Mitochondrial Eve, or African Eve as some refer to her, is NOT the mother of all humanity! She is NOT the Biblical Eve!

The original research, in 1980, a mitochondrial DNA study by Wesley Brown, then at the University of California at Berkeley, traced modern humans to a single "mitochondrial Eve," who lived in Africa an estimated 140,000 to 290,000 years ago. This study found unexpectedly small differences among the mitochondrial DNA, signifying a relatively recent origin for modern humans. Brown's data suggested it would take 180,000 to 360,000 years to produce today's diversity starting from a single Eve.

It is this 'single Eve' that needs clarification.

It is true that every human being alive today can trace their mitochondrial DNA (mtDNA) back to just one woman, mitochondrial Eve. It is also true, however, that mtDNA is a small proportion of our total DNA. Nuclear DNA, an equal mixture of DNA from both father and mother, is contained in the nucleus of the cell, mtDNA is external to the nucleus and is inherited solely from the mother. Both sons and daughters inherit mtDNA from the mother, but only daughters can pass it on to their offspring, ie. matrilineal.

It is by tracing back only the mtDNA that we reach the single woman named mitochondrial Eve. Thus Eve is our "matrilineal most recent common ancestor."

The name Eve was perhaps a bad choice, too many connotations with the Biblical Eve, and has led to to some misconceptions.

Mitochondrial Eve did not live in isolation, there were many other women alive at the same time and a lot of their genes have passed down through the ages as well, just NOT the mtDNA. Somewhere along the line of daughters, the mtDNA of these other women have reached an end, either by producing no offspring or by producing only male offspring. All the people alive at the same time as Eve had their own ancestors... including their own most recent common ancestor following the mtDNA lineage, ie they had a "matrilineal most recent common ancestor" which would also be a matrilineal ancestor of ours, but not the "most recent."

There are two points to note here:

(1) Mitochondrial Eve is our "Matrilineal Most Recent Common Ancestor," most recent is the bit to stress here, there are other more ancient ancestors.

(2) It is only the mtDNA that traces our lineage back to mitochondrial Eve, the nuclear DNA does NOT trace back to the same individual.

Indeed, our most recent common ancestor (mrca) has been estimated to be as recent as 3000 years ago, as distinct from our "matrilineal" mrca at 140,000 years ago.

Interestingly, mathematics predicts that mtDNA Eve had to have existed, the DNA studies were more about locating Eve in a particular time and place, the most recent estimate is 140,000 years ago in Africa.

The male counterpart to mitochondrial Eve, Y-chromosomal-Adam is similarly traced using the male only Y-chromosome, and not surprisingly, they did not live at the same time, Adam is estimated to have lived about 60,000 years ago.

I sincerely hope that I've managed to shed some light on what can be a very confusing subject, please leave a comment if you want it expanded on or need a more complete explanation.