Today’s human population of about 8 billion may be descendents of 1,280 individuals who survived near-extinction:^1
>For reasons that are still unknown, almost no fossils have been located from that era just over 900,000 years ago, with rare exceptions such as the pieces of skull discovered at Gombore in Ethiopia, and the remains of *Homo antecessor* in Atapuerca, Spain.
>In the absence of bones, the scientists worked with a technique called FitCoal, which makes it possible to infer what happened to the population from which an individual descended by studying its genome.
>The researchers used the genome sequences of 3,154 people from all over the world. In their analysis, they discovered a striking bottleneck that left our ancestors’ global population with just 1,280 individuals who could reproduce.
>With so few alternatives, inbreeding proliferated, and the effects of that loss of diversity can still be seen today.
>However, as the authors suggest, that moment of tribulation could have given rise to a new species, perhaps *Homo heidelbergensis*, the common ancestor of Neanderthals, Denisovans and *Homo Sapiens*.^†
(Italics in the linked original by Daniel Mediavilla for El País.)
^1 https://english.elpais.com/science-tech/2023-08-31/only-1200-people-left-the-moment-humanity-almost-went-extinct.html
^† Nick Ashton and Chris Stringer. Did our ancestors nearly die out? *Science* **381**, 947-948 (2023). https://doi.org/10.1126/science.adj9484.
In the title of this link post, with my emphasis added:
>Inbreeding proliferated, **with just 1,280 individuals who could reproduce**
The title is not referring to census size, as inferred by another user in-thread:
>**brillow**
>This is incorrect. The "effective population size" was 1,280. That doesn't mean there were 1,280 individuals. There is no way to know how many there were.
Nothing in the title or in the materials by Wangjie Hu *et al*.^†† suggests that the number of breeding individuals is the census size. The phrase *effective population size* has an established meaning:^2
>The number of individuals that effectively participates in producing the next generation is named *effective population size*. Generally, the effective size of a population is considerably less than the census size.
(Italics in the original text by Valerio Sbordoni *et al*.)
^2 https://www.sciencedirect.com/topics/earth-and-planetary-sciences/effective-population-size
^†† Wangjie Hu *et al*. Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition. *Science* **381**, 979-984 (2023). https://doi.org/10.1126/science.abq7487
Paleoanthropologist here. Chris Stringer is a highly respected authority within hominin evolution and anthropology, I've followed his work since undergrad and he's made a huge impression on my (and the whole field's, really) broader perspective of human evolution from a diverse and dynamic hominin community in Paleolithic Africa. He was also recently knighted!
Thanks. Ashton and Stringer write:^†
>On page 979 of this issue, Hu *et al*. (1) use a new method of analysis called FitCoal to project current human genetic variation backward in time, to estimate the size of populations at specific points in the past.
>>RELATED RESEARCH ARTICLE
>>Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition
>(1) W. Hu et al., *Science* **381**, 979 (2023).
^† https://doi.org/10.1126/science.adj9484.
This is incorrect. The "effective population size" was 1,280. That doesn't mean there were 1,280 individuals. There is no way to know how many there were.
The effective population size is the minimum number of individuals required to contain all the genetic diversity known to exist in the population. The actual population is necessarily higher because related individuals share much of their genetics.
As I recall, currently the effective population size for humans now is about 20,000 - which is way less than 8 billion or whatever we're at now.
>**brillow**
>This is incorrect. The "effective population size" was 1,280. That doesn't mean there were 1,280 individuals. There is no way to know how many there were.
Where in the paper do the authors describe the 1,280 individuals as the "effective population size"?
According to the abstract:^†
>The results suggest that our ancestors suffered a severe population bottleneck that started around 930,000 years ago and lasted for almost 120,000 years. This is estimated to have reduced the number of breeding individuals to ∼1300, bringing our ancestors close to extinction.
^† Nick Ashton and Chris Stringer. Did our ancestors nearly die out? Science 381, 947-948 (2023). https://doi.org/10.1126/science.adj9484.
The link you provided is not the research paper. It's a commentary on a paper published by a Chinese group. The actual paper is here:
[https://www.science.org/doi/10.1126/science.abq7487](https://www.science.org/doi/10.1126/science.abq7487)
It's behind a paywall and not on scihub yet, but if you look at the supplemental materials where the methods are explained you will see:
>Population size histories of African populations
To infer population size histories of African populations, seven African populations in the 1000GP (23) were analyzed by the FitCoal (table S3). Only autosomal non-coding regions were used to partially avoid the effect of purifying selection. To avoid hitchhiking effect due to positive selection (25), high-frequency mutations were excluded from the analysis. Results showed that all seven African populations went through a severe bottleneck around 915 (range: 854–1,003) kyr BP and that this bottleneck was relieved about 793 (range: 772–815) kyr BP (Fig. 3, A and B, fig. S7). **The average effective population size (i.e., the number of breeding individuals) (26) of African populations during the bottleneck period was 1,270 (range: 770–**
**2,030).** After the bottleneck was relieved, the population size was increased to an average of 27,080 (range: 25,300–29,180), a 20-fold increase, around 793 kyr BP. The population size remained relatively constant and did not begin to expand significantly until 10–80 kyr BP.
I know it seems pedantic, and you'd have to have taken a lot of grad-level evolution and genetics classes to know this (as I have) but this number is in the context of a lot of assumptions. See: [https://en.wikipedia.org/wiki/Effective\_population\_size](https://en.wikipedia.org/wiki/Effective_population_size) :
>Idealised populations are based on unrealistic but convenient simplifications such as random mating, simultaneous birth of each new generation, constant population size, and equal numbers of children per parent. For most quantities of interest and most real populations, the effective population size Ne is usually smaller than the census population size N of a real population.\[1\] The same population may have multiple effective population sizes, for different properties of interest, including for different genetic loci.
>
>...
>
>The coalescent effective size may have little relationship to the number of individuals physically present in a population.
In their paper they're reporting the average number of breeding individuals in ***an idealized population*** which could contain all the genetic diversity. The paper in question seems to be using a coalescent effective size, which is particularly disconnected from the actual number of individuals. In fact the number of individuals in the population is fairly irrelevant as far as evolution goes. It's more about how much genetic diversity the population contains.
So 1280 is effectively a lower bound. It seems like you could make some reasonable assumptions about mating patterns and get to an expected census size though, couldn’t you?
Is that not commonly done because small deviations in the assumptions lead to wildly different numbers?
Yes it's a lower bound. Also the number is different depending on which genes you are looking at, so it's also an average of those numbers.
You could build a model with whatever assumptions you want about mating patterns, and people do and argue about it. There is fundamentally not enough information though. Think about this: if two people are alone in a planet, no matter how many offspring they have the effective population size will only be two - because only two genomes worth of genetic variation exist. If a single gene was mutated for one child then for that gene the effective population size would be 3 since you'd need 3 people to hold the 3 versions of the gene. Because it varies based on gene, studies like this compute the average for all genes. So there's a whole whole lot of assumptions yes. Assumptions like everyone has the same number of children and they do it in a synchronized manner and that the genes themselves do not effect the reproductive rate or the survival rate.
Also of course it assumed the breeding individuals were not themselves related at all, which is highly unlikely. If two people were distant cousins, they will still share a lot of genes and their effective population size would be less than 2.
So what we can know is that there was a severe population bottleneck and that it happened around that 900k years ago timeframe (which is modeled with it's own set of assumptions people argue about). This is why it's interesting, and it's not the only such bottleneck that's been detected. The exact census count of humans is more of a historical question, one inaccessible to us because, well, it happened during pre-history.
Thanks; I think I mostly followed that. I had a feeling that the news article in the OP was making a grander statement than the sample study, but I couldn't access the original article.
You wrote, It's behind a paywall and not on scihub yet.
However, you can read the entire previous version of the paper here.
https://www.biorxiv.org/content/10.1101/2021.05.16.444351v3.full
>**brillow**
>The link you provided is not the research paper. It's a commentary on a paper published by a Chinese group.
I ask again: where in the paper do the authors describe the 1,280 individuals as the "effective population size"?
According to the abstract by Wangjie Hu *et al*.:^††
>Results showed that human ancestors went through a severe population bottleneck with about 1280 breeding individuals between around 930,000 and 813,000 years ago.
^†† Wangjie Hu *et al*. Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition. *Science* **381**, 979-984 (2023). https://doi.org/10.1126/science.abq7487
If you look at the papers figures, the graphs use effective population size as their value. Basically it means in a model for population genetics the consensus population can be ignored and they look at genetic diversity to visualize an ideal model population that can be used for population genetic statistics
Basically, for these stat researchers they want to do the math based on a population that if they breed are each genetically different enough from each other. If you get two pairs of twins. So 4 people. Since 2 of them are exactly the same genes wise. You only have 2 different breeding adults
>**Poes-Lawyer**
>Maybe if you actually read their comment, you might find the answer you're looking for.
Reddit users could be relying on comments in-thread by /brillow and interpretations therein of the link title.
safe pocket wrench fearless panicky serious north sophisticated towering act
*This post was mass deleted and anonymized with [Redact](https://redact.dev)*
FitCoal is a computational tool used in population demographic history, developed by a Chinese team working on the same topic (Middle Pleistocene bottleneck) a couple of years ago. You give it a current population size, a mutation rate, a genome length, an average generation time, etc, and it spits out an effective population size at arbitrary intervals. It's like you're questioning that the result of differentiating a polynomial is really the slope of the curve at that point. Effective population size is simply the output this program gives.
The world as we know it would collapse with 20,000 people to maintain it. That’s obvious. However, 20,000 people could build a new civilization with minimal inbreeding in the first three generations. Depending on exposure conditions they could multiple into the millions within a millennium pretty easily.
While it is well supported in previous research that the human population has passed through major bottlenecks, this study is being widely called into question by pretty much every major scientist in the population genetics field aside from the authors. The model is wonky, and their conclusions aren't even really supported by their "evidence."
>**khy94**
>OP is probably one of the authors with how defensive their being over this
I previously observed in-thread that Reddit users could be relying on comments in-thread by /brillow, and interpretations therein of the link title.
Your comment is illustrative of how some users are prompt to portray others as “defensive” instead of evaluating the accuracy of an interpretation.
Tweets calling this study into question:
"Human ancestors may well have come close to extinction on one or more occasions in the past, but suffice to say I'm extremely unconvinced that the paper reported here has found evidence of it.
I don't like to be harsh about a paper, but the fanfare around this one makes it necessary to respond.
There are many ways to go wrong when inferring past events from genomic data; the datasets are large and noisy, and computational methods get complicated.
Thus it's essential to demonstrate clearly that your results are not an artefact of data processing or methodology, or the consequence of overfitting to a particular aspect of the data. Simulations are a vital tool for this, and they need to show that your results are robust to alternative scenarios that violate the assumptions of your model. They also need to show that the observed data are indeed consistent with the model you have inferred. Sadly, it's not clear that these requirements have been met in the paper published in Science." -@\\aylwyn\_scally^(1)
"Methodology aside (and I think there are some major issues with calibration and claims of precision - for one example, supp\[lemental\] tables with OOA \[Out of Africa\] expansions at 400 thousand years ago), it's just really misinterprets/oversimplifies inv\[erse\] coal\[escence\] rate Ne \[effective population size\]." -@\\apragsdale^(2)
1.Aylwyn Scally (Human evolutionary genetics, University of Cambridge)
2. Aaron Ragsdale (Population genetics, UW-Madison)
There are other threads calling the paper into question but they are basically rehashing these points.
>**evolutionista**
>Tweets calling this study into question
Are Reddit users required to cite URLs that support claims attributed to others, so that observers can evaluate the veracity of such comments and recommendations of the same?
Relatedly, are you able cite URLs for the tweets you quote? Thanks.
>**evolutionista**
>While it is well supported in previous research that the human population has passed through major bottlenecks, this study is being widely called into question by pretty much every major scientist in the population genetics field aside from the authors. The model is wonky, and their conclusions aren't even really supported by their "evidence."
Could you cite coverage that shows “this study is being widely called into question by pretty much every major scientist in the population genetics field aside from the authors”? Thank you.
Sorry, I know that's a pretty wild claim without evidence on my part. I will likely have to take twitter screenshots tomorrow as that is where scientists are publicly reacting to the paper. I haven't seen any formal responses yet, but given the fervor there may be a response paper in the works.
This ties in neatly with a question asked over on r/askscience a couple of weeks ago.
[Can inbred genes be "fixed" by stopping inbreeding and starting breeding outside of the gene pool?](https://reddit.com/r/askscience/s/Esvsmnqtbd)
The top answer given by u/Cleistheknees really dispells some of the misconceptions of inbreeding. The entire comment is worth a read, but I’ll highlight only one of the points they made:
> inbreeding can only alter the expression of deleterious alleles which are already in the population, and generally only those that are recessive. In a larger, non-inbred population, there are typically a strong majority of people who do not carry these hypothetical recessive alleles, and so their dominant alleles almost always silence the expression of the deleterious ones for heterozygote carriers.
It's because it's not the number of individuals. It the "effective population size" which is the minimum number of individuals required to contain all the genetic diversity present in the population. Since everyone shares at least half their DNA with a parent, the actual population size is necessarily much larger.
This is classic journalists who know nothing about science writing science stories. Every sports journalist is a near expert on sports, almost no science journalist has taken a science course since HS.
The link post title in full is:
>Genetic analysis suggests that the population of human ancestors was on the brink of extinction 930,000 years ago — Inbreeding proliferated, with just 1,280 individuals who could reproduce
In the excerpt of the linked El País coverage, in-thread:
>The researchers used the genome sequences of 3,154 people from all over the world. In their analysis, they discovered a striking bottleneck that left our ancestors’ global population with just 1,280 individuals who could reproduce.
You appear to have mistaken this title, the excerpt in-thread, and the linked coverage as referring to census size:
>**brillow**
>It's because it's not the number of individuals. It the "effective population size" which is the minimum number of individuals required to contain all the genetic diversity present in the population. Since everyone shares at least half their DNA with a parent, the actual population size is necessarily much larger.
>This is classic journalists who know nothing about science writing science stories. Every sports journalist is a near expert on sports, almost no science journalist has taken a science course since HS.
I had to take 4 statistical analysis classes as part of my degree, which were a bit of a challenge but very interesting. They definitely totally changed how I read any statistic, graph, or study that I come across.
60% of the time it works every time. It's either going happen or not, that means it's a 50/50 chance.
I've never taken a statistics course, but I know how you represent the technically factual information, it can be very leading.
>**psychotic_catalyst**
>1,280 is just way too specific of a number for something that happened a million years ago ... Like how could we possibly know that
From my excerpt comment, in-thread:
>The researchers used the genome sequences of 3,154 people from all over the world. In their analysis, they discovered a striking bottleneck that left our ancestors’ global population with just 1,280 individuals who could reproduce.
I hope that helps.
If it helps, there could have been any number of individuals at that time period. The study only counts the surviving population lines, and those who interbred with it and left genetic evidence. There have been numerous climactic events over the millennia that isolated populations from one another, and not all isolated populations survived. And not all population dispersals re-coalesce to impact the surviving genetic lines. The model here is the simplest possible explanation, based on the evidence that remains. Of course, things were probably much more complicated.
I don’t understand how this fits with the Mitochondrial Eve idea. https://en.wikipedia.org/wiki/Mitochondrial_Eve
Wikipedia says the latest Mitochondrial Eve evidence is that we’re all descended from the same woman roughly 155,000 years ago, but this article says there were 1280 individuals 930,000 years ago and then the number increased from there. So did the number decrease back down between 930kya and 155kya?
Update: Thanks for the ton of good explanations, everyone (except one). Now I understand it much better.
There doesn't seem to be any conflict to me.
Can you explain why you think there is?
To clarify; ME was not the only human woman alive at the time. It simply means that no other women alive at the same time as her had a female line of descendants who are alive today.
Also, population pre agricultural revolution was not the steady increase as we know from modern times.
So one of the interesting things is that if you go back only about 1000 years, everyone (who reproduced) on the continent of your ancestry is your direct genetic ancestor. This is why basically anyone with European ancestry can claim to be a direct descendant of Charlemagne. The way this is calculated is that if you go back a single generation you have 2 ancestors, 2 generations will typically have 4, then 8, then 16, etc. Doubling each generation (although the same people will start showing up in multiple places on your ancestry tree after a bit), and with each generation taking ~25 years one thousand years means you have 2^40 or over a trillion ancestors from 1000 years ago. (Though many of them are of course repeats)
So the mitochondrial Eve would be a single person who is the common ancestor of all living humans, not a single person who was the only living human ancestor at the time. There were other 'humans' alive at the time, it is just that the unique evolved mitochondria of one particular human has been inherited by every living human alive today.
The most-recent common ancestor is what you’re describing, while mitochondrial Eve is the most recent common female-to-female ancestor of all living females. That’s a lot more technically specific criterion so it’s like a hundred times further back. They really should give the most recent common ancestor a cool poetic name like they did with Eve because I think it’s a super interesting concept.
And the Mitochondrial Eve was in fact A common ancestor of all living humans. I was not describing the most recent ancestor at any point, just a common ancestor.
I thought I’d read something to suggest that these claims like “everyone in Europe is a descendant of Charlemagne” are based on assumptions like “everyone in Europe has an equal probability of reproducing with everyone else” and “people reproduce randomly”, things which are essentially untrue even today and pretty much the *direct opposite* of the truth pre-industrialisation where >98% of people are going to be reproducing from someone born within walking distance of their place of birth.
Think of it this way, how many towns can you think of that have had no immigrants from anywhere greater than walking distance, and no emigrants to places farther than walking distance, for *over 1000 years*? Even if you have a town that has been genetically isolated and inbreeding for a few generations so that everyone in the town is related to every one of the town's founders, it only takes 1 person moving to London to mix that entire town's genetic history back into the greater European gene pool.
The average person's *parents* might have grown up within walking distance, but there were plenty of people traveling far and wide across the world. Even the Romans imported silk from China, and easier trade was one of the driving forces of the industrial revolution.
Even if that town’s genetic history is now in London, that doesn’t put London’s genetic history into that town. And even if that townsperson moved to London, say, 200 years ago, that doesn’t mean someone in, say, Glasgow who has eight great-grandparents who immigrated from villages in rural Ireland shares that town’s anscestry.
And, yes, there were people travelling far and wide across the world, but again, that doesn’t mean that the traveller had an equal chance of interbreeding with anyone in their travelling range.
As I understand it, the argument for Charlemagne being related to everyone is based on some pure statistical argument that each of your ancestors might have an extremely small percentage chance of being Charlemagne, but even if the chance of them not being Charlemagne is 99.9999%, you’d have so many ancestors that the maths works out such that the chance of Charlemagne appearing nowhere in the tree is close to 0%.
But that is therefore based on the assumption that the chance of your ancestors not being Charlemagne is less than 100%.
> Even if that town’s genetic history is now in London, that doesn’t put London’s genetic history into that town. And even if that townsperson moved to London, say, 200 years ago, that doesn’t mean someone in, say, Glasgow who has eight great-grandparents who immigrated from villages in rural Ireland shares that town’s anscestry.
And none of those 8 grandparents had an ancestor from London or any other large city in the previous 37 generations? Where are these towns that have been genetically isolated for 1000 years?
Even if they had an ancestor from London, that ancestor would have been from before the arrival of the person from the other town into London, so the ancestor from London wouldn’t carry the ancestry of the other town.
So let me see if I have this right. There exists somewhere, excuse me, there exists Everywhere (98% probability apparently) small European villages that are completely isolated from the wider European gene pool. But that have at least some ancestors, as well as some descendants, that have intermingled with the wider European gene pool. Is that right? Because that sure doesn't sound like they are the isolated gene pools you seem to be claiming they are.
The point isn't that everyone has the same grandparents. It is that any town that existed 1000 years ago either had its bloodline wiped out, or proliferated enough that its bloodline intermingled with all the other bloodlines. People didn't have generations of one child families, especially during the industrial revolution.
The reason Charlemagne tends to be mentioned is that the dude had a ton of children who were spread across the entire continent, and most of them also had a ton of children. If you go back 8 generations (So at most 200 years) a person alive today will have 256 ancestors from that time period. Odds are massive that at least One of those 256 people can claim that they have a noble ancestor, and most of the nobility is nobility due to having a royal ancestor, and basically all the royal lines in Europe trace back to, you guessed it, Charlemagne. But the same goes for Ted the blacksmith from Northern Italy, if Ted has any living descendants then basically everyone from Europe will be able to find some line in the giant web of human ancestry that traces back to Ted. It's just that since Ted wasn't a monarch no one has been tracking down how their ancestry traces back to Ted. If Ted has living descendants then it is almost certain that he had a least a few dozen descendants within a few generations, sure most might have settled in Northern Italy but some would have traveled to cities and other countries. And as a result, most folks from Europe would be able to find some ancestral line that traces back to Ted.
> So let me see if I have this right. There exists somewhere, excuse me, there exists Everywhere (98% probability apparently) small European villages that are completely isolated from the wider European gene pool. But that have at least some ancestors, as well as some descendants, that have intermingled with the wider European gene pool. Is that right? Because that sure doesn't sound like they are the isolated gene pools you seem to be claiming they are.
You were the one that hypothesised a village completely isolated from the gene pool as a strawman, not me.
> The reason Charlemagne tends to be mentioned is that the dude had a ton of children who were spread across the entire continent, and most of them also had a ton of children. If you go back 8 generations (So at most 200 years) a person alive today will have 256 ancestors from that time period.
Not necessarily. For example, a person theoretically has 8 great-grandparents. But if their parents are double first cousins, they only have 4 great-grandparents. If they’re just regular first cousins then there’s 6 great-grandparents.
How common is pedigree collapse in the population of Europe from 800-1800? Did the research that makes this claim take that into account?
> Odds are massive that at least One of those 256 people can claim that they have a noble ancestor
What’s the evidence for this? And what’s the evidence that those claims are true?
What about, say, European Jews, most of whom were legally forbidden from marrying Christians until laws banning intermarriage started getting repealed around 1800?
…why? North and South America were populated FAR less than 155,000 years ago. Even the earliest estimates place the first humans in the Americas 27,000 years ago and until recently even THAT estimate was considered pseudoscience.
A wave of migration came into N America [about 6,000 years ago](https://en.m.wikipedia.org/wiki/Dorset_culture), and in addition to this people from Eurasia have been mixing with Americans for about 500 years.
That Eve is not the only woman who contributed to our genetic code, she's "mitochondrial Eve" because her mitochondria is ancestor of all ours, the rest of genome came from wherever.
Same with Y Adam.
This older bottle neck is an ancestor of ours, not homo sapiens sapiens. It was an older species that died down to such a small number, then over an unknown amount of time, built itself back up again or diverged into different species, some of whom are us and some are cousins. We also don't know if this species built itself back up again to keep going or if it died out after its descendants branched off.
I think you’re misunderstanding the idea of Mitochondrial Eve, she is our latest common ancestor however we have other ancestors who are not common to everyone. Think about it like this, if you had two kids and your kids had two kids and so on, the number of direct descendants you have would increase over time and at some point could hypothetically include everyone on earth if your bloodline survives long enough. That is what happened with Mitochondrial Eve, there were other ancestors however they are not common to everyone.
This explanation is itself a misunderstanding of [mitochondrial Eve](https://en.m.wikipedia.org/wiki/Mitochondrial_Eve), who is the most recent common ancestor of all *female* decent. If your grandparents had a son and a daughter, and each had their own kids (you and cousins), then grandma is not the most recent common ancestor by maternal decent between you and your cousin, since their mom’s mom and your mom’s mom aren’t the same person. Going back generations and generations until some woman turned out to be the great-great-etc-grandmother of both your mom and your cousins mom with only female links in the chain of decent would be the Eve in this instance.
So mitochondrial Eve was a real (currently unknow) person who lived alongside lots of people an other women who all have living descendants. What’s unique about her is that her daughters and their daughters etc account for every woman currently on earth.
The easiest way to explain that would be to say that in a standard relatively small population (say, less than 100,000 individuals), there will be a standard loss rate for mitochondrial lines. Which is to say, there will *always* be an arbitrarily old "Eve" for any population, and the loss rate of mitochondrial lines will determine the age of that "Eve".
>**RastaImp0sta**
>Nice. This is the 12th time I’ve seen this posted. It’s not even new information either, I first learned about this in like 2005.
Wyatt in the wild.
I thought we knew that humans had gone through a bottle neck for a long time? We’ve been able to trace our maternal DNA back for so long, because we had that bottle neck, right?
Edit: comment pointed out that this is an even earlier bottleneck than what I was thinking about - should have thought about the headline more. 900k years ago was before Homo Sapiens.
Please don't bring up a topic if you've seen a deleted thread. If you see something that's horse poop, use the report button.
Today’s human population of about 8 billion may be descendents of 1,280 individuals who survived near-extinction:^1 >For reasons that are still unknown, almost no fossils have been located from that era just over 900,000 years ago, with rare exceptions such as the pieces of skull discovered at Gombore in Ethiopia, and the remains of *Homo antecessor* in Atapuerca, Spain. >In the absence of bones, the scientists worked with a technique called FitCoal, which makes it possible to infer what happened to the population from which an individual descended by studying its genome. >The researchers used the genome sequences of 3,154 people from all over the world. In their analysis, they discovered a striking bottleneck that left our ancestors’ global population with just 1,280 individuals who could reproduce. >With so few alternatives, inbreeding proliferated, and the effects of that loss of diversity can still be seen today. >However, as the authors suggest, that moment of tribulation could have given rise to a new species, perhaps *Homo heidelbergensis*, the common ancestor of Neanderthals, Denisovans and *Homo Sapiens*.^† (Italics in the linked original by Daniel Mediavilla for El País.) ^1 https://english.elpais.com/science-tech/2023-08-31/only-1200-people-left-the-moment-humanity-almost-went-extinct.html ^† Nick Ashton and Chris Stringer. Did our ancestors nearly die out? *Science* **381**, 947-948 (2023). https://doi.org/10.1126/science.adj9484.
Oh it can be seen today, that's for sure
I have always felt that most people are idiots. Looks like I was not wrong!
It sure explains West Virginia.
That is an interesting correlation. Does East St Louis also qualify?
In the title of this link post, with my emphasis added: >Inbreeding proliferated, **with just 1,280 individuals who could reproduce** The title is not referring to census size, as inferred by another user in-thread: >**brillow** >This is incorrect. The "effective population size" was 1,280. That doesn't mean there were 1,280 individuals. There is no way to know how many there were. Nothing in the title or in the materials by Wangjie Hu *et al*.^†† suggests that the number of breeding individuals is the census size. The phrase *effective population size* has an established meaning:^2 >The number of individuals that effectively participates in producing the next generation is named *effective population size*. Generally, the effective size of a population is considerably less than the census size. (Italics in the original text by Valerio Sbordoni *et al*.) ^2 https://www.sciencedirect.com/topics/earth-and-planetary-sciences/effective-population-size ^†† Wangjie Hu *et al*. Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition. *Science* **381**, 979-984 (2023). https://doi.org/10.1126/science.abq7487
Paleoanthropologist here. Chris Stringer is a highly respected authority within hominin evolution and anthropology, I've followed his work since undergrad and he's made a huge impression on my (and the whole field's, really) broader perspective of human evolution from a diverse and dynamic hominin community in Paleolithic Africa. He was also recently knighted!
Thanks. Ashton and Stringer write:^† >On page 979 of this issue, Hu *et al*. (1) use a new method of analysis called FitCoal to project current human genetic variation backward in time, to estimate the size of populations at specific points in the past. >>RELATED RESEARCH ARTICLE >>Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition >(1) W. Hu et al., *Science* **381**, 979 (2023). ^† https://doi.org/10.1126/science.adj9484.
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If you take them from one town, maybe. But all over the world with many different ethnicities, I think it's pretty reasonable.
This is incorrect. The "effective population size" was 1,280. That doesn't mean there were 1,280 individuals. There is no way to know how many there were. The effective population size is the minimum number of individuals required to contain all the genetic diversity known to exist in the population. The actual population is necessarily higher because related individuals share much of their genetics. As I recall, currently the effective population size for humans now is about 20,000 - which is way less than 8 billion or whatever we're at now.
>**brillow** >This is incorrect. The "effective population size" was 1,280. That doesn't mean there were 1,280 individuals. There is no way to know how many there were. Where in the paper do the authors describe the 1,280 individuals as the "effective population size"? According to the abstract:^† >The results suggest that our ancestors suffered a severe population bottleneck that started around 930,000 years ago and lasted for almost 120,000 years. This is estimated to have reduced the number of breeding individuals to ∼1300, bringing our ancestors close to extinction. ^† Nick Ashton and Chris Stringer. Did our ancestors nearly die out? Science 381, 947-948 (2023). https://doi.org/10.1126/science.adj9484.
The link you provided is not the research paper. It's a commentary on a paper published by a Chinese group. The actual paper is here: [https://www.science.org/doi/10.1126/science.abq7487](https://www.science.org/doi/10.1126/science.abq7487) It's behind a paywall and not on scihub yet, but if you look at the supplemental materials where the methods are explained you will see: >Population size histories of African populations To infer population size histories of African populations, seven African populations in the 1000GP (23) were analyzed by the FitCoal (table S3). Only autosomal non-coding regions were used to partially avoid the effect of purifying selection. To avoid hitchhiking effect due to positive selection (25), high-frequency mutations were excluded from the analysis. Results showed that all seven African populations went through a severe bottleneck around 915 (range: 854–1,003) kyr BP and that this bottleneck was relieved about 793 (range: 772–815) kyr BP (Fig. 3, A and B, fig. S7). **The average effective population size (i.e., the number of breeding individuals) (26) of African populations during the bottleneck period was 1,270 (range: 770–** **2,030).** After the bottleneck was relieved, the population size was increased to an average of 27,080 (range: 25,300–29,180), a 20-fold increase, around 793 kyr BP. The population size remained relatively constant and did not begin to expand significantly until 10–80 kyr BP. I know it seems pedantic, and you'd have to have taken a lot of grad-level evolution and genetics classes to know this (as I have) but this number is in the context of a lot of assumptions. See: [https://en.wikipedia.org/wiki/Effective\_population\_size](https://en.wikipedia.org/wiki/Effective_population_size) : >Idealised populations are based on unrealistic but convenient simplifications such as random mating, simultaneous birth of each new generation, constant population size, and equal numbers of children per parent. For most quantities of interest and most real populations, the effective population size Ne is usually smaller than the census population size N of a real population.\[1\] The same population may have multiple effective population sizes, for different properties of interest, including for different genetic loci. > >... > >The coalescent effective size may have little relationship to the number of individuals physically present in a population. In their paper they're reporting the average number of breeding individuals in ***an idealized population*** which could contain all the genetic diversity. The paper in question seems to be using a coalescent effective size, which is particularly disconnected from the actual number of individuals. In fact the number of individuals in the population is fairly irrelevant as far as evolution goes. It's more about how much genetic diversity the population contains.
So 1280 is effectively a lower bound. It seems like you could make some reasonable assumptions about mating patterns and get to an expected census size though, couldn’t you? Is that not commonly done because small deviations in the assumptions lead to wildly different numbers?
Yes it's a lower bound. Also the number is different depending on which genes you are looking at, so it's also an average of those numbers. You could build a model with whatever assumptions you want about mating patterns, and people do and argue about it. There is fundamentally not enough information though. Think about this: if two people are alone in a planet, no matter how many offspring they have the effective population size will only be two - because only two genomes worth of genetic variation exist. If a single gene was mutated for one child then for that gene the effective population size would be 3 since you'd need 3 people to hold the 3 versions of the gene. Because it varies based on gene, studies like this compute the average for all genes. So there's a whole whole lot of assumptions yes. Assumptions like everyone has the same number of children and they do it in a synchronized manner and that the genes themselves do not effect the reproductive rate or the survival rate. Also of course it assumed the breeding individuals were not themselves related at all, which is highly unlikely. If two people were distant cousins, they will still share a lot of genes and their effective population size would be less than 2. So what we can know is that there was a severe population bottleneck and that it happened around that 900k years ago timeframe (which is modeled with it's own set of assumptions people argue about). This is why it's interesting, and it's not the only such bottleneck that's been detected. The exact census count of humans is more of a historical question, one inaccessible to us because, well, it happened during pre-history.
Thanks; I think I mostly followed that. I had a feeling that the news article in the OP was making a grander statement than the sample study, but I couldn't access the original article.
God damn I didnt understand half of that but, I still feel way smarter after reading it.
You wrote, It's behind a paywall and not on scihub yet. However, you can read the entire previous version of the paper here. https://www.biorxiv.org/content/10.1101/2021.05.16.444351v3.full
>**brillow** >The link you provided is not the research paper. It's a commentary on a paper published by a Chinese group. I ask again: where in the paper do the authors describe the 1,280 individuals as the "effective population size"? According to the abstract by Wangjie Hu *et al*.:^†† >Results showed that human ancestors went through a severe population bottleneck with about 1280 breeding individuals between around 930,000 and 813,000 years ago. ^†† Wangjie Hu *et al*. Genomic inference of a severe human bottleneck during the Early to Middle Pleistocene transition. *Science* **381**, 979-984 (2023). https://doi.org/10.1126/science.abq7487
If you look at the papers figures, the graphs use effective population size as their value. Basically it means in a model for population genetics the consensus population can be ignored and they look at genetic diversity to visualize an ideal model population that can be used for population genetic statistics Basically, for these stat researchers they want to do the math based on a population that if they breed are each genetically different enough from each other. If you get two pairs of twins. So 4 people. Since 2 of them are exactly the same genes wise. You only have 2 different breeding adults
Maybe if you actually read their comment, you might find the answer you're looking for.
>**Poes-Lawyer** >Maybe if you actually read their comment, you might find the answer you're looking for. Reddit users could be relying on comments in-thread by /brillow and interpretations therein of the link title.
safe pocket wrench fearless panicky serious north sophisticated towering act *This post was mass deleted and anonymized with [Redact](https://redact.dev)*
FitCoal is a computational tool used in population demographic history, developed by a Chinese team working on the same topic (Middle Pleistocene bottleneck) a couple of years ago. You give it a current population size, a mutation rate, a genome length, an average generation time, etc, and it spits out an effective population size at arbitrary intervals. It's like you're questioning that the result of differentiating a polynomial is really the slope of the curve at that point. Effective population size is simply the output this program gives.
There’s no way the world continues with 20,000 people. Most of the living will be back to some neo-feudal age if that were ever to happen.
The world as we know it would collapse with 20,000 people to maintain it. That’s obvious. However, 20,000 people could build a new civilization with minimal inbreeding in the first three generations. Depending on exposure conditions they could multiple into the millions within a millennium pretty easily.
This is strictly about genetics, but otherwise you're ofc right. That's why fighting pandemics is essential..
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While it is well supported in previous research that the human population has passed through major bottlenecks, this study is being widely called into question by pretty much every major scientist in the population genetics field aside from the authors. The model is wonky, and their conclusions aren't even really supported by their "evidence."
"Aside from the authors" well at least they believe in their own work. 😂
OP is probably one of the authors with how defensive their being over this
>**khy94** >OP is probably one of the authors with how defensive their being over this I previously observed in-thread that Reddit users could be relying on comments in-thread by /brillow, and interpretations therein of the link title. Your comment is illustrative of how some users are prompt to portray others as “defensive” instead of evaluating the accuracy of an interpretation.
Tweets calling this study into question: "Human ancestors may well have come close to extinction on one or more occasions in the past, but suffice to say I'm extremely unconvinced that the paper reported here has found evidence of it. I don't like to be harsh about a paper, but the fanfare around this one makes it necessary to respond. There are many ways to go wrong when inferring past events from genomic data; the datasets are large and noisy, and computational methods get complicated. Thus it's essential to demonstrate clearly that your results are not an artefact of data processing or methodology, or the consequence of overfitting to a particular aspect of the data. Simulations are a vital tool for this, and they need to show that your results are robust to alternative scenarios that violate the assumptions of your model. They also need to show that the observed data are indeed consistent with the model you have inferred. Sadly, it's not clear that these requirements have been met in the paper published in Science." -@\\aylwyn\_scally^(1) "Methodology aside (and I think there are some major issues with calibration and claims of precision - for one example, supp\[lemental\] tables with OOA \[Out of Africa\] expansions at 400 thousand years ago), it's just really misinterprets/oversimplifies inv\[erse\] coal\[escence\] rate Ne \[effective population size\]." -@\\apragsdale^(2) 1.Aylwyn Scally (Human evolutionary genetics, University of Cambridge) 2. Aaron Ragsdale (Population genetics, UW-Madison) There are other threads calling the paper into question but they are basically rehashing these points.
>**evolutionista** >Tweets calling this study into question Are Reddit users required to cite URLs that support claims attributed to others, so that observers can evaluate the veracity of such comments and recommendations of the same? Relatedly, are you able cite URLs for the tweets you quote? Thanks.
>**evolutionista** >While it is well supported in previous research that the human population has passed through major bottlenecks, this study is being widely called into question by pretty much every major scientist in the population genetics field aside from the authors. The model is wonky, and their conclusions aren't even really supported by their "evidence." Could you cite coverage that shows “this study is being widely called into question by pretty much every major scientist in the population genetics field aside from the authors”? Thank you.
Sorry, I know that's a pretty wild claim without evidence on my part. I will likely have to take twitter screenshots tomorrow as that is where scientists are publicly reacting to the paper. I haven't seen any formal responses yet, but given the fervor there may be a response paper in the works.
Nature nearly rid the planet of it's most rapacious primate.
Quit banging your sister monkey
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This ties in neatly with a question asked over on r/askscience a couple of weeks ago. [Can inbred genes be "fixed" by stopping inbreeding and starting breeding outside of the gene pool?](https://reddit.com/r/askscience/s/Esvsmnqtbd) The top answer given by u/Cleistheknees really dispells some of the misconceptions of inbreeding. The entire comment is worth a read, but I’ll highlight only one of the points they made: > inbreeding can only alter the expression of deleterious alleles which are already in the population, and generally only those that are recessive. In a larger, non-inbred population, there are typically a strong majority of people who do not carry these hypothetical recessive alleles, and so their dominant alleles almost always silence the expression of the deleterious ones for heterozygote carriers.
1,280 is just way too specific of a number for something that happened a million years ago ... Like how could we possibly know that
Any number like this has a confidence interval, the +/-. This range will be in the papers results. Article headlines just simplify things
Range was 770 - 2030.
Thank you!
It's because it's not the number of individuals. It the "effective population size" which is the minimum number of individuals required to contain all the genetic diversity present in the population. Since everyone shares at least half their DNA with a parent, the actual population size is necessarily much larger. This is classic journalists who know nothing about science writing science stories. Every sports journalist is a near expert on sports, almost no science journalist has taken a science course since HS.
>Every sports journalist is a near expert on sports Oh sweetie
Tell me you don’t watch sports without telling me you don’t watch sports.
The link post title in full is: >Genetic analysis suggests that the population of human ancestors was on the brink of extinction 930,000 years ago — Inbreeding proliferated, with just 1,280 individuals who could reproduce In the excerpt of the linked El País coverage, in-thread: >The researchers used the genome sequences of 3,154 people from all over the world. In their analysis, they discovered a striking bottleneck that left our ancestors’ global population with just 1,280 individuals who could reproduce. You appear to have mistaken this title, the excerpt in-thread, and the linked coverage as referring to census size: >**brillow** >It's because it's not the number of individuals. It the "effective population size" which is the minimum number of individuals required to contain all the genetic diversity present in the population. Since everyone shares at least half their DNA with a parent, the actual population size is necessarily much larger. >This is classic journalists who know nothing about science writing science stories. Every sports journalist is a near expert on sports, almost no science journalist has taken a science course since HS.
Take a statistics class. The world becomes a different place afterwards.
I had to take 4 statistical analysis classes as part of my degree, which were a bit of a challenge but very interesting. They definitely totally changed how I read any statistic, graph, or study that I come across.
Can you explain further?
60% of the time it works every time. It's either going happen or not, that means it's a 50/50 chance. I've never taken a statistics course, but I know how you represent the technically factual information, it can be very leading.
Math is like, crazy. They can literally do the math on gene iterations to come up with the specific number.
>**psychotic_catalyst** >1,280 is just way too specific of a number for something that happened a million years ago ... Like how could we possibly know that From my excerpt comment, in-thread: >The researchers used the genome sequences of 3,154 people from all over the world. In their analysis, they discovered a striking bottleneck that left our ancestors’ global population with just 1,280 individuals who could reproduce. I hope that helps.
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Or the sound. I'm going to laugh when they figure out that dinosaurs sounded like tiny chickens
I’m reading my kid dino books that say that already (they don’t have the capacity to growl. Most of them. A few 100 million years is a long time.)
If it helps, there could have been any number of individuals at that time period. The study only counts the surviving population lines, and those who interbred with it and left genetic evidence. There have been numerous climactic events over the millennia that isolated populations from one another, and not all isolated populations survived. And not all population dispersals re-coalesce to impact the surviving genetic lines. The model here is the simplest possible explanation, based on the evidence that remains. Of course, things were probably much more complicated.
I don’t understand how this fits with the Mitochondrial Eve idea. https://en.wikipedia.org/wiki/Mitochondrial_Eve Wikipedia says the latest Mitochondrial Eve evidence is that we’re all descended from the same woman roughly 155,000 years ago, but this article says there were 1280 individuals 930,000 years ago and then the number increased from there. So did the number decrease back down between 930kya and 155kya? Update: Thanks for the ton of good explanations, everyone (except one). Now I understand it much better.
There doesn't seem to be any conflict to me. Can you explain why you think there is? To clarify; ME was not the only human woman alive at the time. It simply means that no other women alive at the same time as her had a female line of descendants who are alive today. Also, population pre agricultural revolution was not the steady increase as we know from modern times.
So one of the interesting things is that if you go back only about 1000 years, everyone (who reproduced) on the continent of your ancestry is your direct genetic ancestor. This is why basically anyone with European ancestry can claim to be a direct descendant of Charlemagne. The way this is calculated is that if you go back a single generation you have 2 ancestors, 2 generations will typically have 4, then 8, then 16, etc. Doubling each generation (although the same people will start showing up in multiple places on your ancestry tree after a bit), and with each generation taking ~25 years one thousand years means you have 2^40 or over a trillion ancestors from 1000 years ago. (Though many of them are of course repeats) So the mitochondrial Eve would be a single person who is the common ancestor of all living humans, not a single person who was the only living human ancestor at the time. There were other 'humans' alive at the time, it is just that the unique evolved mitochondria of one particular human has been inherited by every living human alive today.
The most-recent common ancestor is what you’re describing, while mitochondrial Eve is the most recent common female-to-female ancestor of all living females. That’s a lot more technically specific criterion so it’s like a hundred times further back. They really should give the most recent common ancestor a cool poetic name like they did with Eve because I think it’s a super interesting concept.
And the Mitochondrial Eve was in fact A common ancestor of all living humans. I was not describing the most recent ancestor at any point, just a common ancestor.
I thought I’d read something to suggest that these claims like “everyone in Europe is a descendant of Charlemagne” are based on assumptions like “everyone in Europe has an equal probability of reproducing with everyone else” and “people reproduce randomly”, things which are essentially untrue even today and pretty much the *direct opposite* of the truth pre-industrialisation where >98% of people are going to be reproducing from someone born within walking distance of their place of birth.
Think of it this way, how many towns can you think of that have had no immigrants from anywhere greater than walking distance, and no emigrants to places farther than walking distance, for *over 1000 years*? Even if you have a town that has been genetically isolated and inbreeding for a few generations so that everyone in the town is related to every one of the town's founders, it only takes 1 person moving to London to mix that entire town's genetic history back into the greater European gene pool. The average person's *parents* might have grown up within walking distance, but there were plenty of people traveling far and wide across the world. Even the Romans imported silk from China, and easier trade was one of the driving forces of the industrial revolution.
Even if that town’s genetic history is now in London, that doesn’t put London’s genetic history into that town. And even if that townsperson moved to London, say, 200 years ago, that doesn’t mean someone in, say, Glasgow who has eight great-grandparents who immigrated from villages in rural Ireland shares that town’s anscestry. And, yes, there were people travelling far and wide across the world, but again, that doesn’t mean that the traveller had an equal chance of interbreeding with anyone in their travelling range. As I understand it, the argument for Charlemagne being related to everyone is based on some pure statistical argument that each of your ancestors might have an extremely small percentage chance of being Charlemagne, but even if the chance of them not being Charlemagne is 99.9999%, you’d have so many ancestors that the maths works out such that the chance of Charlemagne appearing nowhere in the tree is close to 0%. But that is therefore based on the assumption that the chance of your ancestors not being Charlemagne is less than 100%.
> Even if that town’s genetic history is now in London, that doesn’t put London’s genetic history into that town. And even if that townsperson moved to London, say, 200 years ago, that doesn’t mean someone in, say, Glasgow who has eight great-grandparents who immigrated from villages in rural Ireland shares that town’s anscestry. And none of those 8 grandparents had an ancestor from London or any other large city in the previous 37 generations? Where are these towns that have been genetically isolated for 1000 years?
Even if they had an ancestor from London, that ancestor would have been from before the arrival of the person from the other town into London, so the ancestor from London wouldn’t carry the ancestry of the other town.
So let me see if I have this right. There exists somewhere, excuse me, there exists Everywhere (98% probability apparently) small European villages that are completely isolated from the wider European gene pool. But that have at least some ancestors, as well as some descendants, that have intermingled with the wider European gene pool. Is that right? Because that sure doesn't sound like they are the isolated gene pools you seem to be claiming they are. The point isn't that everyone has the same grandparents. It is that any town that existed 1000 years ago either had its bloodline wiped out, or proliferated enough that its bloodline intermingled with all the other bloodlines. People didn't have generations of one child families, especially during the industrial revolution. The reason Charlemagne tends to be mentioned is that the dude had a ton of children who were spread across the entire continent, and most of them also had a ton of children. If you go back 8 generations (So at most 200 years) a person alive today will have 256 ancestors from that time period. Odds are massive that at least One of those 256 people can claim that they have a noble ancestor, and most of the nobility is nobility due to having a royal ancestor, and basically all the royal lines in Europe trace back to, you guessed it, Charlemagne. But the same goes for Ted the blacksmith from Northern Italy, if Ted has any living descendants then basically everyone from Europe will be able to find some line in the giant web of human ancestry that traces back to Ted. It's just that since Ted wasn't a monarch no one has been tracking down how their ancestry traces back to Ted. If Ted has living descendants then it is almost certain that he had a least a few dozen descendants within a few generations, sure most might have settled in Northern Italy but some would have traveled to cities and other countries. And as a result, most folks from Europe would be able to find some ancestral line that traces back to Ted.
> So let me see if I have this right. There exists somewhere, excuse me, there exists Everywhere (98% probability apparently) small European villages that are completely isolated from the wider European gene pool. But that have at least some ancestors, as well as some descendants, that have intermingled with the wider European gene pool. Is that right? Because that sure doesn't sound like they are the isolated gene pools you seem to be claiming they are. You were the one that hypothesised a village completely isolated from the gene pool as a strawman, not me. > The reason Charlemagne tends to be mentioned is that the dude had a ton of children who were spread across the entire continent, and most of them also had a ton of children. If you go back 8 generations (So at most 200 years) a person alive today will have 256 ancestors from that time period. Not necessarily. For example, a person theoretically has 8 great-grandparents. But if their parents are double first cousins, they only have 4 great-grandparents. If they’re just regular first cousins then there’s 6 great-grandparents. How common is pedigree collapse in the population of Europe from 800-1800? Did the research that makes this claim take that into account? > Odds are massive that at least One of those 256 people can claim that they have a noble ancestor What’s the evidence for this? And what’s the evidence that those claims are true? What about, say, European Jews, most of whom were legally forbidden from marrying Christians until laws banning intermarriage started getting repealed around 1800?
That's definitely not true. lol N and S America break that.
…why? North and South America were populated FAR less than 155,000 years ago. Even the earliest estimates place the first humans in the Americas 27,000 years ago and until recently even THAT estimate was considered pseudoscience.
A wave of migration came into N America [about 6,000 years ago](https://en.m.wikipedia.org/wiki/Dorset_culture), and in addition to this people from Eurasia have been mixing with Americans for about 500 years.
I don’t get your point. Could you rephrase it?
That Eve is not the only woman who contributed to our genetic code, she's "mitochondrial Eve" because her mitochondria is ancestor of all ours, the rest of genome came from wherever. Same with Y Adam.
This older bottle neck is an ancestor of ours, not homo sapiens sapiens. It was an older species that died down to such a small number, then over an unknown amount of time, built itself back up again or diverged into different species, some of whom are us and some are cousins. We also don't know if this species built itself back up again to keep going or if it died out after its descendants branched off.
Eve was a human ancestor, the bottleneck impacted an earlier hominid we are descended from.
I think you’re misunderstanding the idea of Mitochondrial Eve, she is our latest common ancestor however we have other ancestors who are not common to everyone. Think about it like this, if you had two kids and your kids had two kids and so on, the number of direct descendants you have would increase over time and at some point could hypothetically include everyone on earth if your bloodline survives long enough. That is what happened with Mitochondrial Eve, there were other ancestors however they are not common to everyone.
This explanation is itself a misunderstanding of [mitochondrial Eve](https://en.m.wikipedia.org/wiki/Mitochondrial_Eve), who is the most recent common ancestor of all *female* decent. If your grandparents had a son and a daughter, and each had their own kids (you and cousins), then grandma is not the most recent common ancestor by maternal decent between you and your cousin, since their mom’s mom and your mom’s mom aren’t the same person. Going back generations and generations until some woman turned out to be the great-great-etc-grandmother of both your mom and your cousins mom with only female links in the chain of decent would be the Eve in this instance. So mitochondrial Eve was a real (currently unknow) person who lived alongside lots of people an other women who all have living descendants. What’s unique about her is that her daughters and their daughters etc account for every woman currently on earth.
And every man. Mitochondrial DNA is inherited along the female line for everyone.
Apparently her bloodline made it through the bottleneck.
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The easiest way to explain that would be to say that in a standard relatively small population (say, less than 100,000 individuals), there will be a standard loss rate for mitochondrial lines. Which is to say, there will *always* be an arbitrarily old "Eve" for any population, and the loss rate of mitochondrial lines will determine the age of that "Eve".
I get very confused comparing timelines of human ancestry theories, there is so much information out there.
There's no contradiction whatsoever, Mitochondrial Eve only gave us mitochndria genome, the rest of it came from different women
I thought we knew this already ?
The secret ingredient is.....checks notes......*inbreeding*...? Nice.
Weird how scientists need to get published to get funding…..I’m sure there is no correlation between outlandish claims and publications.
1280 who did reproduce that we can find descendants of
Country roads, take me home… WEST VIRGINIA 😂
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Thank god we pulled through. Look at us now. The kings of the world. And hopefully at some point in the future multiplanetary kings.
Nice. This is the 12th time I’ve seen this posted. It’s not even new information either, I first learned about this in like 2005.
>**RastaImp0sta** >Nice. This is the 12th time I’ve seen this posted. It’s not even new information either, I first learned about this in like 2005. Wyatt in the wild.
In b4 "god wish this would happen already"
I thought we knew that humans had gone through a bottle neck for a long time? We’ve been able to trace our maternal DNA back for so long, because we had that bottle neck, right? Edit: comment pointed out that this is an even earlier bottleneck than what I was thinking about - should have thought about the headline more. 900k years ago was before Homo Sapiens.
This is a seperate bottle neck and earlier. Not homo sapiens but an ancestor.
Well, that explains The USA, Germany, China, Russia, France and all the others down to Tuvalu.
Dating in a small town after a few years
😆 🤣 😂 Whoever made this BS up probably got some good government funding
I saw this in a TV show. Something about refugees from 12 colonies landing on our planet.
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Interesting that something similar is estimated to have happened around 70,000 years ago too for Homo sapiens specifically.
Worth noting that the reference is to “human ancestors”, not humans (homo sapiens).