My impression was that mitochondrial Eve referred to a real specific individual in the past, though not the first woman, not the only woman alive at the time. I thought that the “mitochondrial Eve” of everyone one alive today is not the same individual as everyone alive a few thousand years in the past, or a few thousand years in the future. However I still thought she was a real single individual. However an article I just read in pbs said:
“ … mitochondrial Eve — which statistically speaking is not one woman, but a group of closely related women — emerged approximately 200,000 years ago in the Makgadikgadi basin.“
Surely this is wrong. Because this “ group of closely related women” would trace back to a single woman, and that woman, not the “group of closely related women” would be the true “mitochondrial Eve” of everyone alive today. So am I wrong? Is this group mitochondrial Eve, or is mitochondrial Eve one single individual who is the ancestor of this group?
It would be good to provide a link to this article so we could see any context. But on it’s face, this claim would seem to be wrong, for the reason you give.
Defining Mitochondrial Eve, most likely a single person, as the origin of modern humans is silly. Owing to genetic recombination there was also a Hemoglobin Beta Betty, a Cytochrome C Sam, a Little-Piece-of-Junk-DNA-George, and so on. It is unfortunate that so many people insist that a new species always arises from one individual.
I think they may be talking about the ancestral node on a mitochondrial tree, which would be a genotype, not an individual. The tree can’t trace back further than that common genotype to the common ancestor that had that genotype.
Right ok. So you mean “mitochondrial Eve” was indeed an actual individual woman, who would be prior to this “group of woman” (prior to the “ancestral node”) but we can’t trace back to that individual. Because all the sources I’ve read refer to “mitochondrial Eve” as an individual not a group. For example I’ve read that MT Eve almost certainly never met y-chromosomal Adam, even asking this question wouldn’t make sense unless she was an actual individual woman. Asking if a group of women could have met y-chromosomal Adam wouldn’t even make sense.
Yeah I totally understand that she wasn’t the first woman or only woman alive at the time, nor was she the “origin of modern humans.” I was just confused because I’d been told by over and over again by multiple geneticists that there must be a single woman who is the ancestor of the Mitochondria of all humans alive today, whom we call “mitochondrial Eve”. One geneticist while answer the question if the Mitochondria of all humans alive today could potentially trace back to more then one woman told me:
“As for your question about mitochondria coming from multiple women, if you go far enough back in the past, those multiple women will trace to a single ancestor. It is only if you suppose that some mitochondria came from Mars or something like that would you conclude multiple origins for our mtDNA.”
This must be the case because of the pattern of genetic inheritance. I believe it’s called coalescence? It’s almost mathematically certain that there must be a single woman (although she’d be part of a large population). So I was surprised when this article seemed to be suggesting that Mitochondrial Eve was the name given to a group of women.
If I may just add: by ancestral node do you mean the fact that on the mitochondrial tree we would eventually reach a small group of women who may in fact have been genetically identical to her with respect to their mtDNA (e.g., if the group included her mother, a sister, and several aunts), BUT only one of them is the woman we call “mitochondrial Eve” because the other woman’s mitochondrial lineages died off (had no children, only sons, or daughters who had only sons)z Eventually, all of the women in the population will have her as the earliest g’g’g’grandmother in common.
Exactly. Or you could consider the ancestral node as just being every woman who had that exact haplotype, spread over many generations. MtEve would just be the first woman to have that haplotype, but the tree doesn’t resolve that finely.
Don’t know why it wouldn’t. Could you have met the women who lived in Milwaukee in 1872?
No. What we reach is a haplotype. Because there is on average less than one mutation per generation, many of mtEve’s descendants (though not her mother, sisters, or aunts) would have the same haplotype. MtEve is the first woman to have that haplotype, That’s all.
What I mean is that there’s is a common misunderstanding amongst creationists that MT Eve met Y-Adam and where a couple. But a creationist I’ve been debating with said that nobody thinks mitochondrial Eve isn’t an individual but a group of women. So I was saying that you can’t say it’s a group of women and then also ask did she meet Y-Adam. Even asking if she lived at the same time as Y-Adam implies that she is a singular individual.
Right, so all mitochondria I the current human populations descends from the ancestral node, but the ancestral node is still not mitochondrial Eve. There is a singular woman who mitochondrial Eve.
Ah right ok. And unless every woman in every generation has 1 or more daughters (which is statistically extremely unlikely) then it’s a certainty that we will all ultimately descend from one individual woman at some point in the distant past who is mitochondrial Eve.
Yeah, and I would disagree. A group of women could easily meet or not meet someone. A group of women could easily live at a particular time (or within a particular range of time). This is not in any way a contradictioni. But of course mtEve is a single person anyway.
Absolutely, quite right. I meant that some creationists think mitochondrial Eve and Y-Adam were a paired couple. Which implies mitochondrial Eve was a single person. Which is correct, but the chance they lived at the same time and were a paired couple is ridiculous. The funny thing was one creationist was implying the above, while another was saying mitochondrial Eve is a name for a population.
Um, maybe make your example a bit more distant. The earliest-born person who I ever met was a relative of my mother, Mertice Knapp Henry (“Aunt Mertie”). I met her about 1960 when my mother took us to Aunt Mertie’s retirement apartment in Doylestown, Pennsylvania. She was then about 86, a cheerful and lively old woman and and a total character. She was born in upstate New York in 1874. Charles Darwin was alive when she was born and the U.S. president then was Ulysses S. Grant.
MT Eve was an individual women in Africa. But obviously not the only woman, or a “first woman” as some maintain
that it’s mathematically certain that all the MT in the human population must trace back to a single woman. It not possible that we trace back to a group without being able to trace further back to a single woman
she’s not a fixed individual over time. So if she lived in say, 150,000 BC, then she obviously wouldn’t be the MT Eve of everyone alive at that time, not for people alive 149,500, but once she did become the MT Eve over everyone alive she would remain an ancestor of all mitochondria from then on, although eventually another women would be called MT Eve because they would be the most recent common ancestor.
Yes, MT Eve would be an individual woman, but not necessarily the only woman nor the first woman. If we jumped forward a few hundred thousands years from now it is possible that the MT Eve of that future time could be alive right now.
I think that is a safe conclusion. There may be situations where the most recent common ancestor of mitDNA is a common ancestor of two species.
Correct. MT Eve is sort of like the boxing heavyweight champion belt. It gets passed on to the next champ.
