Mitochondrial Eve?

Question

Can someone explain the concept of "Mitochondrial Eve" to me, in relatively simple terms?

Answer 1

it basically some scientific twist on a load of crud. in simple terms, really. im sure some other answers have gone in and expantiated more. but just on the most basic level thats what it is.

Answer 2

There is a strip of DNA on the mitochondria that doesn't code for proteins.  It is known as the D-loop or hypervariable region.  Theoretically, mutations should randomly accumulate on this region and allow you to roughly date the relative differences.  When all the different types are compared, they all have certain similarities which indicate a common ancestor.  Taken as a whole they date to something like 140,000 years.  That indicates that there is an evolutionary pressure to select for some changes in that particular mitochondria over others.  Otherwise, mitochondria would not be species specific.  The magnitude of that evolutionary pressure is uncertain and its effect on the age is also uncertain but it gives an approximate age.  It doesn't mean she was the only person on Earth and we all descended only from her.  There were likely hundreds of thousands alive at the time that contributed nuclear DNA and mitochondrial but their mitochondrial contributions have been erased by evolution.

Answer 3

The whole Mitochondrial Eve is thing is based on the assumption that the mitochondrial DNA flows strictly down the matriline.  Using this assumption, some scientists (Cann et al) drew up a genetic map tracing the human genome.  Their map was based on determining the oldest mutations on various human populations and they found that Africans had the oldest mutations.  Therefore, they concluded that the first human must have come from Africa.  Since their conclusion was based on following the mitochondrial genetic trail, the press popularized the the findings and called the first human "Mitochondrial Eve".

Answer 4

Mitochondrial Eve (mt-mrca) is the name given by researchers to the woman who is defined as the matrilineal most recent common ancestor (MRCA) for all living humans. Passed down from mothers to offspring for over a hundred thousand years, her mitochondrial DNA (mtDNA) is now found in all living humans: every mtDNA in every living person is derived from hers.

Answer 5

What the gentleman above said is correct, and what is also very interesting, is that it cannot be predicted who will survive in the future, however. It can only be traced backwards in time, after the fact...

So, if you have children, in 100,000 years, your lineage could be among the survivors of Mitochondrial Eve's, as long as they have female children who also survive, and so forth...

Answer 6

The above posters are correct.  We have two basic types of DNA.

Nuclear DNA is the stuff that makes us who we are, genetically.  We get half from Mom and half from Dad, and we are not identical to our parents or our siblings.

Mitochondrial DNA lives in the mitochondrion of the cells.  In s*x cells, the mitochondria live in the egg, not in the sperm (which is basically just nuclear DNA with a tail).   It does NOT undergo sexual reproduction.

Therefore, your mitochondrial DNA is identical to your mother's mtDNA (and your siblings's mtDNA) and your mother's mother's mtDNA, etc .... going back through time.  

The ONLY way mtDNA changes is through mutation.  Over a very long lifespan, these mutations cause mtDNA to look very different from individual to individual.  We can trace these mutations to find out how closely related one population is to another.

ALL of the humans on the planet can trace their mtDNA back to one great-great-great ... etc .... grandmother, "Eve."  This does NOT mean that she was the first human - just that her lineage survived.

A more controversial idea is the concept that mutations, though random, occur on a fairly regular basis through time.  If we accept this idea (it DOES match solid archaeological data), then Eve would've lived about 200,000 years ago.

She almost certainly came from Africa.