'Mitochondrial Eve': Mother of All Humans Lived 200,000 Years Ago

ScienceDaily staff ^ | August 17, 2010 | materials provided by Rice U

[SunkenCiv]

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... "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... For example, the way scientists attempt to date mtEve relies on modern genetic techniques. Genetic profiles of random blood donors 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.

[SunkenCiv]

Alternatives to the Wright-Fisher model:
The robustness of mitochondrial Eve dating
Krzysztof A. Cyran and Marek Kimmel
online 19 June 2010

Abstract: Methods of calculating the distributions of the time to coalescence depend on the underlying model of population demography. In particular, the models assuming deterministic evolution of population size may not be applicable to populations evolving stochastically. Therefore the study of coalescence models involving stochastic demography is important for applications. One interesting approach which includes stochasticity is the O'Connell limit theory of genealogy in branching processes. Our paper explores how many generations are needed for the limiting distributions of O'Connell to become adequate approximations of exact distributions. We perform extensive simulations of slightly supercritical branching processes and compare the results to the O'Connell limits. Coalescent computations under the Wright-Fisher model are compared with limiting O'Connell results and with full genealogy-based predictions. These results are used to estimate the age of the so-called mitochondrial Eve, i.e., the root of the mitochondrial polymorphisms of the modern humans based on the DNA from humans and Neanderthal fossils.

Alternatives to the Wright-Fisher Model and Robustness of Mitochondrial Eve Dating
Marek Kimmel (joint work with Krzysztof Cyran)

Estimation of the time to the most recent common ancestor, or the so-called time to coalescence, is one of the most frequent procedures in population genetics. Several models for calculating the distribution of coalescence time exist, however their applicability is limited to a narrow spectrum of population trajectories. Also, they often rely on assumptions about generation to generation sampling scheme, known to be unrealistic for many populations, including the modern human population. We present a simulation-based approach capable of dealing with different population history scenarios, including populations evolving stochastically with environmental impacts variable in time. This approach allows comparing the branching process model of OConnell with a range of Wright-Fisher type models. We apply our approach to estimate the age of the most recent common female ancestor of humans based on the genetic material from mitochondrial DNA obtained from contemporary humans and extracted from Neanderthal fossils. The results indicate that when Neanderthals are used as an outgroup, the stochastic models based on branching processes provide similar estimates to those obtained with phylogenetic analysis, therefore supporting each other. On the other hand estimates assuming deterministic population growth are considerably higher, indicating that the stochastic demographic effects present in the human population when it was of a relatively small size are not negligible also for inferences dealing with long term history.

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Artist's cross section of a mitochondrion. (Credit: iStockphoto/David Marchal)

mitochondrial eve site:freerepublic.com

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[SunkenCiv]

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[RushIsMyTeddyBear]

http://starwars.wikia.com/wiki/Midi-chlorian

;-)

[null and void]

In before the first ‘they missed the date by 193,986 years’ comment...

[James C. Bennett]

She must’ve been a whore - a common mother, diverse fathers.

[wildbill]

If we assume that all child-bearing ends at age 40, has anyone ever figured out how many ‘greats’ would go before grand mother after 200,000 years?

I’d like to address a prayer of thanks to my forebear.

[SunkenCiv]

:’)

[twhitak]

I thought she had a human father and a cylon mother.

[mountainlion]

I will wait for the rebuttal and peer review. This estimate is off by more than 20,000% of other studies.

[muir_redwoods]

I get this but it always begs the question; She did have a father and a mother of her own, right? wouldn’t her mother have beed due the honor?

[BenLurkin]

IBTHTP

[blam]

I wonder if it included the DNA of this recently found UNKNOWN human?

New Human Species Discovered: Mitochondrial Genome of Previously Unknown Hominins from Siberia Decoded

[James C. Bennett]

The point is, the genetic mutation marker in the mitochondrial DNA has to match - the source of commonality.

[Omedalus]

You’re missing the point. The Mitochondrial Eve hypothesis does not state that she’s the first human female. It states that all humans living today are descendants of this particular female. She may very well have had plenty of cousins or siblings that were all equally human, but they bred less prolifically and their progeny has died out.

[decimon]

Book of Mitochondria, Chapter 1, Verse 1.

[PLMerite]

“I thought she had a human father and a cylon mother.”

There ya go! I was just watching the Final Fracking Episode the other day.

[Radix]

I wrote a paper on Mitochondrial Eve several years ago.

Nothing great, not Peer Review stuff, but still interesting.

Thanks for this and all of your terrific posts.

[mowowie]

Hey Civ, Thanks for ALL of these pings man.
There are a LOT of them! lol.
I don’t usually post but i read most of them.
Good Stuff.

[redhead]

Before The Dawn

[Vaduz]

Mitochondrial Eve’: Mother of All Humans.wouldn’t that make us all a product of incest?.
Another study states that all men with blue eyes came from the same father.
Not sure about all the above.