Migration out of Africa may have been driven by first glaciation of Pleistocene(phys.org)
phys.org
Migration out of Africa may have been driven by first glaciation of Pleistocene
https://phys.org/news/2024-03-migration-hominins-africa-driven-major.html
60 comments
> while Denisovans left at the same time into Asia ending up concentrated in Serbia.
You probably meant to write Siberia.
You probably meant to write Siberia.
I did! Thank you.
"Neanderthals left Africa 500,000 years later into Europe while Denisovans left at the same time"
For most of the past 25 years there was a theory that Neanderthals and Denisovans were descended from Homo Heidelbergensis, in which case Neanderthals and Denisovans probably evolved in Europe or the Middle East. The oldest known Homo Heidelbergensis is maybe 1 millions years old and most of the early Homo Heidelbergensis were found in Europe, so it is assumed that Homo Heidelbergensis evolved in Europe.
Recently, many have argued that Neanderthals and Denisovans were not descended from Homo Heidelbergensis, but instead from some other species of humans that has not yet been discovered. But it remains likely that Neanderthals and Denisovans evolved outside of Africa.
For most of the past 25 years there was a theory that Neanderthals and Denisovans were descended from Homo Heidelbergensis, in which case Neanderthals and Denisovans probably evolved in Europe or the Middle East. The oldest known Homo Heidelbergensis is maybe 1 millions years old and most of the early Homo Heidelbergensis were found in Europe, so it is assumed that Homo Heidelbergensis evolved in Europe.
Recently, many have argued that Neanderthals and Denisovans were not descended from Homo Heidelbergensis, but instead from some other species of humans that has not yet been discovered. But it remains likely that Neanderthals and Denisovans evolved outside of Africa.
> They also left Africa in multiple waves with 5 main ones spreading out across the globe.
Where can I learn more about these 5 waves?
Where can I learn more about these 5 waves?
I always liked this map that helped convey the possible pathways that spread humans from the main wave: https://en.wikipedia.org/wiki/File:World_map_of_prehistoric_...
One useful page that references the image:
https://en.wikibooks.org/wiki/Ancient_History/Human_Evolutio...
https://en.wikibooks.org/wiki/Ancient_History/Human_Evolutio...
Such a wonderful projection.
The number of waves and the granulation of waves isn't set in stone as such; there's a pretty decent broad view from afar regarding early human, and a great deal of finer detail still up for debate.
Reading through
https://en.wikipedia.org/wiki/Early_human_migrations
top to bottom will give a good enough first overview and an idea of where uncertainly lies and references to chase for further debate.
Eg: Currently there's some hot debate on whether parts of the "coastal migration" to Australasia took place over inland routes within South East Asia - that's a matter of old coast lines at the time, inland cave shelters with datable bones, and a sparse game of chronological joind the estimated dots in space and time - it gets technical.
Reading through
https://en.wikipedia.org/wiki/Early_human_migrations
top to bottom will give a good enough first overview and an idea of where uncertainly lies and references to chase for further debate.
Eg: Currently there's some hot debate on whether parts of the "coastal migration" to Australasia took place over inland routes within South East Asia - that's a matter of old coast lines at the time, inland cave shelters with datable bones, and a sparse game of chronological joind the estimated dots in space and time - it gets technical.
Who We Are and How We Got Here by David Reich is I think a great book if you're interested in human migrations.
> Where can I learn more about these 5 waves?
You simply go back 2 million years and verify it yourself.
Alternatively, read it on wikipedia.
You simply go back 2 million years and verify it yourself.
Alternatively, read it on wikipedia.
I think my favorite strange factoid of human migration, is that Madagascar was (majority) settled from Borneo, not from Africa.
https://theconversation.com/how-the-banjar-people-of-borneo-...
https://en.wikipedia.org/wiki/History_of_Madagascar
includes the nice map:
https://en.wikipedia.org/wiki/History_of_Madagascar#/media/F...
https://theconversation.com/how-the-banjar-people-of-borneo-...
https://en.wikipedia.org/wiki/History_of_Madagascar
includes the nice map:
https://en.wikipedia.org/wiki/History_of_Madagascar#/media/F...
Another interesting way to headline this is, Madagascar was the last place on earth to be settled, despite being right next to the first
Apart from Antarctica - New Zealand seems to be the last large landmass to be settled in 1200 AD (see map linked above).
But even in NZ, there are some inconclusive claims of previous civilization. The gov has banned access and excavations to verify or refute the claims. One example:
https://www.ancient-origins.net/ancient-places-oceania/kaima...
But even in NZ, there are some inconclusive claims of previous civilization. The gov has banned access and excavations to verify or refute the claims. One example:
https://www.ancient-origins.net/ancient-places-oceania/kaima...
Kind of looks natural to me, and if there were a civilization that made one wall like this I'd expect a lot more walls like it. That said, it seems worth investigating. Why would the New Zealand government want it covered up?
Scientists have, in fact, investigated it [1] and concluded it is a natural feature. Reading up on ancient-origins.net seems to suggest that it lets a lot of pseudoscience and conspiracy theories (ancient aliens and so on) creep in alongside credible articles.
1. https://www.nzherald.co.nz/waikato-news/news/kaimanawa-wall-...
1. https://www.nzherald.co.nz/waikato-news/news/kaimanawa-wall-...
The NZ government has a vested interest in not examining the pre colonial past.
> Madagascar was the last place on earth to be settled
I believe that honor belongs to antarctica.
https://en.wikipedia.org/wiki/Colonization_of_Antarctica
I believe that honor belongs to antarctica.
https://en.wikipedia.org/wiki/Colonization_of_Antarctica
If temperatures dropped during the onset of the Pleistocene. Then why would humans have migrated away from Africa to Europe? It seems to me that in Europe it would be even more cold.
The article suggests that this may have in part been due to the falling sea levels. Europe extended much further to the North to the point that Great Britain was surrounded by land. The gap between Europe and Africa was also close enough to allow for much easier crossings.
Early humans were likely always somewhat migratory animals as there was no way to preserve food for longer periods - grain agriculture was what allowed for permanent settlements and bureaucracy (i.e. long-term planning and resource allocation). They may have tended to the local vegetation because they would likely return in the future but it seems obvious that they'd also be on the lookout for new places while keeping track of known good spots in the past - even elephants travel between distant "watering holes".
In other words: it wasn't the cold that was the problem, it was the availability of resources, i.e. food. If the accessible parts of Europe had sufficient food to make them attractive for foraging and hunting, humans would eventually make the crossing and decide to stay and eventually move further into the continent. Note that we're not talking about events that happened over human lifetimes - the North Sea didn't drain overnight.
Maybe a visual aid helps. Try to find Europe on this map. Hint: look for mountains that look like familiar coastlines: https://en.wikipedia.org/wiki/File:Global_sea_levels_during_...
Early humans were likely always somewhat migratory animals as there was no way to preserve food for longer periods - grain agriculture was what allowed for permanent settlements and bureaucracy (i.e. long-term planning and resource allocation). They may have tended to the local vegetation because they would likely return in the future but it seems obvious that they'd also be on the lookout for new places while keeping track of known good spots in the past - even elephants travel between distant "watering holes".
In other words: it wasn't the cold that was the problem, it was the availability of resources, i.e. food. If the accessible parts of Europe had sufficient food to make them attractive for foraging and hunting, humans would eventually make the crossing and decide to stay and eventually move further into the continent. Note that we're not talking about events that happened over human lifetimes - the North Sea didn't drain overnight.
Maybe a visual aid helps. Try to find Europe on this map. Hint: look for mountains that look like familiar coastlines: https://en.wikipedia.org/wiki/File:Global_sea_levels_during_...
No idea, wild guesses incoming...
Early humans (or proto humans) might not know that it was warmer in the south or colder in the north, across vast areas. Some days are colder than others, even if you stand still. Add to this the effect of changing seasons through a year, some years being colder than others anyway. You could migrate North slowly as Winter turned to Summer. Then camp for the winter and migrate back. And their migrations might have moved slightly further north year by year. They would have to track temperatures from winter to winter, without a calendar, thermometer, notebook, pen, map, compass and perhaps even an enquiring mind.
I don't think that humans decided to move to a colder place or even realised that their movement was taking them somewhere cooler.
Ultimately, they would have followed their food wherever it went. You might be better off asking why a caribou herd migrated further North. Who knows? Better grass? Less competition? Fewer predators? Lower sea level opening a path to new grassland?
Early humans (or proto humans) might not know that it was warmer in the south or colder in the north, across vast areas. Some days are colder than others, even if you stand still. Add to this the effect of changing seasons through a year, some years being colder than others anyway. You could migrate North slowly as Winter turned to Summer. Then camp for the winter and migrate back. And their migrations might have moved slightly further north year by year. They would have to track temperatures from winter to winter, without a calendar, thermometer, notebook, pen, map, compass and perhaps even an enquiring mind.
I don't think that humans decided to move to a colder place or even realised that their movement was taking them somewhere cooler.
Ultimately, they would have followed their food wherever it went. You might be better off asking why a caribou herd migrated further North. Who knows? Better grass? Less competition? Fewer predators? Lower sea level opening a path to new grassland?
If human populations expanded at a slow rate of 20 miles per 100 years, then from 1.1 million to 0.9 million years ago (200,000 years) they would have travelled 40,000 miles.
This is indeed migration, but not as we think of it today. Such migrations could have been blocked by oceans or high mountains, and were essentially like animal migrations.
This is indeed migration, but not as we think of it today. Such migrations could have been blocked by oceans or high mountains, and were essentially like animal migrations.
The notion that bad environment caused migration seems very dubious.
What causes migration is the ability to migrate: that is, that new areas have environments in which the organisms can survive and reproduce. Decline in habitability of previously occupied regions is neither necessary nor useful for this to happen.
What causes migration is the ability to migrate: that is, that new areas have environments in which the organisms can survive and reproduce. Decline in habitability of previously occupied regions is neither necessary nor useful for this to happen.
The assertion is not that (all) migration is caused by environmental changes.
The claim is that environmental changes can drive migration (causing it to start, or to accelerate migration already happening for other reasons).
Specifically that a particular wave of migration out of part of Africa was pushed along by glaciation 9,000 years ago.
This is not a dubious notion; it seems certain that either environment changes drove migration out of Doggerland or that humans in Doggerland drowned.
> Decline in habitability of previously occupied regions is
barely half the full picture; glaciation can open land bridges allowing increased access to new destinations which are more habitable.
The claim is that environmental changes can drive migration (causing it to start, or to accelerate migration already happening for other reasons).
Specifically that a particular wave of migration out of part of Africa was pushed along by glaciation 9,000 years ago.
This is not a dubious notion; it seems certain that either environment changes drove migration out of Doggerland or that humans in Doggerland drowned.
> Decline in habitability of previously occupied regions is
barely half the full picture; glaciation can open land bridges allowing increased access to new destinations which are more habitable.
I'm not disputing glaciation had an effect, it's just that a decline in habitability of where the hominids were living was not an effect that can be pointed to as a cause of migration. If anything, there should be more outmigration from highly habitable areas than from less habitable ones. That's because any area quickly fills up to the limit of its carrying capacity, and the highly habitable area will then have more inhabitants to diffuse out.
The assertion is that change in environmental conditions allowed for migration:
> a decline in habitability of where the hominids were living was not an effect that can be pointed to as a cause of migration.
and I can see no reason why you would make this claim.
They then pointed out that evidence in past research showed hominin habitation all across Eurasia started approximately 900,000 years ago, which coincides with the onset of the first Pleistocene ice age. As the ice age began, ocean levels would have dropped, allowing hominins an easier route from Africa.
Two recently published analyses make cases for severe bottlenecking of human populations occurring in the late Early Pleistocene, one case at about 0.9 Mya based on a genomic analysis of modern human populations and the low number of hominin sites of this age in Africa and the other at about 1.1 Mya based on an age inventory of sites of hominin presence in Eurasia.
We suggest that the best available data are consistent with the Galerian hypothesis expanded from Europe to Eurasia as a major migration pulse of fauna including hominins in the late Early Pleistocene as a consequence of the opening of land routes from Africa facilitated by a large sea level drop associated with the first major ice age of the Pleistocene and concurrent with widespread aridity across Africa that occurred during marine isotope stage 22 at ~0.9 Mya
> a decline in habitability of where the hominids were living was not an effect that can be pointed to as a cause of migration.
and I can see no reason why you would make this claim.
I have already explained the logic behind the claim.
The things you quote there do not justify a claim that reduction in habitability would cause migration. They do justify a claim that an increase in habitability of nearby areas could cause migration to those areas. The hominids cannot diffuse into an area in which they cannot survive as a population (or rather, they can, but they just die out, so the spread stops), but if the area became sufficiently more habitable then those diffusing in could then sustain a population there and act as a base for further diffusion.
The things you quote there do not justify a claim that reduction in habitability would cause migration. They do justify a claim that an increase in habitability of nearby areas could cause migration to those areas. The hominids cannot diffuse into an area in which they cannot survive as a population (or rather, they can, but they just die out, so the spread stops), but if the area became sufficiently more habitable then those diffusing in could then sustain a population there and act as a base for further diffusion.
I wonder which routes were opened by this. Gibraltar ? Tunisia -> Sicilly -> Italy ?
In any case the Levant was always an out.
In any case the Levant was always an out.
You might like this YT video about the refilling of the Med...
The MEGAFLOOD that brutally filled the Mediterranean in months
https://www.youtube.com/watch?v=_RSPgIcnRN0
The Med was created by long-term tectonic forces, which closed the sea at Gibraltar, about 7 million years ago. The whole thing dried out, leaving salt deposits on the lowest dusty plains (like Great Salt Lake, Dead Sea, Aral Sea today). Enough dust, dirt and seasonal river inflow, covered the salt in sedimentary layers.....
About 6 million years ago, Gibraltar was breached by rising sea levels, and flooded the Balearic (W. Med) basin, up to the line Italy-Sicily-Tunisia.
Very shortly afterwards (months < 2 years) the water breached the high ground immediately south of Sicily, creating the subsea Noto Canyon, and filling the eastern Med.
P.S. Interesting final comment - the Black Sea was probably not filled by a similar dramatic flood through the Bosphorus. Alluvial structures and fans in the Black Sea floor, show that it silted up from the north, and almost certainly overflowed the Bosphorus from the north, which is why the Bosphorus is relatively narrow - not the whole Med carving wide straits, but a freshwater trickle out from the silted Black Sea.
P.P.S. Also note this contradicts some imagined historical basis for the Gilgamesh and Biblical floods being in the Black Sea (in the direction of what is now called Mt. Ararat). Those tales are much more likely to refer to Mesopotamian floods of the Tigris or Euphrates, perhaps triggered by breaching of earthquake-induced rockslides that temporarily blocked one of the rivers. We can now date and locate a specific episode like this in ancient China 4,000 years ago:
https://www.nationalgeographic.com/science/article/china-yel...
The MEGAFLOOD that brutally filled the Mediterranean in months
https://www.youtube.com/watch?v=_RSPgIcnRN0
The Med was created by long-term tectonic forces, which closed the sea at Gibraltar, about 7 million years ago. The whole thing dried out, leaving salt deposits on the lowest dusty plains (like Great Salt Lake, Dead Sea, Aral Sea today). Enough dust, dirt and seasonal river inflow, covered the salt in sedimentary layers.....
About 6 million years ago, Gibraltar was breached by rising sea levels, and flooded the Balearic (W. Med) basin, up to the line Italy-Sicily-Tunisia.
Very shortly afterwards (months < 2 years) the water breached the high ground immediately south of Sicily, creating the subsea Noto Canyon, and filling the eastern Med.
P.S. Interesting final comment - the Black Sea was probably not filled by a similar dramatic flood through the Bosphorus. Alluvial structures and fans in the Black Sea floor, show that it silted up from the north, and almost certainly overflowed the Bosphorus from the north, which is why the Bosphorus is relatively narrow - not the whole Med carving wide straits, but a freshwater trickle out from the silted Black Sea.
P.P.S. Also note this contradicts some imagined historical basis for the Gilgamesh and Biblical floods being in the Black Sea (in the direction of what is now called Mt. Ararat). Those tales are much more likely to refer to Mesopotamian floods of the Tigris or Euphrates, perhaps triggered by breaching of earthquake-induced rockslides that temporarily blocked one of the rivers. We can now date and locate a specific episode like this in ancient China 4,000 years ago:
https://www.nationalgeographic.com/science/article/china-yel...
Thank you. I fail to grasp your P.S. in relation to the Levant passage ?
Avoid using clickbaity YT videos as source, they are entertainment and not reliable.
I did say like not believe.
Specific errors?
Counter references?
Specific errors?
Counter references?
> Counter references?
Bold. You presented no citable references, either.
Bold. You presented no citable references, either.
I summarized some factual statements - any of them wrong?
Why is the burden on me? Are any of them right?
Thats better. If you want go get even better, scroll down to the "References" section and follow from there to the primary sources. Wikipedia alone is okay-ish but is often faulty because it accepts journalistic pieces (including some YT videos) as source.
That's kind of like saying the internet is not reliable. Don't post links. Ok. So now what?
Only studies, only peer-reviewed studies?
Only peer-reviewed studies published by qualified sources?
Only videos based on peer-reviewed studies published by approved sources, that have passed a committees on the non-biased use of artistic representations of special effects in entertainingly but scientifically accurate facts?
This whole, nothing is real, there is no truth, is really out of control.
Only studies, only peer-reviewed studies?
Only peer-reviewed studies published by qualified sources?
Only videos based on peer-reviewed studies published by approved sources, that have passed a committees on the non-biased use of artistic representations of special effects in entertainingly but scientifically accurate facts?
This whole, nothing is real, there is no truth, is really out of control.
No its not. You are making a bad strawman.
YT content creators are financially incentivized to exaggerate things to generate user engagement. This is a conflict of interests.
A good source would be something that has its own sources cited or directly comes with evidence.
YT content creators are financially incentivized to exaggerate things to generate user engagement. This is a conflict of interests.
A good source would be something that has its own sources cited or directly comes with evidence.
That might be an appropriate threshold for Wikipedia, but not for HN.
To that point, HN commenters are also directly incentivized to say certain things because of the way the voting works. You can get a lot of upvotes just by seeming profound (especially if you have a reputation) or "rational" without being either of those things because few people have the time and energy to dissect comments beyond first impressions. Bonus points if you can cite a study even if it does not actually say what you claim or is otherwise dubious (because after all, dismissing it based on the author would be an "ad hominem", right?).
The problem HN has with YT content creators being motivated by certain factors is not that they're less trustworthy but that they're tacky. Like Reddit (a social link sharing site with commenting and a heavily polarized community) which is nothing like HN (a social link sharing site with commenting and a heavily polarized community).
The problem HN has with YT content creators being motivated by certain factors is not that they're less trustworthy but that they're tacky. Like Reddit (a social link sharing site with commenting and a heavily polarized community) which is nothing like HN (a social link sharing site with commenting and a heavily polarized community).
"financially incentivized" -> Welcome to the world.
You can search HN and find plenty of arguments that scientific reporting by all major journals are biased and no longer factual and are just clickbait.
Researchers have 'clickbait' studies because they are "financially incentivized" to get funding.
You are drawing the line at YouTube, others draw the line at CNN, others draw the line at freaking 'Nature'.
Now AI is generating scientific papers, I think we should be worried about how we determine 'factual' sources across the board.
You can search HN and find plenty of arguments that scientific reporting by all major journals are biased and no longer factual and are just clickbait.
Researchers have 'clickbait' studies because they are "financially incentivized" to get funding.
You are drawing the line at YouTube, others draw the line at CNN, others draw the line at freaking 'Nature'.
Now AI is generating scientific papers, I think we should be worried about how we determine 'factual' sources across the board.
That argumentation does not work out - arguing that "proper science" is not much better does not make that YT video any more reliable.
Not 'science', our reporting of science.
We no longer have trusted sources for 'facts'.
Lots of science is reported on YT and it is fine. You can't take a study in 'Nature' and say it is fine, but then if that study is reported in a video on YT, now it is in question. The video on the flood above was fine, there was nothing incorrect in it, why is it 'wrong' by being on YT?
Maybe a % of garbage rating? But who does the judging?
We no longer have trusted sources for 'facts'.
Lots of science is reported on YT and it is fine. You can't take a study in 'Nature' and say it is fine, but then if that study is reported in a video on YT, now it is in question. The video on the flood above was fine, there was nothing incorrect in it, why is it 'wrong' by being on YT?
Maybe a % of garbage rating? But who does the judging?
I can understand why ancient people would migrate west or east since the sun movement; rise or set would draw them there. What would spur people to move north or south other than hunting animals? If animals I'd expect north for a bit then south again (or vice versa below the equator).
Are there popular competing theories like https://www.researchgate.net/publication/21589761_The_Multir... ?
This paper seems to be referencing the migration of Homo Erectus which occurred earlier and is generally agreed upon (though the specifics are still widely debated, thus the paper).
Multiregional Evolution posits that modern Humans evolved directly from these distributed pockets of Homo Erectus, while the competing Out of Africa theory suggests that anatomically modern humans evolved once in Africa and then spread to the rest of the world, outcompeting the prior hominoid species as they went.
My understanding is that the MRE hypothesis was largely discarded in favor of Out of Africa based on genetic data in the early 00s. Studies show that all humans share mitochondrial DNA (mtDNA), Y-chromosome DNA, and autosomal DNA ancestors which is not what you'd expect if humans evolved separately multiple times.
The big compromise of the model which has emerged in recent years is Out of Africa with Admixture. Basically saying that Homo Sapiens didn't just outcompete other local hominoid branches but interbred with them to a meaningful extent. This was originally not well supported but there's a growing body of work to support it and I believe the academic community is coming around. You see this most strongly with Neanderthals in Europe, for instance.
Multiregional Evolution posits that modern Humans evolved directly from these distributed pockets of Homo Erectus, while the competing Out of Africa theory suggests that anatomically modern humans evolved once in Africa and then spread to the rest of the world, outcompeting the prior hominoid species as they went.
My understanding is that the MRE hypothesis was largely discarded in favor of Out of Africa based on genetic data in the early 00s. Studies show that all humans share mitochondrial DNA (mtDNA), Y-chromosome DNA, and autosomal DNA ancestors which is not what you'd expect if humans evolved separately multiple times.
The big compromise of the model which has emerged in recent years is Out of Africa with Admixture. Basically saying that Homo Sapiens didn't just outcompete other local hominoid branches but interbred with them to a meaningful extent. This was originally not well supported but there's a growing body of work to support it and I believe the academic community is coming around. You see this most strongly with Neanderthals in Europe, for instance.
There's no compromise model. Admixture with archaic hominins is widely accepted these days, but it's simply a small asterisk on top of OOA for essentially everyone outside China (where MRE remains popular).
The honest interpretation of DNA evidence is that Cro-Magnon man mixed with the Neanderthals and Denisovans and then likely migrated into Africa, not out of it.
caust1c(1)
And today it's driven by bad policy. Heyoo!
Well, exploiting their resources for hundreds of years, then granting them "independence" while keeping a financial and economic stranglehold along with ill-fated financial "aid" projects offering cheap loans to build an export-focused penny economy and bringing in foreign companies rather than focusing on local sustainability and then bombing them or assassinating their leaders (or installing dictators) when you don't like the direction they're headed is a bit more complex than "bad policy".
Though to be fair, a lot of that also applies to South America and the Middle East.
Though to be fair, a lot of that also applies to South America and the Middle East.
The first waves were not of anatomically modern humans but Homo erectus and its contemporaries up into modern Georgia, then East into China, then eventually into Indonesia.
Then around 1 million years later, there was another migration of Homo erectus out into Southeast Asia along the coast through India and eventually into Vietnam and Malaysia.
This second migration seems to be what the paper is referencing and definitely the one that, at least 10 years ago, the anthropology community had the least confidence in. My understanding, again dated by a decade now, is that it was uncertain if hominoids entered Europe at that point or not.
Neanderthals left Africa 500,000 years later into Europe while Denisovans left at the same time into Asia ending up concentrated in Serbia.
Modern Humans don't show up until another 400,000 years after that (around 100,000 years ago) and don't leave Africa until 70,000 years ago. They also left Africa in multiple waves with 5 main ones spreading out across the globe.