Editing Mitochondrial Eve (section)

===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>