It sounds like the term 'Mitochondrial Eve' is similar to Hawking's infamous reference to 'the mind of God'. Scientists use traditional myth as a metaphor for the implications of their discoveries, but the religiously minded (as we used to be) are eager to take the metaphor literally.
Evidence for evolution, Installment 3a: Mitochondrial DNA and Neandertals
by seattleniceguy 48 Replies latest jw friends
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seattleniceguy
AA,
Yes, understanding Mitochondrial Eve correctly takes some serious thinking, and perhaps some charting with a pen and paper. For those who have not yet read it, I recommend that you read this page carefully. It does take work. I had to turn this over for a few days before I accepted and understood it fully.
Euph,
Yes, I think you're right. I'm totally sympathetic to the scientists because in my experience programmers tend to do the same thing. We want to choose terms that are clever and punny and hopefully metaphorical, because they help to make a subject more approachable. In my last project I wrote a specification for a project we playfully dubbed "Munchkin."
After reading aniron's comment above (which I knew was inevitable going into this thread), I began thinking about this tendancy of creationists to pick out bits and pieces of science that they like while ignoring where the science actually leads, and it struck me as enormously intellectually dishonest. Mind you, when I was a Witness, I know that I was guilty of the same thing. But if you're going to read the science, then you ought to read and understand all of it, not just pluck out words and phrases that seem to support your point of view. On the one hand, such a person appeal's to science as an authority, but on the other hand, they don't truly care what the science is actually showing. It's just a tad ironic.
SNG
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DanTheMan
Thanks SNG for another excellent installment. Since you've started this series I've been meaning to go and spend some time on the talk.origins site, but I always end up here, lol
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Carmel
phylogenic recapitulation suggests the original "mother" had gill slits much like a modern day shark. Now my mother was vicious in her quest for approval by Jehovah, so maybe, just maybe.....
carmel
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hooberus
By comparing the mtDNA of humans all over the world, we find that our most recent common female ancestor, by matrilineal descent, lived about 150,000 - 200,000 years ago. It is vitally important to understand that this does not support the concept of a Biblical Eve character - quite the opposite, actually.
The data is actually more consitent with the concept of Biblical Eve than is often presented. The dates calculated "150,000 - 200,000 years ago" are based on calculations which assume "an estimated divergence date between humans and chimpanzees of 4-5 million years ago."* Evolutionists compare the percentage difference in mtDNA between moden humans with the difference between humans and chimpanzees and then based on the assumption of evolution calculate dates such as 150,000 etc. years ago for mtEve. These calculations are not threfore independant empirical evidence against Biblical Eve, but are instead built upon the assumption of a chimpanzee-human common ancestor (ie: the assmption of evolution) to begin with.
* Cell, 90:19?30.
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seattleniceguy
Hello hooberus,
The sources I quoted above indicated that the date for ME was calculated using only the following:
- The observed rate at which mitochondrial mutations occur, and
- The current worldwide diversity of mitochondrial DNA in humans
The mitochondrial DNA in chimpanzees does not bear on when the last common matrilineal ancestor of current humans was.
I don't have access to the Cell issue you cited, but I will check it out the next time I'm at the public library.
SNG
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AlmostAtheist
This article from nature is worth reading: http://www.nature.com/news/2004/041011/pf/041011-2_pf.html
I don't think it explains away the point hooberus made, but it bears on the question.
Dave
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seattleniceguy
Great article, AA!
This may be what hooberus is refering to above, but if so, he missed the point. My article above is discussing mitochondrial DNA and looking for a convergence date between humans looking at only that data.
In the article you linked, it sounds like they were using ubiquitous proteins in nuclear DNA, which are, of course, the perfect tools for this since ubiquitous proteins are in all living creatures. I discussed ubiquitous proteins in my article on cytochrome c.
Of course, the more dating mechanisms we have, the greater confidence we can assign the dates they produce. So this is a really cool piece of the puzzle. Thanks for posting it!
SNG
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hooberus
Hello hooberus,
The sources I quoted above indicated that the date for ME was calculated using only the following:
- The observed rate at which mitochondrial mutations occur, and
- The current worldwide diversity of mitochondrial DNA in humans
The mitochondrial DNA in chimpanzees does not bear on when the last common matrilineal ancestor of current humans was.
Could you please show where your sources calculated dates for mtEve without assuming human-chimpanzee assumptions?
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Midget-Sasquatch
Hooberus,
Chimpanzees don't factor into this at all. The time-point for human chimpanzee divergence is a separate matter....that uses a different method....a popular one is the difference in cytochrome c sequences and its changes are dependant on nuclear DNA mutation rates - not mitochondrial DNA.
LIke SNG wrote you only need to know how much change has happened to the sequence over time and how much time it takes for that change to happen (i.e. rates for human mitochondrial DNA - In the late eighties when the first paper came out, the rate was pegged at about ten times higher than that of nuclear DNA, but since then its been found to be higher...so thats why the age for mtEve was reduced somewhat if you're wondering).
They only had to look at the mitochondrial DNA of the individual people they sampled and find the amount of changes/differences among the sample.
They then fit the samples into a geneological tree (one which fits in all the samples but that requires the least amount of changes overall - you see they're not trying to inflate the age)....that gives a relative outline of which sequences were ancestral or descended from which. The rate can then be used to figure the age.