Why caps? seriously...

Check out this post Adam and Eve...and Lilith

Yeah... seriously... all caps is for wusses.

But yeah, the Genesis story has been seriously redacted to fit the Christian ideology.  Lilith was indeed the first wife of Adam, and she has many children by him.  This, by the way, takes care of the problem of incest with Even and her sons.  Funny how that works, isn't it?

Anyway, Lilith could not tolerate being treated as inferior to Adam, and rebelled.  God sent down a bunch of angels to help chase her down, and in one version of the story, she ended up becoming something like an evil spirit that came in the night to abduct children from their beds.

[Puts on science hat]

However, we need only examine a basic evolution textbook to understand that it's impossible that there was a "first woman."  Species don't form like that.  In practice, perhaps there was one woman who was more human-like than ape-like-ancestor-like, but there isn't a dividing line between species.  It's a gradual change which can only be identified in reverse.  Quite literally, any human alive could conceivably be the first of a new species, but there will be no way to know until the new species exists.

Kind of makes you wonder, actually.  Much later in our history, and specifically in the Americas, there were various Native American chiefs of whom it was said, "It's hard to find someone who isn't a son or daughter of the king."  I don't know if we can specifically rule out some kind of similar behavior in our prehuman ancestor.  Might mitochondrial Adam have been a powerful fighter who commanded harems with his bigger-than-an-ape's brain?  There's so much that we're guessing about with our oldest human and near-human ancestors.

I'm not sure I think this scenario is particularly likely, but it's interesting to ponder.

Mitochondria is a symbiotic organelle that resides in all of our cells. It carries out the Krebs cycle which is basically the conversion of energy sources to usable energy, so it is an essential part of the living organism. A human foetus receives mitochondria directly via the mothers ovum, presumably all of our mitichondrion DNA was passed to us by our mothers (ie: a female line of inheritance). Males do not pass on mitochondrial DNA simply by virtue of the fact that the mtDNA in their gametes is not seen to survive the early gestational process.

A Matrilinear tree based on the inheritance of mitochondria would suggest a single direct common ancestor exists, a mitochondrial "Eve".

The male counterpart of mitichondrial eve is the Y-Chromosomal Adam, based on the fact that Y chromosomes are inherited strictly by sons, from fathers ; this suggests that a patrilinear tree can, also, be traced to a singular direct common ancestor.

oops... pardon my gaff.  (I wrote about that very subject in my author section, so I can prove I knew that... just a gin-slip there.)

Hmmm... Marco Polo without the nice hat.

No doubt the Y chromosomes chances may have been increased if the "Adam" had lots of sons or grandsons, it's chances may also have been increased if the same were of particularly robust health; but yeah it comes down ultimately to his progeny having outlived all those of his contemporaries by whatever means, they may have just been lucky or you could, as I'd be inclined to, insert a time-symmetric quantum state selection process over many universes here . In any case a sufficient number of surviving Y-chromosome carriers were living at the point in history when all alternatives had disappeared.  

Couldn't we just use simple math?  I don't see the point in bringing other universes into the equation when the math works just fine in this one.

I am amazed about how much I have learned being on line in the atheist community activly since 01. I have known for years that "Lilith" was the first claimed woman of the OT and not Eve.

BUT, having said that, it doesn't hurt to keep bringing that up, because most Christians falsely believe Eve was, because they don't know their history.

No sweat though, "Eve" or "Lilith" hocus pocus does not exist. BOTH are merely figments of Jewish/Christian mythology.

Well Brian, I guess some of us come help ourselves. We like to attack the argument at every level where we see a blatantly stupid assumption or illogical step...

Say what!?!

So... um... pretty much... um... a basic simulation of the basic mathematical laws of natural selection demonstrates that both genetic ancestors are possible.... so um...

[facepalm]

Eloise, I am pretty sure that none of these common ancestor figures, whether calculated by matrilineal ('Eve'), patrilineal ('Adam') or either sex ('MRCA') are assuming a ''bottleneck'. Obviously a bottleneck would make it likely that these ancestors would have lived more recently, but a bottleneck is not required for this idea to work.

My understanding is that there are a number of scenarios which could have led to rather distant "Adam" and "Eve."   Any one is individually relatively improbable to very improbable, but all fall well below the threshold of plausibility needed to justify their inclusion in the discussion.  If you like, you can think of it anthropically.  Ancestral Adam and Eve, by all accounts, appear to have existed.  Therefore, there is a scenario, no matter how unlikely, that did happen.

Maybe I'm opening a can of worms I'm not ready to deal with, but your multiverse explanation just sounds like a complicated metaphor for visualizing the event.  I get that you're not arguing for a multiverse.  I just can't for my life figure out why you didn't simply use three dimensional space to explain a visual metaphor.  I'm lost as to what a multiverse adds to the discussion.

Wait a damn minute.  Don't chimps (and plenty of other mammals less closely related to us) engage in intragroup infanticide?  You kill the male offspring of your defeated rival and not only do you remove breeding competition for yourself and your sons on down the road, you also get the females to begin ovulating again.  Homo sapiens was widely exhibiting the same behavior in warfare only a few centuries ago.  We might have not killed the boys everytime (though the Jews did), but we certainly did cut their balls off and put them to work as eunuchs, right?  Maybe the apparent bottleneck is just the result of a long stretch of tribal level conquests.  No huge, single human die-off is required, just a really successful military campaign that takes place over the course of generations.  Eventually you get enough migration to allow the mutations that form the various haplogroups to develop.

Yeah, of course, I didn't explicitly say it but I meant that I was referring to the Y chromosome and the mitochondrial organelle establishing through two separate hominid bottlenecks, or at least one did, most likely the Y chromosome.

Anyhow, I have no argument with you on this, my knowledge here is cursory and I only have an impression that a few things like the lack of genetic diversity in homosapiens and the fingerprints of events on our DNA are strongly in favour of bottleneck scenarios over alternative types of drift. Still I'm happy to agree it's not necessary, if I needed to assert that it was in order to believe what I believe about I'd be making too many bald assumptions, anyway.

Now I should go back to trying to compose a concise answer to Hamby's question, so far it's looking a bit too waffly.

There certainly is evidence for bottlenecks in our history, but the ability to trace back all people alive today to some common ancestor does not in any way depend on this.

As I said before, it simply depends on the observation that as we trace back thru the generations, everytime any two or more individuals share the parent you are tracing thru, the cohort reduces. Thus eventually you can expect it to shrink to one. A simple mathematical necessity.