Mitochondrial Eve (mtDNA)

Mitochondrial Eve

From Wikipedia, the free encyclopedia
Haplogroup Modern humans
Early diversification.PNG
Possible time of origin c. 100–230 kya[1]
Possible place of origin East Africa
Ancestor n/a
Descendants Mitochondrial macro-haplogroups L0, L1, and L5
Defining mutations None

In human genetics, the Mitochondrial Eve (also mt-Eve, mt-MRCA) is the matrilineal most recent common ancestor (MRCA) of all currently living humans, i.e., 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. Mitochondrial Eve lived later than Homo heidelbergensis and the emergence of Homo neanderthalensis, but earlier than the out of Africa migration,[2] but her age is not known with certainty; a 2009 estimate cites an age between c. 152 and 234 thousand years ago (95% CI);[3] a 2013 study cites a range of 99–148 thousand years ago.[4]

Because mitochondrial DNA (mtDNA) is almost exclusively passed from mother to offspring without recombination (see the exception at paternal mtDNA transmission), most mtDNA in every living person differs only by the mutations that have occurred over generations in the germ cell mtDNA since the conception of the original “Mitochondrial Eve”.

The male analog to the Mitochondrial Eve is the Y-chromosomal Adam, the member of Homo sapiens sapiens from whom all living humans are patrilineally descended. Rather than mtDNA, the inherited DNA in the male case is the nuclear Y chromosome. Mitochondrial Eve and Y-chromosomal Adam need not have lived at the same time.[5]

As of 2013, estimates for mt-MRCA and Y-MRCA alike are still subject to substantial uncertainty; thus, Y-MRCA has been estimated to have lived during a wide range of times from 180,000 to 581,000 years ago[6][7][8] (with a most likely age of between 120,000 and 156,000 years ago, roughly consistent with the estimate for mt-MRCA[4][9]).

The name “Mitochondrial Eve” alludes to biblical Eve.[10] This has led to repeated misrepresentations or misconceptions in journalistic accounts on the topic. The title of “Mitochondrial Eve” is not permanently fixed to a single individual, but rather shifts forward in time over the course of human history as maternal lineages become extinct. Unlike her biblical namesake, she was not the only living human female of her time. However, by the definition of Mitochondrial Eve, her female contemporaries, though they may have descendants alive today, do not have any descendants today who descend in an unbroken female line of descent.

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