Mother of all humans lived 200,000 years ago

Aug 17, 2010

The most robust statistical examination to date of our species' genetic links to "mitochondrial Eve" -- the maternal ancestor of all living humans -- confirms that she lived about 200,000 years ago. The Rice University study was based on a side-by-side comparison of 10 human genetic models that each aim to determine when Eve lived using a very different set of assumptions about the way humans migrated, expanded and spread across Earth.

The research is available online in the journal Theoretical Population Biology.

"Our findings underscore the importance of taking into account the random nature of population processes like growth and extinction," said study co-author Marek Kimmel, professor of statistics at Rice. "Classical, deterministic models, including several that have previously been applied to the dating of mitochondrial Eve, do not fully account for these random processes."

The quest to date mitochondrial Eve (mtEve) is an example of the way scientists probe the genetic past to learn more about mutation, selection and other genetic processes that play key roles in disease.

"This is why we are interested in patterns of in general," Kimmel said. "They are very important for medicine."

For example, the way scientists attempt to date mtEve relies on modern genetic techniques. Genetic profiles of random are compared, and based upon the likenesses and differences between particular genes, scientists can assign a number that describes the degree to which any two donors are related to one another.

Using mitochondrial genomes to gauge relatedness is a way for geneticists to simplify the task of finding common ancestors that lived long ago. That is because the entire contains more than 20,000 genes, and comparing the differences among so many genes for distant relatives is problematic, even with today's largest and fastest supercomputers.

But mitochondria -- the tiny organelles that serve as energy factories inside all human cells -- have their own genome. Besides containing 37 genes that rarely change, they contain a "hypervariable" region, which changes fast enough to provide a molecular clock calibrated to times comparable to the age of modern humanity. Because each person's mitochondrial genome is inherited from his or her mother, all mitochondrial lineages are maternal.

To infer mtEve's age, scientists must convert the measures of relatedness between random blood donors into a measure of time.

"You have to translate the differences between gene sequences into how they evolved in time," said co-author Krzysztof Cyran, vice head of the Institute of Informatics at Silesian University of Technology in Gliwice, Poland. "And how they evolved in time depends upon the model of evolution that you use. So, for instance, what is the rate of genetic mutation, and is that rate of change uniform in time? And what about the process of random loss of genetic variants, which we call genetic drift?"

Within each model, the answers to these questions take the form of coefficients -- numeric constants that are plugged into the equation that returns the answer for when mtEve lived.

Each model has its own assumptions, and each assumption has mathematical implications. To further complicate matters, some of the assumptions are not valid for human populations. For example, some models assume that population size never changes. That is not true for humans, whose population has grown exponentially for at least several thousand generations. Other models assume perfect mixing of genes, meaning that any two humans anywhere in the world have an equal chance of producing offspring.

Cyran said human genetic models have become more complex over the past couple of decades as theorists have tried to correct for invalid assumptions. But some of the corrections -- like adding branching processes that attempt to capture the dynamics of population growth in early human migrations -- are extremely complex. Which raises the question of whether less complex models might do equally well in capturing what's occurring.

"We wanted to see how sensitive the estimates were to the assumptions of the models," Kimmel said. "We found that all of the models that accounted for random population size -- such as different branching processes -- gave similar estimates. This is reassuring, because it shows that refining the assumptions of the model, beyond a certain point, may not be that important in the big picture."

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fmfbrestel
2.1 / 5 (7) Aug 17, 2010
Hogwash, Eve was created from Adam's rib 6000 years ago! :-)
blyster
3.4 / 5 (5) Aug 17, 2010
How come everyone is obsessed with finding our mother and nobody talks about our father. Bet he was just a ramblin' man passing through.
TabulaMentis
1.4 / 5 (10) Aug 17, 2010
The book 'Technology of the Gods' by David Hatcher Childress, mentions that ETs (maybe humans) arrived on this planet possibly a million years ago.
TabulaMentis
2.3 / 5 (9) Aug 17, 2010
Maybe one of those horny human's had sex with 'Lucy' back 800,000 years ago?
I fill sorry for that guy when he woke up in the morning and found her laying next to him!
TabulaMentis
2.1 / 5 (7) Aug 17, 2010
Hogwash, Eve was created from Adam's rib 6000 years ago! :-)

Whoever came up with 6000 years ago probably got an F- in math.
TabulaMentis
1 / 5 (7) Aug 17, 2010
Date of 'Lucy's' existence is wrong.

Link to picture of Lucy:

http://www.bander...tour.htm
NeuroPulse
2 / 5 (3) Aug 17, 2010
I don't understand mitochondria Eve. So no other females alive at that time had offspring that bred with Eve's? Only Eve's children breed with each other? I think I need a diagram.
Thrasymachus
4.3 / 5 (3) Aug 17, 2010
I don't understand mitochondria Eve. So no other females alive at that time had offspring that bred with Eve's? Only Eve's children breed with each other? I think I need a diagram.

The theory of evolution insists that if you take any arbitrarily selected group of individual organisms, then there existed at some point in the past an individual reproductive unit that is the ancestor(s) of that group. A reproductive unit can be a single organism in the case of asexual reproduction, or a male and female pair in the case of sexual reproduction. Basically, all the other women either had only sons that survived to reproduce, or had daughters that had only sons, or granddaughters that had only sons, etc.
Skeptic_Heretic
5 / 5 (2) Aug 17, 2010
How come everyone is obsessed with finding our mother and nobody talks about our father. Bet he was just a ramblin' man passing through.

There was a national geographic special on this. We found genetic adam long before we found mitochondrial eve.
I don't understand mitochondria Eve. So no other females alive at that time had offspring that bred with Eve's? Only Eve's children breed with each other? I think I need a diagram.


Within the DNA of all living humans there is a pattern by which shows how our entire line came from an individual. Other brothers and sisters of that individual lived and may have given rise to chimps or other creatures, or entirely died off, but those genetic markers are traceable back to an individual. That individual is conceptually referred to as Mitochondrial eve.
fixer
1 / 5 (2) Aug 17, 2010
I saw the TV show.
Human Journey.
Last year I think, and Eve was an African.
An interesting programme but left me feeling a bit skeptical.
Truth
not rated yet Aug 17, 2010
Maybe one of those horny human's had sex with 'Lucy' back 800,000 years ago?
I fill sorry for that guy when he woke up in the morning and found her laying next to him!

Good Lord, Tabula, I just saw Lucy's pix on the link you provided...Wow, if I woke up with THAT in my grass bed, I'd know I had way too much coconut juice the night before.
Truth
5 / 5 (6) Aug 17, 2010
Hogwash, Eve was created from Adam's rib 6000 years ago! :-)

Whoever came up with 6000 years ago probably got an F- in math.

And an F in geology, oceanography, meteorology, physics, chemistry, biology, ancient history, logical reasoning, genetics, etc...
TabulaMentis
1 / 5 (5) Aug 18, 2010
Hogwash, Eve was created from Adam's rib 6000 years ago! :-)

To be fair it might be possible for the universe to have been created in super fast motion and then slowed down six thousand years ago?
I do not know if that rate would match scientific observations?
It gets murky because we probably live in a multiverse.
So was the multiverse created in six days and six nights or was it our universe.
Ethelred
5 / 5 (4) Aug 18, 2010
To be fair it might be possible for the universe to have been created in super fast motion and then slowed down six thousand years ago?


Somebody said:
Keep and open mind. But not so far open your brains fall out.

I think that covers that speculation.

I just tried tracking down the source of the above statement. There seem to a number of possibilities. So to heck with it. I am putting it under the heading:

Somebody said-

Ethelred
TabulaMentis
1 / 5 (4) Aug 18, 2010
Ethelred:

I do not think the Garden of Eden could have been on this planet, but what do I know!
TabulaMentis
1 / 5 (2) Aug 18, 2010
Hogwash, Eve was created from Adam's rib 6000 years ago! :-)


I have wondered many times about the ETs Garden of Eden. You know those people who are in those flying saucers we hear about. Were they not before us?
Baseline
not rated yet Aug 18, 2010
OH COME ON! Everyone knows that Eden is in Missouri. Ol' Joseph Smith read it on the magical golden plates he dug up.
barakn
2.5 / 5 (2) Aug 18, 2010
Within the DNA of all living humans there is a pattern by which shows how our entire line came from an individual. Other brothers and sisters of that individual lived and may have given rise to chimps or other creatures, or entirely died off, but those genetic markers are traceable back to an individual. That individual is conceptually referred to as Mitochondrial eve.

No, I'm not buying your died-off or split-off theory. Suppose Mitochondrial Eve had a female friend - we'll call her Maeve - who gave birth to only sons. These sons would receive Maeve's mitochondria, but when they reproduced they would not pass these on. We could all be descendants of both Maeve and Eve, but only have mitochondria from Eve.
Skeptic_Heretic
5 / 5 (1) Aug 18, 2010
No, I'm not buying your died-off or split-off theory. Suppose Mitochondrial Eve had a female friend - we'll call her Maeve - who gave birth to only sons. These sons would receive Maeve's mitochondria, but when they reproduced they would not pass these on. We could all be descendants of both Maeve and Eve, but only have mitochondria from Eve.

And Eve would still be the sole source of our mitochondrial DNA, which is the exact attribute that makes her the Mitochondrial Eve. Your hypothetical is a highly likely possibility but it doesn't change the equation at all.

What is your disagreement with that definition? My hypothetical was for the purposes of definition alone, not a statement of what happened.

Chimps could have split off generations before or after mitochondrial eve, (probably very many before). Eve could have been an only child, or maybe she was geographically seperated and procreated with a sibling. Who knows? But the definition of Mito' Eve stands. TBC>
Skeptic_Heretic
5 / 5 (3) Aug 18, 2010
Eve and Adam need not be contemporary.

The two are conceptual based on the structure and prevalence of known mutations within DNA. There is a very limited number of mutations that all haplogroups share, those universal haplogroups determine who/where Adam and Eve came from.

Adam was determined to come from the Rift valley based on a regression of the Y Chromosome. Eve was determined to come from the Rift Valley through the same process but using Mitochondrial DNA.

All Men are related to Adam, All women are related to Eve, logically all humans are related to both. Your issue appears to be the fact that we're dealing with concepts rather than identifiable individuals. The conceptual Adam and Eve are indicators of population origin, not individual identity.
Gawad
not rated yet Aug 19, 2010
Within the DNA of all living humans there is a pattern by which shows how our entire line came from an individual. Other brothers and sisters of that individual lived and may have given rise to chimps or other creatures, or entirely died off, but those genetic markers are traceable back to an individual. That individual is conceptually referred to as Mitochondrial eve.

No, I'm not buying your died-off or split-off theory. Suppose Mitochondrial Eve had a female friend - we'll call her Maeve - who gave birth to only sons. These sons would receive Maeve's mitochondria, but when they reproduced they would not pass these on. We could all be descendants of both Maeve and Eve, but only have mitochondria from Eve.


But...but... Barakn, you're making the very point you are objecting to. That's hilarious!
Brad_Hobbs
1 / 5 (1) Aug 21, 2010
And somewhere, the spiritual remnant of that ancient Eve, is now telling the spiritual remnants of her contempraries "See, I TOLD you not to eat that stuff"
TabulaMentis
Aug 21, 2010
This comment has been removed by a moderator.
DonR
5 / 5 (1) Aug 22, 2010
How come everyone is obsessed with finding our mother and nobody talks about our father. Bet he was just a ramblin' man passing through.


Mitochondrial DNA occurs in the cells' mitochondria, obviously but as opposed to the nucleus, and codes for fundamental functions that don't change much at all over time. It is, therefore, easier to track the history of mDNA. That's the main reason it's used in genealogical 'back-dating'.

I don't understand mitochondria Eve.


You need to consider the occurrence of dead gene lines. It's quite possible that there were Homo sapiens before Mitochondrial Eve, but that all modern humans were descended from her. It just means that the non-Eve gene line died out and the population from which Eve was the base line (remember we still have diversity from the male gamete) populated the planet as it is today.
Skeptic_Heretic
5 / 5 (1) Aug 22, 2010
You need to consider the occurrence of dead gene lines. It's quite possible that there were Homo sapiens before Mitochondrial Eve, but that all modern humans were descended from her. It just means that the non-Eve gene line died out and the population from which Eve was the base line (remember we still have diversity from the male gamete) populated the planet as it is today.
Exactly! Most people get this wrong and assume that the genetic line is fixed.

Homosapiens very well could have been relatively set in it's current form far further back. The Toba eruption dropped the population down to a very small number, and it is quite possible that there have been other bottlenecks in the genetic code.
Barrett
not rated yet Aug 22, 2010
If you guys want an interesting read on where some of these ideas came from, check out Bryan Sykes' book The Seven Daughters of Eve. He also has one on tracing humanity on the male end. It explains all this very well.
jsa09
not rated yet Aug 23, 2010
Trouble with Mitochondrial Eve is that there is no way to confirm it.

Presumably the surveyists checked Kalahari Bush Men and Australian Aborigines with Mongolian Herdsmen and came up with this figure.

However there could still be a thousand or more people on the planet with a more ancient Eve completely separate from everyone else.
Skeptic_Heretic
5 / 5 (1) Aug 23, 2010
Trouble with Mitochondrial Eve is that there is no way to confirm it.

Presumably the surveyists checked Kalahari Bush Men and Australian Aborigines with Mongolian Herdsmen and came up with this figure.

However there could still be a thousand or more people on the planet with a more ancient Eve completely separate from everyone else.

Very true, but in order for that to be a possibility, there would have to be a group of humans, presumably very close to Africa's rift valley, that we haven't encountered yet.
frajo
5 / 5 (1) Aug 24, 2010
Trouble with Mitochondrial Eve is that there is no way to confirm it.

Presumably the surveyists checked Kalahari Bush Men and Australian Aborigines with Mongolian Herdsmen and came up with this figure.

However there could still be a thousand or more people on the planet with a more ancient Eve completely separate from everyone else.

Very true, but in order for that to be a possibility, there would have to be a group of humans, presumably very close to Africa's rift valley, that we haven't encountered yet.
Not necessarily (only) in that region as they could have been migrating around just like the rest of us.
But this group would have had to live without any sexual contact with the rest of us for a time span of many millennia. And that's a bit improbable.
jmcanoy1860
1 / 5 (1) Aug 25, 2010
Maybe one of those horny human's had sex with 'Lucy' back 800,000 years ago?
I fill sorry for that guy when he woke up in the morning and found her laying next to him!


Cocaine's a hell of adrug
jmcanoy1860
not rated yet Aug 25, 2010
OH COME ON! Everyone knows that Eden is in Missouri. Ol' Joseph Smith read it on the magical golden plates he dug up.


Then Smithy was on something more potent than the dude who boinked Lucy. I've been through Missouri. Chiggers (as in insects) on the boys are a LOT of fun.
jmcanoy1860
5 / 5 (1) Aug 25, 2010
Brad Hobbs:

What stuff???


The brown acid.

getgoa
1 / 5 (4) Sep 14, 2010
This phrase could be the focus of many obsessions:

Ecclesiasticus 25:33 found 11
From the woman came the beginning of sin, and by her we all die.
TabulaMentis
not rated yet Sep 14, 2010
This phrase could be the focus of many obsessions:

Ecclesiasticus 25:33 found 11
From the woman came the beginning of sin, and by her we all die.

@getgoa

Who is the mother of God?
TabulaMentis
1 / 5 (1) Sep 14, 2010
@getgoa

I am not talking about Jesus, I am talking about Father in Heaven, his mother? This is a scientific question.
jsa09
not rated yet Sep 21, 2010
...
Not necessarily (only) in that region as they could have been migrating around just like the rest of us.
But this group would have had to live without any sexual contact with the rest of us for a time span of many millennia. And that's a bit improbable.


Not so. The measurement of Mitochondrial transference does not imply a lack of interaction. There could be a large amount of interaction in communities, unless a direct female descendant is tested, she will not be discovered.

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