How did only the offspring of mitochondrial Eve survive until 2015?

[trickybilly]

How did only the offspring of mitochondrial Eve survive and the offspring of other contemporary women died until today?

[StringJunky]

I suspect because the introduction of mitochondria conferred a sufficient reproductive advantage to become the totally dominant strain.

[Endy0816]

Sheer numbers of offspring could have "won" the day with a small enough group.

 

Note we could still be related to her contemporaries.

 

ie. Mitochondrial Eve's Daughter(Mitochondrial Strain A) + Lilith's Son(Mitochondrial Strain B) => Samantha(Mitochondrial Strain A)

[pwagen]

From what I've gathered, it's not that all the others' offspring died out, it's just that their offspring failed to produce an unbroken line of female descendants to the present population.

[Delta1212]

From what I've gathered, it's not that all the others' offspring died out, it's just that their offspring failed to produce an unbroken line of female descendants to the present population.

Very much this. Their descendants all either died or had sons. We're all probably equally descended from several women (and men) from the same time period, just not in an unbroken female line. Everyone's mother's mother's mother's mother's etc eventually converges on Mitochondrial Eve.

 

That's different from none of her contemporaries having any living descendants.

[trickybilly]

From what I've gathered, it's not that all the others' offspring died out, it's just that their offspring failed to produce an unbroken line of female descendants to the present population.

I know and that is the question. Why there is only one unbroken linfe of female descendants and not 2, 5 or say 50 today? For example say 50% of the world's population come from Mitochondrial Eve, 20% from a Mitochondrial Doris 30% from a Mitochondrial Samantha. Why is there only one, single surviving line of female descendants and not at least one more? It is logical that some matrilinal lines are more widespread then the others, it's just

how could one maternal line evolutionarily totally "defeat" all other lines and become the only one available?

[John Cuthber]

If there was a "biblical" Eve- the one mother of all humanity because, at the time, there were only two humans, then you would expect us to all share the same mitochondrial DNA.

It only takes a population bottleneck, and a bit of luck to achieve the same effect.

[overtone]

 

 

It only takes a population bottleneck, and a bit of luck to achieve the same effect.

Isn't it a near certainty, only a matter of time and probability?

[Strange]

I know and that is the question. Why there is only one unbroken linfe of female descendants and not 2, 5 or say 50 today? For example say 50% of the world's population come from Mitochondrial Eve, 20% from a Mitochondrial Doris 30% from a Mitochondrial Samantha.

 

Because if you go back further then Eve, Doris and Sam will have a common female ancestor.

[CharonY]

Others have touched by it, but it is the very consequence of the definition. To be precise, she is the most recent common ancestor of all currently living humans in a matrilineal descent. We trace the line back so far that it converges (by definition). And as pwagen already mentioned, the offspring of other women of that time are likely to be around. Only they have a broker maternal line.

[Arete]

It's a common misconception that "mitochondrial eve" and "y-chromosome adam" were actual people. The terms are more concepts rather than references to actual individuals as they are references to the time point at which the particular genetic components (i.e. the mtDNA and the Y chromosome) coalesce back to a single allele. More than one individual could carry this allele, in fact, there are extant species which exhibit homogeneous MtDNA and thus are in a "state of mitochondrial eve" despite there being thousands of individuals of the species simultaneously alive.

 

 

It is logical that some matrilinal lines are more widespread then the others, it's just how could one maternal line evolutionarily totally "defeat" all other lines and become the only one available?

 

The success of a given mtDNA lineage in a bottlenecked population is very likely to be stochastic (i.e. down to chance and probability) rather than due to any form of selection. Research shows us that in populations with limited genetic diversity, genetic drift can actually overwhelm selection, and selectively advantageous alleles can drop out of a population in favor of one which is neutral, or even detrimental.

 

It's quite possible there was nothing special about the human "miochondrial eve" genotype, and it's success was probably down to chance.

[J.C.MacSwell]

It's a common misconception that "mitochondrial eve" and "y-chromosome adam" were actual people.

I am pretty sure they were, by definition for the human population, unless Biology has hijacked the term and changed it from it's original meaning… Can you provide a link that proves otherwise?

 

As per CharonY's definition, there can be one and only one mitochondrial Eve. If she had an identical twin sister, that sister is not Eve. If that sister had an unbroken matronal lineage as well then neither would be Eve…it would be their mother or further back. In theory Eve could be pre-human but I don't believe that's the case.

Edited November 5, 2015 by J.C.MacSwell

[Arete]

I am pretty sure they were, by definition for the human population, unless Biology has hijacked the term and changed it from it's original meaning… Can you provide a link that proves otherwise?

 

As per CharonY's definition, there can be one and only one mitochondrial Eve. If she had an identical twin sister, that sister is not Eve. If that sister had an unbroken matronal lineage as well then neither would be Eve…it would be their mother or further back. In theory Eve could be pre-human but I don't believe that's the case.

 

 

Francisco Ayala wrote a paper attempting to clarify the distinction between gene genealogies and individual genealogies. http://search.proquest.com/openview/c15b7d5d1acb413604acf45778264c9a/1?pq-origsite=gscholar

 

When discussing mtDNA Eve, we are focusing on one component of "her" genome - the mtDNA. The genealogy of this genomic segment can be different from that of an individual, and this gene can be shared by multiple individuals in a population. Thus as the above cited paper demonstrates, we can wind up with a discrepancy between the coalescence of differing genomic components.

 

To repeat and simplify, mtDNA Eve is not an individual, but a specific allele within a population, which could be carried by multiple individuals.

[J.C.MacSwell]

 

 

Francisco Ayala wrote a paper attempting to clarify the distinction between gene genealogies and individual genealogies. http://search.proquest.com/openview/c15b7d5d1acb413604acf45778264c9a/1?pq-origsite=gscholar

 

When discussing mtDNA Eve, we are focusing on one component of "her" genome - the mtDNA. The genealogy of this genomic segment can be different from that of an individual, and this gene can be shared by multiple individuals in a population. Thus as the above cited paper demonstrates, we can wind up with a discrepancy between the coalescence of differing genomic components.

 

To repeat and simplify, mtDNA Eve is not an individual, but a specific allele within a population, which could be carried by multiple individuals.

I don't buy it (literally, I didn't pay to see the rest of it) though it seemed to be a good article. . Perhaps you can provide a quote where Francisco Alaya makes the claim that "Mitochondrial Eve" is not an individual.

 

With all due respect, I think you are misunderstanding (mistaking) his questioning of what he refers to as the Mitochondria Eve hypothesis, that weighs heavily on tracing/estimating Mitochondrial Eve back to living in Africa as recently as 100-200,000 years ago.

 

From Wiki:

"In human genetics, Mitochondrial Eve is the matrilineal most recent common ancestor (MRCA), in a direct, unbroken, maternal line, of all currently living humans, who is estimated to have lived approximately 100,000–200,000 years ago. This is the most recent woman from whom all living humans today descend, in an unbroken line, on their mother’s side, and through the mothers of those mothers, and so on, back until all lines converge on one person. Because all mitochondrial DNA (mtDNA) generally (but see paternal mtDNA transmission) is passed from mother to offspring without recombination, all mtDNA in every living person is directly descended from hers by definition, differing only by the mutations that over generations have occurred in the germ cell mtDNA since the conception of the original "Mitochondrial Eve"."

 

Mitochondria dna is only a small part of our dna, and the Mitochondrial Eve lineage is only one of many, many lines of descent, leading to possibly overstating her case as "mother of all humanity", but whoever she was, she was, until the title shifts to someone more recent. If, say, 3,000 years from now Mitochondrial Eve shifts forward to present day Iceland, that would hardly mean that Homo Sapiens came out of present day Iceland any more than anywhere else. The case for recent Africa is much stronger and more complicated but the same principle applies.

Edited November 7, 2015 by J.C.MacSwell

[puppypower]

One thing that is not addressed is, mitochondrial DNA does not have enough genes to code for all the proteins it needs to do its entire job. The DNA in the cell's nucleus contains supplemental genes that are needed by the mitochondria.

 

If we extrapolate the mitochondria, way back into time, to when it was self sufficient; before merging into the cell, and compare this to modern mitochondria, modern mitochondria have lost genes; self sufficiency, and turning gene over to the cell's DNA for external support.

 

If we combine this with the observation, that some areas of the DNA are more subject to change, while others area are more conservative, the mitochondria appear to have been reducing itself to mostly highly conserved genes. The cellular DNA appears to have most if not all of the more whimsical genes. The mitochondrial DNA is in a conserved steady state that appears in all humans.

Edited November 7, 2015 by puppypower

[Strange]

One thing that is not addressed is....

 

Is it relevant?