>"The huge gap between those ages could change our understanding about how humans spread across the world. If the ancestors of todayâs non-Africans didnât sweep across other continents until 47,000 years ago, then those older sites must have been occupied by earlier waves of humans who died off without passing down their DNA to the people now living in places like China and Australia."
But at the end gets a bit more balanced
>"He Yu, a paleogeneticist at Peking University in Beijing who was not involved in either study, said that the mystery wouldnât be solved until scientists find DNA in some of the ancient Asian fossils.
âWe still need early modern human genomes from Asia to really talk about Asia stories,â Dr. Yu said."
It doesnât seem like an outlandish claim that many waves of humans tried and failed to colonize the world, until one succeeded. I would find it harder to believe that the first to leave Africa got it right first time.
One question raised by a researcher in the article:
Dr. Skoglund also said it would be strange for non-African ancestors to have arisen about 47,000 years ago while modern humans in Asia and Australia dated back 100,000 years. The sites in question could have been incorrectly dated, he said, or people could have reached Asia and Australia that long ago, only to die out.
Doesn't mesh well with genetic studies from Australia that show a long history of relatively stable regionalism within Australia (with some still unresolved mixing from Denisovan ancestors.
The actual results in papers like these (both the paper in question and the ones you refer to) are typically of the form: "We sequenced these genomes. Then we took the noisy data, made a lot of assumptions, and applied statistical magic to estimate that the populations split approximately X generations ago. We interpret that as Y years ago." Everything beyond that is interpretation, not the result.
Such results are inherently noisy and subject to assumptions. The further back in history you go, the less accurate and reliable the results will be. Ancient DNA comes with its own issues and assumptions, but it helps with the accuracy of the results. Instead of trying to infer something that happened thousands of generations ago, you may now be only hundreds or even tens of generations from the split.
The clearest way forward would be sequencing Aboriginal Australian DNA from tens of thousands of years ago. Then you could get a more accurate estimate for the split between that population and other sequenced ancient populations.
my own theory. Depending on cyclical geography limitations, humans have been forever moving out of Africa sporadically, going way back to Neanderthals and possibly even before. It wasn't just one wave, it was multiple waves from time to time.
The people that ended up in Australia were some of the earliest anatomically modern humans that successfully made the trip out and for some reason or the other were not really able to colonize Europe/Asia and kept venturing south until they ended up in Australia
Other later waves probably made it to the middle east and went back. Some made it a bit into Europe and some of asia. But it wasn't until relatively recent times, that we got waves that finally got a foothold in Europe/Asia and eventually outlasted other homo species that had dominated those areas for a 100,000 years.
I am not an anthropologist. I can't prove anything I wrote. I am just using my own common sense and the evidence that has so far been published.
I doubt it's correct to assume groups of humans in Africa one day decided to 'colonize' another place and walked thousands of kilometers to settle down elsewhere. It's probably more like a slow expansion (and reduction) of the settled area, no?
Both processes could coexist, right? I could see myself waking up one day and saying "what's the farthest we can get to? maybe there are amazing things at the end of the journey"
Iâm not 100% clear on what the two processes are. In particular, early humans already were pretty mobile. So theyâd be going from place to place, hunting as they go. Maybe following some migratory animals. If you got wanderlust, I guess youâd only make it a couple days before you ran out of food, so maybe some dozens of miles, and then you are back to doing typical human stuff, right?
I don't think a group of people living somewhere for thousands of years would be "getting it wrong." You're embedding an assumption that evolution has been working toward an end goal of getting humans to spread globally, which isn't how evolution works.
That's distinct from making a claim, an assertion with supporting evidence.
To make a claim, we would want evidence, and the evidence here would be a genetic isolation (lack of chronological overlap, synonymous with lack of interbreeding) of ancient Asian humans from ancient African humans. This requires sequencing a lot of ancient Asian DNA, which seems not to have happened yet. We barely have a cohesive evidence supported grasp of Neanderthal interactions in Europe, but are gradually updating to support more and more absorption by interbreeding.
I think the claim is that earlier founders did colonize the world before the final group left and also colonized the world. Land bridges disappeared as the last ice age came to a close, making later attempts more difficult
I think they just walked to other places as and when the climate changed. Some adapted and stayed, others moved the greener pastures. This slow and climate-driven process can hardly be described as colonization.
The view of the chinese researcher is in line with the Multiregional origin hypothesis of modern humans, where asian humans may partially come from asia. So his reply is not surprising.
Instead, the article follow the Out of Africa origin, and therefore did not explain the old chineses and autralian remains. The article try to explain this by saying than it's because this lines where extincts or than the dates are wrong, but this explanations are not very convincing.
Whatâs the most significant difference between the theories? The Wikipedia article says:
> âThe primary competing scientific hypothesis is currently recent African origin of modern humans, which proposes that modern humans arose as a new species in Africa around 100-200,000 years ago, moving out of Africa around 50-60,000 years ago to replace existing human species such as Homo erectus and the Neanderthals without interbreeding.[5][6][7][8] This differs from the multiregional hypothesis in that the multiregional model predicts interbreeding with preexisting local human populations in any such migration.â
But it is a somewhat weird quote in the Wikipedia article. Theyâve got the whole thing in quotes with multiple citations (so it isnât clear which citation the quote comes from), it isnât attributed to anybody in particular, and it doesnât seem to be a very accurate description of what I though the consensus was, at least. (It is widely believed that humans interbred with other hominids, right?)
Am I missing something? Surely Europe is the same continent as Asia. Why wouldn't people just walk over? It seems reasonable to assume that if evidence exists on one side of the continent that it'd imply existence on the other side, too. If anything you'd need a theory why they failed to spread to formulate interesting discussion!
> Some 45,000 years ago, a tiny group of people â fewer than 1,000, all told â wandered the icy northern fringes of Europe.
Is it not possible that:
Some 45,000 years ago, a tiny group of people â fewer than 1,000, all told â wandered from sunny Australia into China, eventually reaching Africa and Europe?
Africa is a static large site of habitation where the disappearance of 99% of evidence would still leave easily findable evidence. In GPâs scenario the habitation would be transient. Not really comparable.
I mean the fictional assumption is that it was a single group that wandered thousands of miles across continents; it was many generations that would settle somewhere, with subsequent generations migrating and spreading slowly, leaving behind traces like gravesites and settlements and the like; combine that with accurate dating and you can in fact tell the direction of travel.
No. The genomes tell a pretty clear story. Should your hypothesis be correct, you would find haplogroups in the 45kya group descended from the 60kya austronesian group - but you do not. Rather, you find a most recent common ancestor before the 60kya group left Africa. As to why Africa - this is where ancestral hominids and the earliest known sapiens specimens have been found. While we have found cousins elsewhere, the evidence all points towards sapiens having emerged in Africa and spread elsewhere in successive waves.
When the hypothesis first appeared it was somewhat shocking to science, as the leading theory was some sort of parallel emergence of the races - but this was not grounded in the evidence being found in Africa at the time, and genetic evidence has since cemented this not as hypothesis, but well-established theory.
The current "Out of Africa" is really not the same as what you might have learned 2-3 decades ago, despite the branding. David Reich is probably the leading researcher in this field and his description of our best guesses is highly nuanced and open to new data.
> Would any evidence that contradicts the 'Out-of-Africa' dogma even get considered by Western scientists?
An easy example is that neanderthals, denisovans, h erectus, etc contribute via admixture to Homo Sapien Sapiens and well predate "out of africa" dates by hundreds of thousands of years. It's not a hard stretch to presume that other yet-unnamed branches of modern humans left earlier and admixed the same as the other named groups.
I don't think anyone is proposing an extant group of humans that don't have relatively recent roots in africa, though.
Out of Africa was fought by the majority of Western scientists during the early 20th century because of their pro-European biases. The reason its accepted is because the preponderance of evidence supports it.
there were also a lot of sociocultural changes coming out of the 60s/70s that changed the scientific conclusions we drew.
it used to be that we saw changes in ancient pottery and language and assumed that previous people had been replaced by new people with different techniques. then, in the 60s/70s it became popular that these changes didnât mark population replacement but were more cultural spread and shift.
then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.
there are lots of theories from the mid-20th that havenât yet had their âgenetics in the 90sâ moment.
> then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.
I think the current consensus is a fusion of the two stances, particularly as some of the changes have appeared to be too rapid to reflect population displacement, and genetics clearly indicate genetic admixture with varying distinguishing characteristics relevant to the region and timeperiod as opposed to straight displacement.
Unsatisfying, I know, but basically any firm position on either side has equally firm arguments against it.
I had a recent discussion about this, will try to pull up the sources, but my understanding is displacement is the majoritarian current and cultural shift with same population very much a secondary that only applies in a minority of the cases
a lot of these admixture events show near total displacement of the y chromosome also
I'm not disbelieving your source entirely, but it seems a little ridiculous to assume population displacement across all pre-history. Particularly when modern populations are so genetically diverse.
No doubt those biased Europeans felt their theory had the preponderance of evidence behind it. Funny how often the settled science is like that until the incumbent scientists die off rather than because better evidence was considered and adopted by science.
This appears to be a research and not part of a dogma and Africa is not part of the Western World. What your comment implies in terms of Science and Conspiracy is so esoteric that you need to level up the credibility of your sources of information.
Makes a huge claim at the start.
>"The huge gap between those ages could change our understanding about how humans spread across the world. If the ancestors of todayâs non-Africans didnât sweep across other continents until 47,000 years ago, then those older sites must have been occupied by earlier waves of humans who died off without passing down their DNA to the people now living in places like China and Australia."
But at the end gets a bit more balanced
>"He Yu, a paleogeneticist at Peking University in Beijing who was not involved in either study, said that the mystery wouldnât be solved until scientists find DNA in some of the ancient Asian fossils. âWe still need early modern human genomes from Asia to really talk about Asia stories,â Dr. Yu said."
This puzzle is still missing key elements.
It doesnât seem like an outlandish claim that many waves of humans tried and failed to colonize the world, until one succeeded. I would find it harder to believe that the first to leave Africa got it right first time.
One question raised by a researcher in the article:
Doesn't mesh well with genetic studies from Australia that show a long history of relatively stable regionalism within Australia (with some still unresolved mixing from Denisovan ancestors.see:
(2016) https://www.abc.net.au/news/science/2016-09-22/world-first-s...
(2017) https://www.nature.com/articles/nature21416
etc.
The actual results in papers like these (both the paper in question and the ones you refer to) are typically of the form: "We sequenced these genomes. Then we took the noisy data, made a lot of assumptions, and applied statistical magic to estimate that the populations split approximately X generations ago. We interpret that as Y years ago." Everything beyond that is interpretation, not the result.
Such results are inherently noisy and subject to assumptions. The further back in history you go, the less accurate and reliable the results will be. Ancient DNA comes with its own issues and assumptions, but it helps with the accuracy of the results. Instead of trying to infer something that happened thousands of generations ago, you may now be only hundreds or even tens of generations from the split.
The clearest way forward would be sequencing Aboriginal Australian DNA from tens of thousands of years ago. Then you could get a more accurate estimate for the split between that population and other sequenced ancient populations.
my own theory. Depending on cyclical geography limitations, humans have been forever moving out of Africa sporadically, going way back to Neanderthals and possibly even before. It wasn't just one wave, it was multiple waves from time to time.
The people that ended up in Australia were some of the earliest anatomically modern humans that successfully made the trip out and for some reason or the other were not really able to colonize Europe/Asia and kept venturing south until they ended up in Australia
Other later waves probably made it to the middle east and went back. Some made it a bit into Europe and some of asia. But it wasn't until relatively recent times, that we got waves that finally got a foothold in Europe/Asia and eventually outlasted other homo species that had dominated those areas for a 100,000 years.
I am not an anthropologist. I can't prove anything I wrote. I am just using my own common sense and the evidence that has so far been published.
I doubt it's correct to assume groups of humans in Africa one day decided to 'colonize' another place and walked thousands of kilometers to settle down elsewhere. It's probably more like a slow expansion (and reduction) of the settled area, no?
Both processes could coexist, right? I could see myself waking up one day and saying "what's the farthest we can get to? maybe there are amazing things at the end of the journey"
Iâm not 100% clear on what the two processes are. In particular, early humans already were pretty mobile. So theyâd be going from place to place, hunting as they go. Maybe following some migratory animals. If you got wanderlust, I guess youâd only make it a couple days before you ran out of food, so maybe some dozens of miles, and then you are back to doing typical human stuff, right?
I don't think a group of people living somewhere for thousands of years would be "getting it wrong." You're embedding an assumption that evolution has been working toward an end goal of getting humans to spread globally, which isn't how evolution works.
And their failure doesn't mean they're completely absent from our genome.
It doesn't seem like an outlandish possibility.
That's distinct from making a claim, an assertion with supporting evidence.
To make a claim, we would want evidence, and the evidence here would be a genetic isolation (lack of chronological overlap, synonymous with lack of interbreeding) of ancient Asian humans from ancient African humans. This requires sequencing a lot of ancient Asian DNA, which seems not to have happened yet. We barely have a cohesive evidence supported grasp of Neanderthal interactions in Europe, but are gradually updating to support more and more absorption by interbreeding.
I think the claim is that earlier founders did colonize the world before the final group left and also colonized the world. Land bridges disappeared as the last ice age came to a close, making later attempts more difficult
I think they just walked to other places as and when the climate changed. Some adapted and stayed, others moved the greener pastures. This slow and climate-driven process can hardly be described as colonization.
The view of the chinese researcher is in line with the Multiregional origin hypothesis of modern humans, where asian humans may partially come from asia. So his reply is not surprising.
https://en.wikipedia.org/wiki/Multiregional_origin_of_modern...
Instead, the article follow the Out of Africa origin, and therefore did not explain the old chineses and autralian remains. The article try to explain this by saying than it's because this lines where extincts or than the dates are wrong, but this explanations are not very convincing.
Whatâs the most significant difference between the theories? The Wikipedia article says:
> âThe primary competing scientific hypothesis is currently recent African origin of modern humans, which proposes that modern humans arose as a new species in Africa around 100-200,000 years ago, moving out of Africa around 50-60,000 years ago to replace existing human species such as Homo erectus and the Neanderthals without interbreeding.[5][6][7][8] This differs from the multiregional hypothesis in that the multiregional model predicts interbreeding with preexisting local human populations in any such migration.â
But it is a somewhat weird quote in the Wikipedia article. Theyâve got the whole thing in quotes with multiple citations (so it isnât clear which citation the quote comes from), it isnât attributed to anybody in particular, and it doesnât seem to be a very accurate description of what I though the consensus was, at least. (It is widely believed that humans interbred with other hominids, right?)
Am I missing something? Surely Europe is the same continent as Asia. Why wouldn't people just walk over? It seems reasonable to assume that if evidence exists on one side of the continent that it'd imply existence on the other side, too. If anything you'd need a theory why they failed to spread to formulate interesting discussion!
https://archive.ph/WLcdD
Thank you!
This doesn't account for shrinkage in the pool
It's amazing how out of date this conception is with the actual research.
I guess it's to be expected that pop-sci is 10-15 years behindâŚ
Such fictional assumptions...
> Some 45,000 years ago, a tiny group of people â fewer than 1,000, all told â wandered the icy northern fringes of Europe.
Is it not possible that:
Some 45,000 years ago, a tiny group of people â fewer than 1,000, all told â wandered from sunny Australia into China, eventually reaching Africa and Europe?
It is impossible to tell the direction of travel.
Is it not possible that:
You'd be able to look for and find some evidence of their ancestors in Australia and you don't. But there's plenty of it in Africa.
Africa is a static large site of habitation where the disappearance of 99% of evidence would still leave easily findable evidence. In GPâs scenario the habitation would be transient. Not really comparable.
That assumes all evidence is equally easy to find and has been equally searched for.
It is not really up for debate. Haplogroups provide direct lineage and evidence for migration.
I mean the fictional assumption is that it was a single group that wandered thousands of miles across continents; it was many generations that would settle somewhere, with subsequent generations migrating and spreading slowly, leaving behind traces like gravesites and settlements and the like; combine that with accurate dating and you can in fact tell the direction of travel.
No. The genomes tell a pretty clear story. Should your hypothesis be correct, you would find haplogroups in the 45kya group descended from the 60kya austronesian group - but you do not. Rather, you find a most recent common ancestor before the 60kya group left Africa. As to why Africa - this is where ancestral hominids and the earliest known sapiens specimens have been found. While we have found cousins elsewhere, the evidence all points towards sapiens having emerged in Africa and spread elsewhere in successive waves.
When the hypothesis first appeared it was somewhat shocking to science, as the leading theory was some sort of parallel emergence of the races - but this was not grounded in the evidence being found in Africa at the time, and genetic evidence has since cemented this not as hypothesis, but well-established theory.
Would any evidence that contradicts the 'Out-of-Africa' dogma even get considered by Western scientists?
The current "Out of Africa" is really not the same as what you might have learned 2-3 decades ago, despite the branding. David Reich is probably the leading researcher in this field and his description of our best guesses is highly nuanced and open to new data.
https://www.youtube.com/watch?v=Uj6skZIxPuI
https://www.razibkhan.com/p/out-of-africas-midlife-crisis
> Would any evidence that contradicts the 'Out-of-Africa' dogma even get considered by Western scientists?
An easy example is that neanderthals, denisovans, h erectus, etc contribute via admixture to Homo Sapien Sapiens and well predate "out of africa" dates by hundreds of thousands of years. It's not a hard stretch to presume that other yet-unnamed branches of modern humans left earlier and admixed the same as the other named groups.
I don't think anyone is proposing an extant group of humans that don't have relatively recent roots in africa, though.
Out of Africa was fought by the majority of Western scientists during the early 20th century because of their pro-European biases. The reason its accepted is because the preponderance of evidence supports it.
there were also a lot of sociocultural changes coming out of the 60s/70s that changed the scientific conclusions we drew.
it used to be that we saw changes in ancient pottery and language and assumed that previous people had been replaced by new people with different techniques. then, in the 60s/70s it became popular that these changes didnât mark population replacement but were more cultural spread and shift.
then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.
there are lots of theories from the mid-20th that havenât yet had their âgenetics in the 90sâ moment.
> then genetics came around in the 90s and obliterated the cultural hypothesis and showed that in most of these cases it was largely population replacement.
I think the current consensus is a fusion of the two stances, particularly as some of the changes have appeared to be too rapid to reflect population displacement, and genetics clearly indicate genetic admixture with varying distinguishing characteristics relevant to the region and timeperiod as opposed to straight displacement.
Unsatisfying, I know, but basically any firm position on either side has equally firm arguments against it.
I had a recent discussion about this, will try to pull up the sources, but my understanding is displacement is the majoritarian current and cultural shift with same population very much a secondary that only applies in a minority of the cases
a lot of these admixture events show near total displacement of the y chromosome also
I'm not disbelieving your source entirely, but it seems a little ridiculous to assume population displacement across all pre-history. Particularly when modern populations are so genetically diverse.
No doubt those biased Europeans felt their theory had the preponderance of evidence behind it. Funny how often the settled science is like that until the incumbent scientists die off rather than because better evidence was considered and adopted by science.
Sure!
If you've encountered some then please share!
yes, see david reich
This appears to be a research and not part of a dogma and Africa is not part of the Western World. What your comment implies in terms of Science and Conspiracy is so esoteric that you need to level up the credibility of your sources of information.
> from European fossils dating back 45,000 years
It is racist BS.
There were modern humans in Australia 60k years ago. Europe was also colonized way before that date. And some modern humans never left Africa.
Yes.