regarded as highly unlikely, this would only be a coincidence. Like Mitochondrial "Eve", Y-chromosomal "Adam" probably lived in Africa. A recent study (March 2013) concluded however that "Eve" lived much later than "Adam"&nbsp;– some 140,000 years later.<ref name="adam2013">{{cite magazine |url= https://www.newscientist.com/article/dn23240-the-father-of-all-men-is-340000-years-old/ |title=The father of all men is 340,000 years old |magazine=New Scientist |date=6 March 2013 |access-date=13 March 2013 | vauthors = Barras C }}</ref> (Earlier studies considered, conversely, that "Eve" lived earlier than "Adam".)<ref>{{cite journal | vauthors = Cruciani F, Trombetta B, Massaia A, Destro-Bisol G, Sellitto D, Scozzari R | title = A revised root for the human Y chromosomal phylogenetic tree: the origin of patrilineal diversity in Africa | journal = American Journal of Human Genetics | volume = 88 | issue = 6 | pages = 814–818 | date = June 2011 | pmid = 21601174 | pmc = 3113241 | doi = 10.1016/j.ajhg.2011.05.002 }}</ref> More recent studies indicate that it is not impossible that Mitochondrial Eve and Y-chromosomal Adam might have lived around the same time.<ref>{{cite journal|url= http://www.nature.com/news/genetic-adam-and-eve-did-not-live-too-far-apart-in-time-1.13478 |title=Genetic Adam and Eve did not live too far apart in time | vauthors = Callaway E |date=6 August 2013 |journal=Nature |doi=10.1038/nature.2013.13478|s2cid=170608686 }}</ref>

===Not the most recent ancestor shared by all humans===
{{Main|Most recent common ancestor}}
Mitochondrial Eve is the most recent common ''matrilineal'' ancestor, not the ''most recent common ancestor''. Since the mtDNA is inherited maternally and recombination is either rare or absent, it is relatively easy to track the ancestry of the lineages back to a MRCA; however, this MRCA is valid only when discussing mitochondrial DNA. An approximate sequence from newest to oldest can list various important points in the ancestry of modern human populations:

* [[most recent common ancestor|The human MRCA]]. The time period that human MRCA lived is unknown. Rohde et al put forth a "rough guess" that the MRCA could have existed 5000 years ago; however, the authors state that this estimate is "extremely tentative, and the model contains several obvious sources of error, as it was motivated more by considerations of theoretical insight and tractability than by realism."<ref name=Rodhe2004>{{cite journal | vauthors = Rohde DL, Olson S, Chang JT | title = Modelling the recent common ancestry of all living humans | journal = Nature | volume = 431 | issue = 7008 | pages = 562–566 | date = September 2004 | pmid = 15457259 | doi = 10.1038/nature02842 | s2cid = 3563900 | citeseerx = 10.1.1.78.8467 | bibcode = 2004Natur.431..562R }}</ref> Just a few thousand years before the most recent single ancestor shared by all living humans was the time at which all humans who were then alive either left no descendants alive today or were common ancestors of all humans alive today. However, such a late date is difficult to reconcile with the geographical spread of our species and the consequent isolation of different groups from each other. For example, it is generally accepted that the indigenous population of Tasmania was isolated from all other humans between the rise in sea level after the last ice age some 8000 years ago and the arrival of Europeans. Estimates of the MRCA of even closely related human populations have been much more than 5000 years ago.<ref>{{Cite journal |last1=Zhou |first1=Jin |last2=Teo |first2=Yik-Ying |date=August 2016 |title=Estimating time to the most recent common ancestor (TMRCA): comparison and application of eight methods |journal=European Journal of Human Genetics |language=en |volume=24 |issue=8 |pages=1195–1201 |doi=10.1038/ejhg.2015.258 |pmid=26669663 |pmc=4970674 |s2cid=965600 |issn=1476-5438|doi-access=free }}</ref>
* The [[identical ancestors point]]. In other words, "each present-day human has exactly the same set of genealogical ancestors" alive at the "identical ancestors point" in time. This is far more recent than when Mitochondrial Eve was proposed to have lived.<ref name=Rodhe2004/>
* Mitochondrial Eve, the most recent female-line common ancestor of all living people.
* "Y-chromosomal Adam", the most recent male-line common ancestor of all living people.

== See also ==
{{div col|colwidth=22em}}
* [[Archaeogenetics]]
* [[Coalescent theory]]
* [[Eurasian Adam]]
* [[Genealogical DNA test]]
* [[Genetic genealogy]]
* [[Haplogroup L0]]
* [[Human evolution]]
* [[Human mitochondrial DNA haplogroups]]
* [[Last universal ancestor]]
* [[Macro-haplogroup L (mtDNA)]]
* [[Mitochondrial genome]]
* [[Monogenism]]
* [[Neutral theory of molecular evolution]]
* [[Prehistoric demography]]
* [[Single origin hypothesis]]
* [[Timeline of evolution]]
* [[Timeline of human evolution]]
* [[Y-chromosomal Aaron]]
* [[Y-chromosomal Adam]]
* [[Women in prehistory]]
{{div col end}}
{{MtDNA}}

==Notes==
{{reflist|group=note}}

== References ==
{{reflist|30em}}

== Further reading ==
<!------{{cite journal |title= }} Please copy this first and the past names, ---->
{{refbegin|colwidth=30em}}
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* {{cite journal | vauthors = Nei M | title = Age of the common ancestor of human mitochondrial DNA | journal = Molecular Biology and Evolution | volume = 9 | issue = 6 | pages = 1176–1178 | date = November 1992 | pmid = 1435241 | doi = 10.1093/oxfordjournals.molbev.a040785 | doi-access = free }}
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* {{cite book | vauthors = Oppenheimer S |title=The Real Eve: Modern Man's Journey Out of Africa |publisher=Carroll & Graf |location=New York |year=2004 |isbn=978-0-7867-1334-9 }}
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* {{cite journal | vauthors = Takahata N | title = Allelic genealogy and human evolution | journal = Molecular Biology and Evolution | volume = 10 | issue = 1 | pages = 2–22 | date = January 1993 | pmid = 8450756 | doi = 10.1093/oxfordjournals.molbev.a039995 | doi-access = free }}
* {{cite journal | vauthors = Takahata N, Lee SH, Satta Y | title = Testing multiregionality of modern human origins | journal = Molecular Biology and Evolution | volume = 18 | issue = 2 | pages = 172–183 | date = February 2001 | pmid = 11158376 | doi = 10.1093/oxfordjournals.molbev.a003791 | doi-access = free }}
* {{cite journal | vauthors = Tamura K, Nei M | title = Estimation of the number of nucleotide substitutions in the control region of mitochondrial DNA in humans and chimpanzees | journal = Molecular Biology and Evolution | volume = 10 | issue = 3 | pages = 512–526 | date = May 1993 | pmid = 8336541 | doi = 10.1093/oxfordjournals.molbev.a040023 | doi-access = free }}
* {{cite journal | vauthors = Tang H, Siegmund DO, Shen P, Oefner PJ, Feldman MW | title = Frequentist estimation of coalescence times from nucleotide sequence data using a tree-based partition | journal = Genetics | volume = 161 | issue = 1 | pages = 447–459 | date = May 2002 | pmid = 12019257 | pmc = 1462078 | doi = 10.1093/genetics/161.1.447 }}
* {{cite journal | vauthors = Tishkoff SA, Gonder MK, Henn BM, Mortensen H, Knight A, Gignoux C, Fernandopulle N, Lema G, Nyambo TB, Ramakrishnan U, Reed FA, Mountain JL | display-authors = 6 | title = History of click-speaking populations of Africa inferred from mtDNA and Y chromosome genetic variation | journal = Molecular Biology and Evolution | volume = 24 | issue = 10 | pages = 2180–2195 | date = October 2007 | pmid = 17656633 | doi = 10.1093/molbev/msm155 | doi-access = free }}
* {{cite journal | vauthors = Tishkoff SA, Reed FA, Friedlaender FR, Ehret C, Ranciaro A, Froment A, Hirbo JB, Awomoyi AA, Bodo JM, Doumbo O, Ibrahim M, Juma AT, Kotze MJ, Lema G, Moore JH, Mortensen H, Nyambo TB, Omar SA, Powell K, Pretorius GS, Smith MW, Thera MA, Wambebe C, Weber JL, Williams SM | display-authors = 6 | title = The genetic structure and history of Africans and African Americans | journal = Science | volume = 324 | issue = 5930 | pages = 1035–1044 | date = May 2009 | pmid = 19407144 | pmc = 2947357 | doi = 10.1126/science.1172257 | bibcode = 2009Sci...324.1035T }}
* {{cite journal | vauthors = Vigilant L, Pennington R, Harpending H, Kocher TD, Wilson AC | title = Mitochondrial DNA sequences in single hairs from a southern African population | journal = Proceedings of the National Academy of Sciences of the United States of America | volume = 86 | issue = 23 | pages = 9350–9354 | date = December 1989 | pmid = 2594772 | pmc = 298493 | doi = 10.1073/pnas.86.23.9350 | doi-access = free | bibcode = 1989PNAS...86.9350V }}
* {{cite journal | vauthors = Vigilant L, Stoneking M, Harpending H, Hawkes K, Wilson AC | title = African populations and the evolution of human mitochondrial DNA | journal = Science | volume = 253 | issue = 5027 | pages = 1503–1507 | date = September 1991 | pmid = 1840702 | doi = 10.1126/science.1840702 | bibcode = 1991Sci...253.1503V }}
* {{cite journal | vauthors = Watson E, Forster P, Richards M, Bandelt HJ | title = Mitochondrial footprints of human expansions in Africa | journal = American Journal of Human Genetics | volume = 61 | issue = 3 | pages = 691–704 | date = September 1997 | pmid = 9326335 | pmc = 1715955 | doi = 10.1086/515503 }}
* {{cite journal | vauthors = White TD, Asfaw B, Beyene Y, Haile-Selassie Y, Lovejoy CO, Suwa G, WoldeGabriel G | title = Ardipithecus ramidus and the paleobiology of early hominids | journal = Science | volume = 326 | issue = 5949 | pages = 75–86 | date = October 2009 | pmid = 19810190 | doi = 10.1126/science.1175802 | s2cid = 20189444 | bibcode = 2009Sci...326...75W }}
* {{cite journal | vauthors = Wilder JA, Mobasher Z, Hammer MF | title = Genetic evidence for unequal effective population sizes of human females and males | journal = Molecular Biology and Evolution | volume = 21 | issue = 11 | pages = 2047–2057 | date = November 2004 | pmid = 15317874 | doi = 10.1093/molbev/msh214 | doi-access = free }}
* {{cite journal | vauthors = Wilson AC, Cann RL, Carr SM, George M, Gyllensten UB, Helm-Bychowski KM, Higuchi RG, Palumbi SR, Prager EM, Sage RD, Stoneking M | display-authors = 6 |title=Mitochondrial DNA and two perspectives on evolutionary genetics |journal=Biological Journal of the Linnean Society |volume=26 |issue=4 |pages=375–400 |year=1985 |doi=10.1111/j.1095-8312.1985.tb02048.x}}
{{refend}}

== External links ==
{{Spoken Wikipedia|Mitochondrial Eve.ogg|date=22 April 2005|SubCat=}}
{{Commons category|Mitochondrial Eve}}
* [http://www.talkorigins.org/faqs/homs/mitoeve.html Krishna Kunchithapadam, "What, if anything, is a Mitochondrial Eve?"] a simple explanation
* [https://www.youtube.com/watch?v=9wS1za00mMM&feature=&p=A0D41D79D1CE0DBB&index=0&playnext=1 ''The Real Eve: Modern Man's Journey Out of Africa''] – by [[Stephen Oppenheimer]] – [[Discovery Channel]], 2002

{{Human Evolution}}
{{Adam and Eve}}
{{portal bar |Evolutionary biology|Paleontology}}

[[Category:Human mtDNA haplogroups| ]]
[[Category:Human mitochondrial genetics]]
[[Category:Genetic genealogy]]
[[Category:Recent African origin of modern humans]]
[[Category:Female]]
[[Category:Hebrew Bible in popular culture]]
[[Category:Women in Africa]]
[[Category:Women's history]]
[[Category:Events in biological evolution]]

Latest revision as of 21:41, 6 December 2024

Haplogroup L
Possible time of originc. 100–230 kya[note 1][note 2]
Possible place of originEast Africa
Ancestorn/a
DescendantsMitochondrial macro-haplogroups L0, L1, and L5
Defining mutationsNone

In human genetics, the Mitochondrial Eve (more technically known as the Mitochondrial-Most Recent Common Ancestor, shortened to mt-Eve or mt-MRCA) is the matrilineal most recent common ancestor (MRCA) of all living humans. In other words, she is defined as the most recent woman from whom all living humans descend in an unbroken line purely through their mothers and through the mothers of those mothers, back until all lines converge on one woman.

In terms of mitochondrial haplogroups, the mt-MRCA is situated at the divergence of macro-haplogroup L into L0 and L1–6. As of 2013, estimates on the age of this split ranged at around 155,000 years ago,[note 3] consistent with a date later than the speciation of Homo sapiens but earlier than the recent out-of-Africa dispersal.[4][1][5]

The male analog to the "Mitochondrial Eve" is the "Y-chromosomal Adam" (or Y-MRCA), the individual from whom all living humans are patrilineally descended. As the identity of both matrilineal and patrilineal MRCAs is dependent on genealogical history (pedigree collapse), they need not have lived at the same time. As of 2015, estimates of the age of the Y-MRCA range around 200,000 to 300,000 years ago, roughly consistent with the emergence of anatomically modern humans.[6]

The name "Mitochondrial Eve" alludes to the biblical Eve, which has led to repeated misrepresentations or misconceptions in journalistic accounts on the topic. Popular science presentations of the topic usually point out such possible misconceptions by emphasizing the fact that the position of mt-MRCA is neither fixed in time (as the position of mt-MRCA moves forward in time as mitochondrial DNA (mtDNA) lineages become extinct), nor does it refer to a "first woman", nor the only living female of her time, nor the first member of a "new species".[note 4]

History

[edit]

Early research

[edit]

Early research using molecular clock methods was done during the late 1970s to early 1980s. Allan Wilson, Mark Stoneking, Rebecca L. Cann and Wesley Brown found that mutation in human mtDNA was unexpectedly fast, at 0.02 substitution per base (1%) in a million years, which is 5–10 times faster than in nuclear DNA.[8] Related work allowed for an analysis of the evolutionary relationships among gorillas, chimpanzees (common chimpanzee and bonobo) and humans.[9] With data from 21 human individuals, Brown published the first estimate on the age of the mt-MRCA at 180,000 years ago in 1980.[10] A statistical analysis published in 1982 was taken as evidence for recent African origin (a hypothesis which at the time was competing with Asian origin of H. sapiens).[11][12][13]

1987 publication

[edit]

By 1985, data from the mtDNA of 145 women of different populations, and of two cell lines, HeLa and GM 3043, derived from an African American and a ǃKung respectively, were available. After more than 40 revisions of the draft, the manuscript was submitted to Nature in late 1985 or early 1986[13] and published on 1 January 1987. The published conclusion was that all current human mtDNA originated from a single population from Africa, at the time dated to between 140,000 and 200,000 years ago.[14]

The dating for "Eve" was a blow to the multiregional hypothesis, which was debated at the time, and a boost to the theory of the recent origin model.[15]

Cann, Stoneking and Wilson did not use the term "Mitochondrial Eve" or even the name "Eve" in their original paper. It is however used by Cann in an article entitled "In Search of Eve" in the September–October 1987 issue of The Sciences.[16] It also appears in the October 1987 article in Science by Roger Lewin, headlined "The Unmasking of Mitochondrial Eve".[17] The biblical connotation was very clear from the start. The accompanying research news in Nature had the title "Out of the garden of Eden".[18]

Wilson himself preferred the term "Lucky Mother"[19] and thought the use of the name Eve "regrettable".[17][20] But the concept of Eve caught on with the public and was repeated in a Newsweek cover story (11 January 1988 issue featured a depiction of Adam and Eve on the cover, with the title "The Search for Adam and Eve"),[21] and a cover story in Time on 26 January 1987.[22]

Criticism and later research

[edit]

Shortly after the 1987 publication, criticism of its methodology and secondary conclusions was published.[23] Both the dating of mt-Eve and the relevance of the age of the purely matrilineal descent for population replacement were subjects of controversy during the 1990s;[24][25][26][27] Alan Templeton (1997) asserted that the study did "not support the hypothesis of a recent African origin for all of humanity following a split between Africans and non-Africans 100,000 years ago" and also did "not support the hypothesis of a recent global replacement of humans coming out of Africa."[28]

The placement by Cann, Stoneking & Wilson (1987) of a relatively small population of humans in sub-Saharan Africa was consistent with the hypothesis of Cann (1982) and lent considerable support for the "recent out-of-Africa" scenario.

In 1999, Krings et al. eliminated problems in molecular clocking postulated by Nei (1992)[29] when it was found that the mtDNA sequence for the same region was substantially different from the MRCA relative to any human sequence.[30][31]

In 1997, Parsons et al. (1997) published a study of mtDNA mutation rates in a single, well-documented family (the Romanov family of Russian royalty). In this study, they calculated a mutation rate upwards of twenty times higher than previous results.[32]

Although the original research did have analytical limitations, the estimate on the age of the mt-MRCA has proven robust.[33][34] More recent age estimates have remained consistent with the 140–200 kya estimate published in 1987: A 2013 estimate dated Mitochondrial Eve to about 160 kya (within the reserved estimate of the original research) and Out of Africa II to about 95 kya.[3] Another 2013 study (based on genome sequencing of 69 people from 9 different populations) reported the age of Mitochondrial Eve between 99 and 148 kya and that of the Y-MRCA between 120 and 156 kya.[2]

Female and mitochondrial ancestry

[edit]
Through random drift or selection the female lineage will trace back to a single female, such as Mitochondrial Eve. In this example over five generations colors represent extinct matrilineal lines and black the matrilineal line descended from mtDNA MRCA.

Without a DNA sample, it is not possible to reconstruct the complete genetic makeup (genome) of any individual who died very long ago. By analysing descendants' DNA, however, parts of ancestral genomes are estimated by scientists. Mitochondrial DNA (mtDNA, the DNA located in mitochondria, different from the DNA in the nucleus of a cell) and Y-chromosome DNA are commonly used to trace ancestry in this manner. mtDNA is generally passed un-mixed from mothers to children of both sexes, along the maternal line, or matrilineally.[35][36] Matrilineal descent goes back through mothers, to their mothers, until all female lineages converge.

Branches are identified by one or more unique markers which give a mitochondrial "DNA signature" or "haplotype" (e.g. the CRS is a haplotype). Each marker is a DNA base-pair that has resulted from an SNP mutation. Scientists sort mitochondrial DNA results into more or less related groups, with more or less recent common ancestors. This leads to the construction of a DNA family tree where the branches are in biological terms clades, and the common ancestors such as Mitochondrial Eve sit at branching points in this tree. Major branches are said to define a haplogroup (e.g. CRS belongs to haplogroup H), and large branches containing several haplogroups are called "macro-haplogroups".

Simplified human mitochondrial phylogeny

The mitochondrial clade which Mitochondrial Eve defines is the species Homo sapiens sapiens itself, or at least the current population or "chronospecies" as it exists today. In principle, earlier Eves can also be defined going beyond the species, for example one who is ancestral to both modern humanity and Neanderthals, or, further back, an "Eve" ancestral to all members of genus Homo and chimpanzees in genus Pan. According to current nomenclature, Mitochondrial Eve's haplogroup was within mitochondrial haplogroup L because this macro-haplogroup contains all surviving human mitochondrial lineages today, and she must predate the emergence of L0.

The variation of mitochondrial DNA between different people can be used to estimate the time back to a common ancestor, such as Mitochondrial Eve. This works because, along any particular line of descent, mitochondrial DNA accumulates mutations at the rate of approximately one every 3,500 years per nucleotide.[1][37][note 5] A certain number of these new variants will survive into modern times and be identifiable as distinct lineages. At the same time some branches, including even very old ones, come to an end when the last family in a distinct branch has no daughters.

Mitochondrial Eve is the most recent common matrilineal ancestor for all modern humans. Whenever one of the two most ancient branch lines dies out (by producing only non-matrilinear descendants at that time), the MRCA will move to a more recent female ancestor, always the most recent mother to have more than one daughter with living maternal line descendants alive today. The number of mutations that can be found distinguishing modern people is determined by two criteria: first and most obviously, the time back to her, but second and less obviously by the varying rates at which new branches have come into existence and old branches have become extinct. By looking at the number of mutations which have been accumulated in different branches of this family tree, and looking at which geographical regions have the widest range of least related branches, the region where Eve lived can be proposed.

[edit]

Newsweek reported on Mitochondrial Eve based on the Cann et al. study in January 1988, under a heading of "Scientists Explore a Controversial Theory About Man's Origins". The edition sold a record number of copies.[38]

The popular name "mitochondrial Eve", of 1980s coinage,[17] has contributed to a number of popular misconceptions. At first, the announcement of a "mitochondrial Eve" was even greeted with endorsement from young earth creationists, who viewed the theory as a validation of the biblical creation story.[39][40][41][non-primary source needed]

Due to such misunderstandings, authors of popular science publications since the 1990s have been emphatic in pointing out that the name is merely a popular convention, and that the mt-MRCA was not in any way the "first woman".[42] Her position is purely the result of genealogical history of human populations later, and as matrilineal lineages die out, the position of mt-MRCA keeps moving forward to younger individuals over time.

In River Out of Eden (1995), Richard Dawkins discussed human ancestry in the context of a "river of genes", including an explanation of the concept of Mitochondrial Eve.[43] The Seven Daughters of Eve (2002) presented the topic of human mitochondrial genetics to a general audience.[44] The Real Eve: Modern Man's Journey Out of Africa by Stephen Oppenheimer (2003)[38] was adapted into a 2002 Discovery Channel documentary.[45]

Not the only woman

[edit]

One common misconception surrounding Mitochondrial Eve is that since all women alive today descended in a direct unbroken female line from her, she must have been the only woman alive at the time.[42] However, nuclear DNA studies indicate that the effective population size of ancient humans never dropped below tens of thousands.[46] Other women living during Eve's time may have descendants alive today but not in a direct female line.[47]

Not a fixed individual over time

[edit]
After the lineage in black fails to follow on, the new Mitochondrial Eve will go to the next woman who had, at least, two daughters.

The definition of Mitochondrial Eve is fixed, but the woman in prehistory who fits this definition can change. That is, not only can our knowledge of when and where Mitochondrial Eve lived change due to new discoveries, but the actual Mitochondrial Eve can change. The Mitochondrial Eve can change, when a mother-daughter line comes to an end. It follows from the definition of Mitochondrial Eve that she had at least two daughters who both have unbroken female lineages that have survived to the present day. In every generation mitochondrial lineages end – when a woman with unique mtDNA dies with no daughters. When the mitochondrial lineages of daughters of Mitochondrial Eve die out, then the title of "Mitochondrial Eve" shifts forward from the remaining daughter through her matrilineal descendants, until the first descendant is reached who had two or more daughters who together have all living humans as their matrilineal descendants. Once a lineage has died out it is irretrievably lost and this mechanism can thus only shift the title of "Mitochondrial Eve" forward in time.[48]

Because mtDNA mapping of humans is very incomplete, the discovery of living mtDNA lines which predate our current concept of "Mitochondrial Eve" could result in the title moving to an earlier woman. This happened to her male counterpart, "Y-chromosomal Adam", when an older Y line, haplogroup A-00, was discovered.[49]

Not necessarily a contemporary of "Y-chromosomal Adam"

[edit]

Sometimes Mitochondrial Eve is assumed to have lived at the same time as Y-chromosomal Adam (from whom all living males are descended patrilineally), and perhaps even met and mated with him. Even if this were true, which is currently regarded as highly unlikely, this would only be a coincidence. Like Mitochondrial "Eve", Y-chromosomal "Adam" probably lived in Africa. A recent study (March 2013) concluded however that "Eve" lived much later than "Adam" – some 140,000 years later.[50] (Earlier studies considered, conversely, that "Eve" lived earlier than "Adam".)[51] More recent studies indicate that it is not impossible that Mitochondrial Eve and Y-chromosomal Adam might have lived around the same time.[52]

Not the most recent ancestor shared by all humans

[edit]

Mitochondrial Eve is the most recent common matrilineal ancestor, not the most recent common ancestor. Since the mtDNA is inherited maternally and recombination is either rare or absent, it is relatively easy to track the ancestry of the lineages back to a MRCA; however, this MRCA is valid only when discussing mitochondrial DNA. An approximate sequence from newest to oldest can list various important points in the ancestry of modern human populations:

  • The human MRCA. The time period that human MRCA lived is unknown. Rohde et al put forth a "rough guess" that the MRCA could have existed 5000 years ago; however, the authors state that this estimate is "extremely tentative, and the model contains several obvious sources of error, as it was motivated more by considerations of theoretical insight and tractability than by realism."[53] Just a few thousand years before the most recent single ancestor shared by all living humans was the time at which all humans who were then alive either left no descendants alive today or were common ancestors of all humans alive today. However, such a late date is difficult to reconcile with the geographical spread of our species and the consequent isolation of different groups from each other. For example, it is generally accepted that the indigenous population of Tasmania was isolated from all other humans between the rise in sea level after the last ice age some 8000 years ago and the arrival of Europeans. Estimates of the MRCA of even closely related human populations have been much more than 5000 years ago.[54]
  • The identical ancestors point. In other words, "each present-day human has exactly the same set of genealogical ancestors" alive at the "identical ancestors point" in time. This is far more recent than when Mitochondrial Eve was proposed to have lived.[53]
  • Mitochondrial Eve, the most recent female-line common ancestor of all living people.
  • "Y-chromosomal Adam", the most recent male-line common ancestor of all living people.

See also

[edit]

Phylogenetic tree of human mitochondrial DNA (mtDNA) haplogroups

  Mitochondrial Eve (L)    
L0 L1–6  
L1 L2   L3     L4 L5 L6
M N  
CZ D E G Q   O A S R   I W X Y
C Z B F R0   pre-JT   P   U
HV JT K
H V J T

Notes

[edit]
  1. ^ "the synonymous mutation rate of Kivisild et al. [...] estimates the coalescence time of the mtDNA tree overall at ~160,000 kya [...] We present a revised chronology using the complete mtDNA genome rate and an ML approach for the mtDNA tree in Figure 6, with full details of the age estimates and associated 95% confidence regions in Table S5."[1] See: Supplemental Data.
  2. ^ "we estimate the time to the most recent common ancestor (TMRCA) of the Y chromosome to be 120 to 156 thousand years and the mitochondrial genome TMRCA to be 99 to 148 thousand years. Our findings suggest that, contrary to previous claims, male lineages do not coalesce significantly more recently than female lineages."[2]
  3. ^ Two studies published in 2013 had 95% confidence intervals barely overlapping in the neighbourhood of 15 ka, a third study had a 95% confidence interval intermediate between the two others: "99 to 148 ka" according to Poznik, 2013[2] (ML whole-mtDNA age estimate: 178.8 [155.6; 202.2], ρ whole-mtDNA age estimate: 185.2 [153.8; 216.9], ρ synonymous age estimate: 174.8 [153.8; 216.9]), "134 to 188 ka", according to Fu, 2013,[3] and 150 to 234 ka (95% CI) from Soares, 2009.[1]
  4. ^ "Caution: This does not make Mitochondrial Eve the first woman, or the first human, or the first member of a new species. Further Caution: This does not mean that other women alive when Eve was do not have descendants today; they simply do not have living descendants who are descended only through female links. Yet Further Caution: If a person were to be discovered whose mtDNA showed a pattern of mutations of greater time depth, then the status of Mitochondrial Eve would be reassigned to the most recent female ancestor shared by both that person and the person we now call Mitochondrial Eve."[7]
  5. ^ There are sites in mtDNA (such as: 16129, 16223, 16311, 16362) that evolve more rapidly, have been noted to change within intragenerational timeframes – Excoffier & Yang (1999).

References

[edit]
  1. ^ a b c d Soares P, Ermini L, Thomson N, Mormina M, Rito T, Röhl A, et al. (June 2009). "Correcting for purifying selection: an improved human mitochondrial molecular clock". American Journal of Human Genetics. 84 (6): 740–759. doi:10.1016/j.ajhg.2009.05.001. PMC 2694979. PMID 19500773.
  2. ^ a b c Poznik GD, Henn BM, Yee MC, Sliwerska E, Euskirchen GM, Lin AA, et al. (August 2013). "Sequencing Y chromosomes resolves discrepancy in time to common ancestor of males versus females". Science. 341 (6145): 562–565. Bibcode:2013Sci...341..562P. doi:10.1126/science.1237619. PMC 4032117. PMID 23908239.
  3. ^ a b Fu Q, Mittnik A, Johnson PL, Bos K, Lari M, Bollongino R, et al. (April 2013). "A revised timescale for human evolution based on ancient mitochondrial genomes". Current Biology. 23 (7): 553–559. doi:10.1016/j.cub.2013.02.044. PMC 5036973. PMID 23523248.
  4. ^ Endicott P, Ho SY, Metspalu M, Stringer C (September 2009). "Evaluating the mitochondrial timescale of human evolution". Trends in Ecology & Evolution. 24 (9): 515–521. doi:10.1016/j.tree.2009.04.006. PMID 19682765.
  5. ^ "New 'molecular clock' aids dating of human migration history". University of Leeds. 3 June 2009. Retrieved 23 December 2019.
  6. ^ 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. We hypothesize that this bottleneck is caused by cultural changes affecting variance of reproductive success among males."
  7. ^ "Jordan: 'Mitochondrial Eve'". weber.ucsd.edu. 2011. Retrieved 7 January 2012.
  8. ^ Brown WM, George M, Wilson AC (April 1979). "Rapid evolution of animal mitochondrial DNA". Proceedings of the National Academy of Sciences of the United States of America. 76 (4): 1967–1971. Bibcode:1979PNAS...76.1967B. doi:10.1073/pnas.76.4.1967. PMC 383514. PMID 109836.
  9. ^ Ferris SD, Wilson AC, Brown WM (April 1981). "Evolutionary tree for apes and humans based on cleavage maps of mitochondrial DNA". Proceedings of the National Academy of Sciences of the United States of America. 78 (4): 2432–2436. Bibcode:1981PNAS...78.2432F. doi:10.1073/pnas.78.4.2432. PMC 319360. PMID 6264476.
  10. ^ Brown WM (June 1980). "Polymorphism in mitochondrial DNA of humans as revealed by restriction endonuclease analysis". Proceedings of the National Academy of Sciences of the United States of America. 77 (6): 3605–3609. Bibcode:1980PNAS...77.3605B. doi:10.1073/pnas.77.6.3605. PMC 349666. PMID 6251473.
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  12. ^ Cann RL, Wilson AC (August 1983). "Length mutations in human mitochondrial DNA". Genetics. 104 (4): 699–711. doi:10.1093/genetics/104.4.699. PMC 1202135. PMID 6311667.
  13. ^ a b Cann R (May 2010). "All about mitochondrial eve: an interview with Rebecca Cann. Interview by Jane Gitschier". PLOS Genetics. 6 (5): e1000959. doi:10.1371/journal.pgen.1000959. PMC 2877732. PMID 20523888.
  14. ^ Cann RL, Stoneking M, Wilson AC (1987). "Mitochondrial DNA and human evolution". Nature. 325 (6099): 31–36. Bibcode:1987Natur.325...31C. doi:10.1038/325031a0. PMID 3025745. S2CID 4285418.
  15. ^ Vigilant L, Stoneking M, Harpending H, Hawkes K, Wilson AC (September 1991). "African populations and the evolution of human mitochondrial DNA". Science. 253 (5027): 1503–1507. Bibcode:1991Sci...253.1503V. doi:10.1126/science.1840702. PMID 1840702.
  16. ^ Cann RL (1987). "In Search of Eve". The Sciences. 27 (5): 30–37. doi:10.1002/j.2326-1951.1987.tb02967.x. ISSN 2326-1951.
  17. ^ a b c Lewin R (October 1987). "The unmasking of mitochondrial Eve". Science. 238 (4823): 24–26. Bibcode:1987Sci...238...24L. doi:10.1126/science.3116666. PMID 3116666.
  18. ^ Wainscoat J (1987). "Human evolution. Out of the garden of Eden". Nature. 325 (6099): 13. Bibcode:1987Natur.325...13W. doi:10.1038/325013a0. PMID 3796736. S2CID 13187170.
  19. ^ Wilkins A (27 January 2012). "The scientists behind Mitochondrial Eve tell us about the 'lucky mother' who changed human evolution forever". Gizmodo. Retrieved 23 December 2019.
  20. ^ Cann RL (1997). "Chapter 4: Mothers, Labels, and Misogyny". In Hager LD (ed.). Women in Human Evolution. London: Routledge. pp. 75–89. ISBN 9780415108331.
  21. ^ Tierney J (1992). "The Search for Adam and Eve". Newsweek. Carter G. Woodson Institute for Afro-American and African Studies. Archived from the original on 20 March 2015. Retrieved 21 July 2019 – via Internet Archive.
  22. ^ Lemonick MD (26 January 1987). "Everyone's Genealogical Mother". Time. Archived from the original on 23 September 2008. Retrieved 13 May 2013.
  23. ^ Darlu P, Tassy P (1987). "Disputed African origin of human populations". Nature. 329 (6135): 111–112. Bibcode:1987Natur.329..111D. doi:10.1038/329111b0. PMID 3114640. S2CID 4313392.
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