Talk:Mitochondrial Eve

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Table of contents

1 Question 2 quibbles 3 Statistics section 4 Planning a fix to a wrong statement in Mitochondrial Eve 5 mitochondrial Eve 6 Surprising Fact? 7 Elaborate

Question

Suppose 100 women lived concurrently with mitochondrial Eve.

What if all of us (humans) are descended from several, or all, of these 100 women ? Then they're all our ancestors, and this becomes easier to understand -- it is a simple bottleneck; we're all descended from the people who were alive then.

Is this idea ruled out by current knowledge ?

But the "tags" that are formed by the genetic variation in the mitochondria that we all share show that, before those 100 ancestors you're thinking of, we all happen to be descended from one female. She was not the only woman alive in her time of course, just the only one who gave rise to a line of female descendents who didn't die out, line by line. For a male version, compare the genealogy of a house, like Nassau, that eventually didn't have any male descendents.

Question: "one woman—possibly one pre-human woman—" a "pre-human" just 100,000 years ago? This bit has been inserted by a fan of Carleton S. Coon I suppose. A last-ditch attempt! Any way to remove it without stirring up a lot of anger?... Wetman 05:48, 28 Jul 2004 (UTC)

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Sorry for the stupid question, but isn't it a bit unlikely that there should have been such an incredibly narrow bottleneck of only one female? I mean, one thousand or one hundred would sound OK, but exactly 1? If we take this mitochondrial similarity stuff as a scientific puzzle, does this sound as a plausible explanation?

By the way, does this not involve a terrible amount of inbreeding? --Tamas 09:14, 28 Jul 2004 (UTC)

Tamas, species doesn't evolve, but individual organisms do. There is no way for the entire human race to evolve collectively. Every new step in evolution starts with one organism. -FredrikM

Species don't evolve? So every species is intact since they arrived, and they all converge on one ancestor of their own? - Jerryseinfeld 11:26, 2 Oct 2004 (UTC)

Is it not possible - at least theoretically- that two or more organisms of a species start to evolve at the same time in the same direction by coincidence? (or because they face the same challenges etc)--Tamas 11:40, 28 Jul 2004 (UTC)

Yes, but the chances of that would be insanely low gracefool 02:13, 30 Jul 2004 (UTC)

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Shouldn't the picture show someone that is much darker skinned? That was always the impression I got when reading on this subject. Also is there any mention of the non-mitichondrial contribution of other contemporaries of Eve to modern humans. Just because the mitochondria came from Eve doesn't mean the entire genetic make-up of all her descendants is solely hers. Rmhermen 13:24, Jul 28, 2004 (UTC)

quibbles

The picture isn't great, 150,000 years ago and decorating herself with jewllery. She looks more like a neolithic asian.

Also there should be some mention that Mitochondrial Eve is not our only, or even a particularly recent common ancestor. Zeimusu 14:52, 2004 Jul 28 (UTC)

I'm in agreement. How did this get to featured article standard? It is useful to have stuff on evolution. I did an emergency save of the , indicated the picture was an artists impression, and changed family tree (based on birth death and marriage records in history) to phylogeny (based on DNA sequences), and noted that there was a population rather than a single foundress. I think the present article is up to standard now. Dunc_Harris|☺ 18:08, 28 Jul 2004 (UTC)

Statistics section

The "Statistics" subsection of the "Challenges to the theory" section seems rather out of place and inadequate for its purpose. First, it isn't a challenge; it's support for the theory based on probability. Second, it asserts that the predicted outcome is "inevitable", making a statement about "a side effect of the dynamics of the system", but doesn't really explain this. (Oh, and "bound to happen inevitably" is redundant.) Third, the phrase "Think about it", as if a moment's thought about complex probability calculations without actual documentation — usually the province of mathematicians — could be expected of the average reader of an evolutionary theory article.

But the worst part is the "Think about it" phrase, followed by an analogy that assumes quite a bit about readers' facility with probability theory. For this analogy to produce results analogous to the "mitochondrial Eve" theory, it appears (to me, at least) that after many generations, we should expect that all the counters would have the same color of only one of the original triangular (female) counters, just by random selection. (The text doesn't state this conclusion; it assumes the reader finds this final state obvious.) "Common sense" might very well lead one to expect that most of the colors would be reproduced into further generations. (It's a race between the expansion of the population, which increases the number of random picks per generation, and the loss of colors in each successive generation, based on the small but finite probability of any given color not being selected in that generation.) Of course, common sense is an unreliable guidepost in probability, which often produces results that defy intuition, but that's exactly why such a terse example provides no real illustration of the point. We need a better illustration, it should go in an appropriate location, and it shouldn't assume probability knowledge that isn't intuitive to anyone but mathematicians. — Jeff Q 09:27, 30 Jul 2004 (UTC)

I concur. It is misplaced and poorly explained. I was of half a mind to just delete it, but a discussion is probably more appropriate. Noisy 11:06, 30 Jul 2004 (UTC)

I agree and have deleted it. It was all factually correct (a truism even) except for the conclusion "it's not evidence for a single Eve". As Jeff Q said, it actually supported the theory. Nurg 07:32, 31 Jul 2004 (UTC)

I'm sorry to see it go completely, as I think it's an interesting and relevant point — just not where it was. I was playing with a simulation script that would illustrate the point made, but I hadn't figured out how to make it available for curious readers, nor have I had much bandwidth to devote to it. It still would have needed rewriting, too. Oh, well. — Jeff Q 03:06, 1 Aug 2004 (UTC)

Planning a fix to a wrong statement in Mitochondrial Eve

Just a note. I don't have a clear idea yet how to make a clean fix to the following broken sentence in the Mitochondrial Eve page: "But only Eve produced an unbroken line of daughters that persists today."

The statement is wrong and misleading. But most importantly that sentence misses an opportunity to make a clear and insightful statement about how Eve relates to the reader.

To see what is wrong and misleading about that statement consider the following counter-example. "There are necessarily at least two people who produced an unbroken line of daughters that persists today. For 1) Eve and 2) at least one man with whom she conceived a daughter produced an unbroken line of daughters that persists today."

Furthermore, consider the following counter-example. "Eve's mother in addition to Eve produced an unbroken line of daughters that persists today." In fact, the empirical evidence suggests that each and every mother of the mother of the mother . . . of the mother in the unbroken line of mothers of Eve also "produced an unbroken line of daughters that persists today."

I don't have a fix for the broken statement yet, but I am thinking along the following lines. "Every person alive today has an unbroken maternal line of mothers reaching back into prehistory. However, the maternal lines of all living persons converge on Eve. And since every person has only one mother, in the generations before Eve, all persons alive today have the same unbroken maternal line of mothers, back to a mother that looked like a chimpanzee, back to a mother that looked like a tree shrew (http://medicine.ucsd.edu/cpa/tupaiasm/Tupaia01.jpg), and beyond." ---Rednblu 20:47, 16 Aug 2004 (UTC)

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"Mitochonrial Eve" is merely the most recent common ancestor of us all. Of course we are all descended in the female line from primitive primates, and from Late Permian eucynodonts. However, since mitochondria are passed down through the female line, we can make no useful statements about the mates of "Mitochondrial Eve". Other females were alive at the time, but their genetic lines died out, by the luck of the draw: "only Eve produced an unbroken line of daughters that persists today." Lots of illuminating links are on the Web. Why not track down the best of them and link them here? As a general rule, it's best to grasp the concept, then make the edits. Wetman 21:06, 16 Aug 2004 (UTC)

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<<Other females were alive at the time, but their genetic lines died out, by the luck of the draw>>

No. That is simply not true. Many other females in Eve's generation passed their genetic lines to people alive today through 1) other than mitochondrial DNA and through 2) great-great-...-grandsons as well as great-great-...-granddaughters.

By the way, check out our friend Pedro II of Brazil. :)) ---Rednblu 23:09, 16 Aug 2004 (UTC)

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mitochondrial Eve

Was "mitochondrial Eve" neanderthal? Please email: igigzechnas@msn.com

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No.

Six of the different Neanderthal remains found by 2004 had enough mitochondrial DNA left in them that analysts could calculate how far back the living humans had a great-great--...grandmother in common with the six different Neanderthals. [1] (http://www.talkorigins.org/faqs/homs/mtDNA.html)

The results of the DNA study comparing analyzed living humans and analyzed Neanderthal remains showed the following.

• • The last mitochondrial ancestor of the analyzed living humans was 150,000 years ago; she would be the Human Mitochondrial Eve.
  • The last mitochondrial ancestor among the analyzed Neanderthal remains was 200,000 years ago; she would be the Neanderthal Mitochondrial Eve. Neanderthal Mitochondrial Eve was a totally different creature from the Human Mitochondrial Eve, though they had a distant common maternal ancestor from whom they both inherited their mitochondrial DNA.
  • The last common mitochondrial ancestor of both Neanderthals and humans lived 500,000 years ago; she would be the last common maternal ancestor of Human Mitochondrial Eve and Neanderthal Mitochondrial Eve. ---Rednblu 00:02, 23 Aug 2004 (UTC)

Surprising Fact?

In the "Chain of Events" section: <<The surprising fact that no other all-female lines have survived from Eve's day is assumed to be an effect of chance rather than selection. >>

Is this really a surprising fact? It would be surprising if we randomly chose a single individual out of all who have lived and THEN discovered that by coincidence this individual was the most recent common female-line ancestor of all living humans...that would be surprising.

What is not surprising at all is that there must have existed just such an individual. If you can determine that we are all descended from some group of humans of size X then you simply perform the operation again and find the common ancestor of THAT group. By definition you will eventually find the individual who is the most recent common female-line (or male line for that matter) ancestor of everyone currently alive.

The reason that "mitochondrial eve" is interesting is simply because due to the way mitochondrial DNA works we can make an estimate of WHEN the most recent common female-line ancestor lived. There was also a most recent common male-line ancestor but we have no way of tracing the male line and estimating when he lived.

Am I right about this? Peeter 18:34, 03 Sep 2004 (UTC)

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Did you consider Y-chromosomal Adam? ---Rednblu 22:03, 3 Sep 2004 (UTC)

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No, you're right, I hadn't considered Y-chromosonal Adam. So, I should amend my earlier statement to say that we may have a way of assessing when our most recent patrilineal male ancestor lived.

But my main point still stands: There is nothing "surprising" about Mitochondrial Eve being our most recent common matrilineal ancestor simply because "The most recent common matrilineal ancestor of all people alive today" is the definition of "Mitochondrial Eve". See [2] (http://www.talkorigins.org/faqs/homs/mitoeve.html) ---Peeter 01:58, 04 Sep 2004 (UTC)

You're right--what's surprising is how recently she lived, not that such a person existed. The way to see this is to work backwards.

Consider the set of all women living today who don't have daughters of their own--call them "the daughters". Now go back one generation and call that group "the mothers". Every daughter has a mother, but some mothers have more than one daughter, so the number of mothers is less than the number of daughters. Go back another generation, to "the grandmothers". Again some grandmothers gave birth to more than one mother, so the number of grandmothers is less than the number of mothers. In general, we see that the number of members of generation N+1 must be ≤ the number of members of generation N. Therefore, if we go back far enough, we come to a generation with only one member--and that's "Eve".

What is surprising is that she lived only 150k years ago, which makes her human, rather than some earlier primate, or reptile, or fish.

—wwoods 20:19, 16 Sep 2004 (UTC)

Elaborate

Is it possible to add more precise data and examples to this article? For example, if 100 women had 100% identical mtDNA could they not all be the mothers of future generations? How does it come to be only one person?

How does this one person theory work? 100 women turn into 100,000 women, then every one of those 100,000 descending from 99 of the original women die, and those surviving turn into 6,391,567,079 descending from the one from the first 100?

Do the other Hominids converge on "one" ancestor? Does every species converge on "one" ancestor?

Thanks - Jerryseinfeld 10:05, 2 Oct 2004 (UTC)

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