marylandnaturegirl

This show premeires Sunday at 9pm Eastern Time on the Discovery Channel:

The advert for it reads:


On the Discovery Channel at 9:00 p.m. Sunday, April 21. "The Real Eve" As
noted in one add, "Could every human being be genetically related to ONE
WOMAN who lived 150,000 years ago?" Finally, science draws back the veil on
who we really are, not some fragment of a pathetic egocentric god, but a
product of natural processes and real people in an unfolding story far more
beautiful and far more impressive.


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This reminds me of the material in the Dawkins book "River Out of Eden"
For details and more times it will air go to:

<a href="http://dsc.discovery.com/convergence/realeve/realeve.html" target="_blank">Web Page for The Real Eve on Discovery Channel</a>

tronvillain

150,000 years ago? Sounds like Mitochondrial Eve, our most recent common female ancestor with respect to matrilineal descent. We probably have a much more recent common female ancestor.

An interesting thought: Our most recent common female ancestor is either the mother or the daughter of our most recent common male ancestor.

[ April 20, 2002: Message edited by: tronvillain ]</p>

Daydreamer

To recent - Mitochondrial/Chloroplastial endogenesis occured before the single-cellular/multicellular split, over 1.5 billion years ago I believe.

tronvillain

In other words, you didn't understand what I said. Mitochondrial Eve is defined as our most recent common female ancestor with respect to matrilineal descent, just as Y-chromosome Adam is defined as our most recent common male ancestor with respect to patrilineal descent. It has absolutely nothing to do with "mitochondrial/chloroplastial endogenesis."

[ April 20, 2002: Message edited by: tronvillain ]</p>

lpetrich

That's right about this endosymbiosis -- mitochondria and chloroplasts are descended from different sorts of bacteria; alpha-proteobacteria and cyanobacteria.

However, there was no single origin of multicellularity; it has happened several times.

Bill

In any case, there is good evidence of an "evolutionary bottleneck" occurring about 70,000 years ago. This was a point when (apparently) most of humanity died off, and only a few thousand people were left, in small groups living in isolated places. Inbreeding led to rapid evolutionary change, from which what we now call "racial characteristics" would appear to have emerged. It wasn't enough to split humanity into several new species, but if it had gone on for a few tens of thousands of years more without further inbreeding, it might have.

=====

Anyway, I'm not really sure where they get these sorts of wild claims from, anyway. I'm certain that most people of white European descent have a common ancestor within the past 2,000 years. From my personal research, I'm all but convinced that the vast majority of white Europeans are all descendants of Charlemagne in one way or another. Try getting population figures for Europe from about 800 CE to the present, and then look at average family sizes, birth and death rates, and inter-class breeding patterns. My personal path to Charlemagne presumably stretches back through a great-great-great grandmother who was the illegitimate daughter of a Scottish baron (its really hard to tell for sure if these old family stories have any real truth to them...). I have another possible connecting line that stretches back through the Dutch upper class in the 15th century. And a third family story asserts that some footman (my ancestor) ran away to America with an English Duke's daughter (also my ancestor). My German ancestors are the only line I don't know enough about to speculate on a connection to Charlemagne, but all things considered, Charlemagne has lots of decendants in Germany.

My point here is that most people with some sort of obvious common heritage are probably very closely related (i.e., within the past 2,000 years at the most) because breeding populations of long ago began fairly small, interbred closely, with large family sizes (and corresponding high mortality rates), and thus common ancestorship spread widely throughout virtually the entire population.

The only thing that forces us to look back as much as 150,000 years is if we wish to tie in all of the separated races (people from various locations), from Eskimos down to Aborigones and from Chinese all the way around to Myans and Incans. Within any given civilized population, there are obviously common ancestors a lot closer than 150,000 years!

== Bill

tronvillain

As I pointed out, there is a difference between a common ancestor and a common ancestor with respect to matrilineal or patrilineal descent. We definitely don't have to go back anywhere near to 150,000 years to find a universal common ancestor, but to to find the most resent common female ancestor with respect to matrilineal descent, apparently we do.

cricket

TronV, will you explain this?

tronvillain

Now that I think about it, our most recent common female ancestor could also potentially be the mate, sister, or contemporary of our most recent common male ancestor. Of course, for the latter to be the case would require extremely unlikely timing.

Peez

I would just like to note, as there is sometimes confusion about this, that "mitochondrial Eve" is not our only ancestor from that time. No doubt others of "Eve's" generation have passed on some of their genes to our generation. However, none of "Eve's" contemporaries' mitochondrial genes have survived to the present.

Peez