Human Origins: Let's Talk Mitochondrial Eve

Since Mitochondrial Eve came up on a thread yesterday in reference to a human bottleneck, I've been trying to understand this bit of science, and I am getting nowhere.First let me say that I don't have any problem with the idea that the mitochondria is inherited through the mother all the way back, so that it can only go back to a single female for each and every one of us. Father's mothers don't count and all that. That much I get.What I don't get is not all that clear or easy to put into words. I understand that samples of mitochondria were taken from individuals all over the planet, and that this is what led to this particular woman in Africa 150 to 200 thousand years ago. I've read some discussions about this supposed first woman and all the speculations surrounding that, but that is the CONCLUSION of this study that was done, and what I don't get is the specifics of that study, the evidentiary and mental route taken to arrive there. I'm trying to picture what was actually DONE in this study, and it's driving me crazy. I want to be able to TRACK all the thinking that went into arriving at the conclusion.Sorry if the question is vague, but I'd really appreciate anyone's effort to sort it out and answer it.{Edit:
Like, what exactly are they seeing when they look at the mitochrondria of each person in the study?Like, some question is raised about the value of a mere sample, no matter how diversely collected, considering that it's still only a very small portion of the living human population.Like, how much guesswork is involved and at what points in the study.Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Replaced? Only ones that survived, doesn't that mean? And what's important about this anyway? I just don't get it. It seems whimsically arbitrary to track this phenomenon. Yeah, but I see no conceivable significance to this. It's just an odd artifact of genetic structure. I get it, I get it, but so what? It's not as if billions of women hadn't existed and passed on their genes. It's just that one particular woman's mitochondria happened to survive a complex chain of genetic transmission -- and all that means is that there just happened to be an unbroken chain of mother-daughter transmission, an accidental and not at all significant fact that I can see. I see absolutely no significance to this fact. I can't see how this indicates a bottleneck. I just don't get the whole scenario.I also do not see how anyone could possibly figure out the exact SOURCE of the particular woman. Location, timing etc. So they found this one kind of mitochondria in all these people all over the world. Well, it does apparently indicate, according to the basics about mitochondria, that it does all go back to just one particular woman back sometime or other, but how on earth could anybody guess where? And again, why does it matter????Edited by Faith, : No reason given.Edited by Faith, : No reason given.Edited by Faith, : No reason given.

Sorry if I phrased it wrong. I think I get all that. I just don't get why it MATTERS that there just happened to be this one unbroken chain of mother-daughter transmission. It's not as if all the other women whose mitochondria DIDN'T get passed on, because the chain of daughters was broken, didn't pass on their genes, or didn't exist. Millions, billions of others. Where's the "bottleneck?" It seems like an arbitrary oddness of genetics that ends up meaning nothing.Edited by Faith, : No reason given.

I'd really like someone to walk me through the process of thinking that led back to this woman, including all the evidence gathered along the way. I get the basic idea about the inheritance of mitochondria from mother to daughter.It would help to understand how it is known that there is only one type of mitochondria per woman, perhaps; how it was surmised which population group it originated in etc.

OK that's helpful. Something to do with probabilities then. Differences in the DNA? Don't get it.

Probably answered somewhere I overlooked but anyway:Is it the idea that ALL women living today have this particular mitochondrial DNA?Were all the samples taken of women? Men DO have this mitochondrial DNA, right, they just don't pass it on, right?