Textbook story of how humans populated America is 'biologically unviable,' study finds

August 10, 2016, University of Copenhagen
The fieldwork was conducted during the winter because the frozen lake surface provided the researchers with a solid (but freezing) platform for drilling into the sediment. Credit: Mikkel Winther Pedersen

The established theory about the route by which Ice Age peoples first reached the present-day United States has been challenged by an unprecedented study which concludes that their supposed entry route was "biologically unviable".

The first people to reach the Americas crossed via an ancient land bridge between Siberia and Alaska but then, according to conventional wisdom, had to wait until two huge ice sheets that covered what is now Canada started to recede, creating the so-called "ice-free corridor" which enabled them to move south.

In a new study published in the journal Nature, however, an international team of researchers used ancient DNA extracted from a crucial pinch-point within this corridor to investigate how its ecosystem evolved as the glaciers began to retreat. They created a comprehensive picture showing how and when different flora and fauna emerged and the once ice-covered landscape became a viable passageway. No prehistoric reconstruction project like it has ever been attempted before.

The researchers conclude that while people may well have travelled this corridor after about 12,600 years ago, it would have been impassable earlier than that, as the corridor lacked crucial resources, such as wood for fuel and tools, and game animals which were essential to the hunter-gatherer lifestyle.

If this is true, then it means that the first Americans, who were present south of the ice sheets long before 12,600 years ago, must have made the journey south by another route. The study's authors suggest that they probably migrated along the Pacific coast.

Who these people were is still widely disputed. Archaeologists agree, however, that early inhabitants of the modern-day contiguous United States included the so-called "Clovis" culture, which first appear in the archaeological record over 13,000 years ago. And the new study argues that the ice-free corridor would have been completely impassable at that time.

The research was led by Professor Eske Willerslev, an evolutionary geneticist from Centre for GeoGenetics, University of Copenhagen and University of Cambridge, who also hold posts at St John's College and the Wellcome Sanger Institute.

A present day view north in the area where the retreating ice sheets created the ice free corridor more than 13,000 years ago. Credit: Mikkel Winther Pedersen

"The bottom line is that even though the physical corridor was open by 13,000 years ago, it was several hundred years before it was possible to use it," Willerslev said.

"That means that the first people entering what is now the US, Central and South America must have taken a different route. Whether you believe these people were Clovis, or someone else, they simply could not have come through the corridor, as long claimed."

Mikkel Winther Pedersen, a PhD student at the Centre for GeoGenetics, University of Copenhagen, who conducted the molecular analysis, added: "The ice-free corridor was long considered the principal entry route for the first Americans. Our results reveal that it simply opened up too late for that to have been possible."

The corridor is thought to have been about 1,500 kilometres long, and emerged east of the Rocky Mountains 13,000 years ago in present-day western Canada, as two great ice sheets - the Cordilleran and Laurentide, retreated.

On paper, this fits well with the argument that Clovis people were the first to disperse across the Americas. The first evidence for this culture, which is named after distinctive stone tools found near Clovis, New Mexico, also dates from roughly the same time, although many archaeologists now believe that other people arrived earlier.

"What nobody has looked at is when the corridor became biologically viable," Willerslev said. "When could they actually have survived the long and difficult journey through it?"

The conclusion reached by Willerslev and his colleagues is that the journey would have been impossible until about 12,600 years ago. Their research focused on a "bottleneck", one of the last parts of the corridor to become ice-free, and now partly covered by Charlie Lake in British Columbia, and Spring Lake, Alberta - both part of Canada's Peace River drainage basin.

Map outlining the opening of the human migration routes in North America revealed by the results presented in this study. Credit: Mikkel Winther Pedersen

The team gathered evidence including radiocarbon dates, pollen, macrofossils and DNA taken from lake sediment cores, which they obtained standing on the frozen lake surface during the winter season. Willerslev's own PhD, 13 years ago, demonstrated that it is possible to extract ancient plant and mammalian DNA from sediments, as it contains preserved molecular fossils from substances such as tissue, urine, and faeces.

Having acquired the DNA, the group then applied a technique termed "shotgun sequencing". "Instead of looking for specific pieces of DNA from individual species, we basically sequenced everything in there, from bacteria to animals," Willerslev said. "It's amazing what you can get out of this. We found evidence of fish, eagles, mammals and plants. It shows how effective this approach can be to reconstruct past environments."

This approach allowed the team to see, with remarkable precision, how the bottleneck's ecosystem developed. Crucially, it showed that before about 12,600 years ago, there were no plants, nor animals, in the corridor, meaning that humans passing through it would not have had resources vital to survive.

Around 12,600 years ago, steppe vegetation started to appear, followed quickly by animals such as bison, woolly mammoth, jackrabbits and voles. Importantly 11,500 years ago, the researchers identified a transition to a "parkland ecosystem" - a landscape densely populated by trees, as well as moose, elk and bald-headed eagles, which would have offered crucial resources for migrating humans.

Somewhere in between, the lakes in the area were populated by fish, including several identifiable species such as pike and perch. Finally, about 10,000 years ago, the area transitioned again, this time into boreal forest, characterised by spruce and pine.

The fact that Clovis was clearly present south of the corridor before 12,600 years ago means that they could not have travelled through it. David Meltzer, an archaeologist at Southern Methodist University and a co-author on the study, said: "There is compelling evidence that Clovis was preceded by an earlier and possibly separate population, but either way, the first people to reach the Americas in Ice Age times would have found the corridor itself impassable."

"Most likely, you would say that the evidence points to their having travelled down the Pacific Coast," Willerslev added. "That now seems the most likely scenario."

Explore further: Ice age bison fossils shed light on early human migrations in North America

More information: Mikkel W. Pedersen et al, Postglacial viability and colonization in North America's ice-free corridor, Nature (2016). DOI: 10.1038/nature19085 Mikkel W. Pedersen et al. Postglacial viability and colonization in North America's ice-free corridor, Nature (2016). DOI: 10.1038/nature19085

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huckmucus
5 / 5 (4) Aug 10, 2016
Was the bottleneck a high spot in the corridor? As one of the last places to be ice free, could it be that the evidence is not representative of the whole corridor? At 1500 klicks it might take a month or two to cross. But if the distance was much less, they could cross it with satchels of meat, etc. Water surely was not a problem. I'm not challenging the sea route. I just have faith in adventure and the ability to hump long distances with kit and vittles.
torbjorn_b_g_larsson
5 / 5 (2) Aug 10, 2016
Then again, that date is slightly in tension with the evolutionary evidence from bison that suggets the cooridor was ice free already 13 kyrs ago.

"Archaeologists once thought a narrow strip of land opened up between the glaciers, allowing them passage. But others suspect the migrants hopped down the Pacific coast in boats long before that happened. Now, a new study of bison fossils offers the most precise date yet for the opening of the ice-free corridor: 13,000 years ago. Combined with evidence of earlier occupations in the lower 48, it suggests the corridor could not have been the first route people took into the New World.

"This is the first strong empirical data indicating when that corridor was viable," says Michael Waters, an archaeologist at Texas A&M University, College Station. "It's indirect evidence, but it's still strong evidence.""

[ http://www.scienc...americas ]
torbjorn_b_g_larsson
5 / 5 (2) Aug 10, 2016
And:

"... to tell which group a bison fossil belonged to, all she had to do was sequence its mitochondrial DNA. Finding a southern bison in the north or a northern bison in the south would indicate that the animals were successfully traversing the ice-free corridor. Radiocarbon dates from collagen in the fossils could reveal exactly when that had happened.

Northern and southern bison were mingling within the ice-free corridor by about 13,000 years ago, the team reports online today in the Proceedings of the National Academy of Sciences. That's right around the first appearance of Clovis points. But it's well after a handful of sites dated to the pre-Clovis period, including Page-Ladson in Florida, where archaeologists recently discovered a 14,500-year-old stone biface.

Still, the corridor may have been important for people on the move. "It may not have been Highway 1" into the New World, Ives says. "But it was Highway 2.""
jonesdave
4 / 5 (4) Aug 10, 2016
Was the bottleneck a high spot in the corridor? As one of the last places to be ice free, could it be that the evidence is not representative of the whole corridor? At 1500 klicks it might take a month or two to cross. But if the distance was much less, they could cross it with satchels of meat, etc. Water surely was not a problem. I'm not challenging the sea route. I just have faith in adventure and the ability to hump long distances with kit and vittles.


No, I doubt it is only representative of a small area, given that they sampled pollen, among other things, which would blow in from some distance away.
SciTechdude
5 / 5 (4) Aug 10, 2016
Boats, not that hard to do if you stick to the coast.
RealScience
5 / 5 (3) Aug 10, 2016
While some early occupation dates (such as Monte Verde) strongly suggest a sea route, this article is too dismissive of what a person could accomplish.

Powdered meat+berries in fat has protein and vitamins as well as ~7000 calories/kilo. Three kilos per week provides enough energy to hike ~20 kilometer a day, or ~150 km a week, over seriously rugged terrain.

Even I used to hike with a 45 kilo pack, which would allow 30 kilos of pemmican, which would allow traversing the entire 1500 km without stopping to hunt. People who spent their lives hunting on foot could probably carry enough more and move enough faster to have twice that at range, or 1500 km with enough food to return if one finds nothing.

A few good years of hunting would provide a summer of freedom, so even if the entire 1500 km were barren, some teenagers would probably do it on a dare, and come back with the news that there was a land where the animals had no fear of people!
huckmucus
5 / 5 (3) Aug 10, 2016
A few good years of hunting would provide a summer of freedom, so even if the entire 1500 km were barren, some teenagers would probably do it on a dare, and come back with the news that there was a land where the animals had no fear of people!


These were my thoughts as well. I think many folks underestimate our abilities to truck along. We spread, fill up, and quit spreading due to neighbors. Then the wars start. Oh, but to be the first folks in-country!
rrrander
3 / 5 (2) Aug 11, 2016
Have they managed to re-bury Kennewick man yet? He was an embarrassment to the establishment.
Eikka
not rated yet Aug 11, 2016
At 1500 klicks it might take a month or two to cross.


That is if you know what you're doing and know the geography, and are purposefully crossing the distance.

Even I used to hike with a 45 kilo pack, which would allow 30 kilos of pemmican, which would allow traversing the entire 1500 km without stopping to hunt.


But can you get back without stopping to hunt? Going 1500 km across barren land until your food runs out, without knowledge of whether you can replenish, is basically a suicide mission. How do you know how much to take along if you don't know how far you'll have to go?

And you also need a team to carry supplies for shelter and crossing rivers and lakes and mountains, and fighting off predators and hunting for more food once you get to the other side, so it's not just a simple matter of a lone teenager with a backpack hiking all the way.

A whole purposeful expedition is unlikely with the early cultures.
huckmucus
5 / 5 (1) Aug 11, 2016
That is if you know what you're doing and know the geography, and are purposefully crossing the distance.


If any humans who ever walked this planet knew what they were doing, and knew their geography, it was them. We have lost SO much that they had as a matter of course. They could climb a mountain and read the terrain and the weather forever in every direction. They likely had the skills of big game and small game hunters, combined with the arctic desert know-how of the Inuit. And it was probably more than one teen.

If the bottleneck was the last to clear, then I doubt the whole 1,500 was barren. The first to clear would already have plants and animals moving in. And, as already stated, you could go half way and turn around if it didn't look promising. Not a suicide mission.
EnsignFlandry
not rated yet Aug 11, 2016
Small groups of people from several regions probably made it to the Americas, but one group was overwhelmingly predominant.
RealScience
5 / 5 (2) Aug 12, 2016
Even I used to hike with a 45 kilo pack, which would allow 30 kilos of pemmican, which would allow traversing the entire 1500 km without stopping to hunt.


But can you get back without stopping to hunt? Going 1500 km across barren land until your food runs out, without knowledge of whether you can replenish, is basically a suicide mission. How do you know how much to take along if you don't know how far you'll have to go?

1500 km would have been my personal range. As I pointed out, someone who hunted for a living in similar terrain would have ~twice the range, and could thus go until the food was ~half gone, which would be far enough.

A whole purposeful expedition is unlikely with the early cultures.

Hunter-gatherers often travel long distances following a favorite food animal's migration. These are people whose ancestors had already made it through Siberia to Alaska.
RealScience
5 / 5 (2) Aug 12, 2016
If any humans ever walked this planet knew what they were doing, and knew their geography, it was them.... They likely had the skills of big game and small game hunters, combined with the arctic desert know-how of the Inuit. And it was probably more than one teen.


And they would see birds migrating south over the ice in the fall and returning in the spring, so there must some land to the south where food was available even in the winter...

Bogs might not yet have formed, but river crossings would be a problem.
However the dog sled is known from Yakutia >8000 years ago and is also known in the Americas, so it probably predates this journey. That would make a winter journey the way to go - otherwise it is a late summer trip and much riskier.

I still favor the sea route hypothesis for the first migration south, but I object to claims that 1500 km of barren land could not be crossed.
Pediopal
not rated yet Aug 13, 2016
Have they managed to re-bury Kennewick man yet? He was an embarrassment to the establishment.


Well Doug Owsley and his crazy BS certainly was for sure. But then the Smithsonian kept letting him blather the BS so they are as culpable as he is.

As far as Kennewick man, no he has not been repatriated. Doug Owsley is fighting it tooth and nail. E ven after making an ass out of himself good ol' Dougie just cannot slither back into the hole he has dug for himself.
Eikka
not rated yet Aug 13, 2016
And they would see birds migrating south over the ice in the fall and returning in the spring, so there must some land to the south where food was available even in the winter...


It's easy to perform the historian's fallacy over what earlier cultures knew and did. In some old Scandinavian mythology, they believed migrating birds were diving to the bottom of lakes and crossing over to the death realm to spend the winter.

And that's from the cultures that invented the sunstone compass for navigation and crossed the Atlantic. What you see and how you percieve it isn't always one to one - the prehistoric people were operating on very different paradigms to ours.

RealScience
5 / 5 (1) Aug 13, 2016
It's easy to perform the historian's fallacy over what earlier cultures knew and did. In some old Scandinavian mythology, they believed migrating birds were diving to the bottom of lakes and crossing over to the death realm to spend the winter.

@Eikka:
Yes, people MIGHT not have concluded that birds eat, or MIGHT have some reason not to cross the divide (e.g., superstition). However they also MIGHT have concluded that birds eat in winter, or MIGHT have had a culture that favors exploring (after all, their recent ancestors had already crossed from Siberia).

I thought my posts were clear that I favor the coastal route, and that I'm not saying that the between-the-ice crossing DID happen (either pre- or post-vegetation), but that I'm disagreeing with the study's premise that it COULD NOT have happened before vegetation).

Are you agreeing with the premise that the 1500 km crossing COULD NOT have been made before it was vegetated and had game animals?
huckmucus
not rated yet Aug 13, 2016
It's easy to perform the historian's fallacy over what earlier cultures knew and did. In some old Scandinavian mythology, they believed migrating birds were diving to the bottom of lakes and crossing over to the death realm to spend the winter.

And that's from the cultures that invented the sunstone compass for navigation and crossed the Atlantic. What you see and how you percieve it isn't always one to one - the prehistoric people were operating on very different paradigms to ours.


It's even easier to perform the fallacy of thinking intimacy and wisdom subordinate to objectivity and data. The wolf is greater than the sum of it's parts. Quite simply, we've lost as much as we've gained.
RealScience
not rated yet Aug 14, 2016
...we've lost as much as we've gained.


Individually, yes. our brain capacity does not appear to have increased since neolithic (there is even evidence that our brains are slightly smaller), so while we now learn about a wider world, we learn less detail about out local environment.

However In hunter-gatherer societies nearly everyone knows the same survival basics, and the number of specialties (flint knapper, shaft maker, shaman, herbalist, best tracker, etc.) is fairly limited, so in a society of a few dozen, the total knowledge is probably <10x the knowledge of an individual, and this is largely duplicated from group to group.

In contrast we now have many thousands of specialties so the total information in our society is several orders of magnitude larger than in neolithic times.

(However on a 1500 km trek between these ice sheets, the skills and knowledge of a society that had already explored their way from Siberia would be a perfect match!)
huckmucus
5 / 5 (1) Aug 14, 2016
With genocide and disease/elimination of countless tribes and clans of hunter-gatherers, along with the environments in which they lived, we also lost unknown knowledge and wisdom that "we" once had.

It's not like it was accumulated and bequeathed to a collective human data base that some of us can still specialize in. Even if it was somehow retained somewhere, there is a world of difference between "having it" and "knowing it." How a plant does something is cool to know. But if you don't know that it can do it, you are at least as ignorant as the guy that does, even if he doesn't know how. We might even render it extinct never knowing what it could have done for us.

Just like extinct languages, there are tonal inflections and other nuance in a relationship with the Earth that are beyond the cold laboratory and once lost, they are lost for good.

I'll take quality *and* quantity, but err with the former.
RealScience
not rated yet Aug 14, 2016
How a plant does something is cool to know. But if you don't know that it can do it, you are at least as ignorant as the guy that does, even if he doesn't know how. We might even render it extinct never knowing what it could have done for us.


Agreed - people were very good observers of 'what', and even of how to reproduce something, long before we started digging into the how and why of a process itself. We had steels with carbon nanotubes and cementite nanofibers thousand of years before we knew why these steels were so strong, for example.

But I like both types of knowledge - for example I've hand-hewn my own barn beams and become a half-decent herbalist etc. as hobbies to balance my science/engineering work in technical fields.

I'll take quality *and* quantity, but err with the former.

Agreed! Quality knowledge brings understanding that lets it be applied to diverse problems, while low-quality information is typically only narrowly useful.
dustywells
not rated yet Aug 14, 2016
15,000 years ago sea level was 100 meters lower than it is today. Migration would have been along the coast as it was then and evidence of habitation has to be searched under water not in the mountains.
Eikka
not rated yet Aug 15, 2016
Are you agreeing with the premise that the 1500 km crossing COULD NOT have been made before it was vegetated and had game animals?

(However on a 1500 km trek between these ice sheets, the skills and knowledge of a society that had already explored their way from Siberia would be a perfect match!)


You're talking about a pre-historic society with very little effective means of passing complex information over generations other than showing them by hand. Even the word "society" is feeble at this point.

That means, when they roamed from Siberia over many generations, each generation only learned the skills necessary at the point where they were at. A new generation born along the way would not have possessed the same skills and information as the one before, and so skill and information is actively lost.

You can't assume "oh their ancestors came from Siberia, therefore they must know how to make a 1500 km trek across a barren glacier pass".
Eikka
not rated yet Aug 15, 2016
Point being that the hunter-gatherer groups don't really make 1500 km treks in one generation. They have no reason to if there's food and shelter to be found closer. They're going to go the path of the least resistance and set up camp as soon as they can find something to eat, and if there seems to be nothing for miles and miles they turn back and return where there was something to eat and trees for fuel and housing etc.

It's a question of why would you cross it, if there's a faster, easier coastal route down that doesn't require you to risk life and limb, that is naturally found by following the prey animals that won't go down the glacier pass because there's no vegetation for them in there either.

There seems to be no reason for the people to even attempt the crossing until it got easier to cross and they already knew what's on the other side.
Eikka
not rated yet Aug 15, 2016
For example, the prey animals such as the Alaskan Caribou, naturally migrate along the coast and throught the forests. They would not have taken the glacier pass either, although they could go the distance in a month in a hurry, because the animals are following the food as well. Besides, 1500 km is at the top end of what they would actually migrate in a straight line between their winter and summer ranges.

So for the ancient people, if they were nomadic hunters, they would not cross the pass until the animals started crossing it - not without a special reason. If they were more sedentary hunter-gatherers instead of nomads, they would cross the distance over multiple generations of advancing settlements.
huckmucus
not rated yet Aug 15, 2016
Eikka: Your posts remind me of anthropomorphism: you impute your thinking to people you admit you have nothing in common with. By your reasoning, people you have nothing in common with never would have gone to the moon. Further, you think this was all generational creep across Siberia. There is no evidence for that. Study the wolf pack, lone wolves, the starting of new packs and distances traveled.

The real insult is your notion about the failure of inter-generational transfer of knowledge.

As to the coast, are we sure the glaciers didn't go right down in to the sea? I always thought the coastal route was a boat route? If so, no caribou to follow.
Eikka
not rated yet Aug 15, 2016
you impute your thinking to people you admit you have nothing in common with.


On the contrary. I'm trying to think what they might have thought and what information and skills, and motivations they would have had. I.e. what sort of people they were, not what sort of a person I am.
By your reasoning, people you have nothing in common with never would have gone to the moon.


I don't see how that follows from anything.

By your reasoning, people you have nothing in common with never would have gone to the moon. Further, you think this was all generational creep across Siberia. There is no evidence for that.


It's very very unlikely that it was some mad dash across the strait in a single human lifetime, because you need many thousands of people to make the way to form viable populations. One family or small group in isolation is not viable because of the problem of inbreeding.
Eikka
not rated yet Aug 15, 2016
As to the coast, are we sure the glaciers didn't go right down in to the sea? I always thought the coastal route was a boat route? If so, no caribou to follow.


Yes, it is pretty much given that the coasts would be ice-free. It would be a jigsaw puzzle of islands and river deltas from the receding continental ice. Quick to travel up and down by boat, but also possible to settle along the way to form the continuous population link.

And caribou are excellent swimmers, and the people would have also subsisted on fishing. The whole argument is that taking the inland route offers so little in terms of sustenance that the people really would have had to know what they were doing and have a good purpose to cross it - it's unlikely they just wandered down that way, and it's uncharacteristic of the sort of cultures to make such expeditions on purpose.
Eikka
not rated yet Aug 15, 2016
The real insult is your notion about the failure of inter-generational transfer of knowledge.


It only takes two generations for living verbal memory to become legend and specific knowledge lost. The particulars of, say, constructing a dog-sleigh or a seal-skin boat, or how to prepare certain foods and herbs, cannot be passed down the generations that way. That information has to be hands-on from parent to child, and to be hands-on it has to be necessary for the people to actually do it.

If a group spends two-three generations exclusively fishing along the coast, they soon forget how to roam with the migrating animals because there's nobody alive with the living memory of doing it, and the rest are just operating on legend. They have to re-discover the skillset to move inland.

Verbal history is like the game of broken telephone. The details quickly vanish or distort along the way.
Dug
1.8 / 5 (5) Aug 15, 2016
The assumption that food and fuel were human migration limiting and non-existent on a barren landscape is the weak link in this theory. Northern people have produced food, fuel, transportation and shelter from ice and or marine mammals - meat, oil, bones, skins - in polar environments without the need for significant amounts of wood or terrestrial game for eons.
huckmucus
not rated yet Aug 15, 2016
It only takes two generations for living verbal memory to become legend and specific knowledge lost.


1. There is no evidence that any such break occurred or would occur in moving from Siberia, over to the area north of the pass and then down through it. Indeed, the continuity on generational transfer of knowledge would be continuous.

2. To the extent your entire most recent post is true (I could dispute that, but here I am not) then just imagine the garguantuan gap between those people and a modern day urbanite in a lab with no real intimacy with the Earth.
Eikka
5 / 5 (1) Aug 15, 2016
Northern people have produced food, fuel, transportation and shelter from ice and or marine mammals - meat, oil, bones, skins - in polar environments without the need for significant amounts of wood or terrestrial game for eons.


There wouldn't be any seals or other large marine animals inland between the glaciers. The whole place would be more or less a rocky desert with perhaps a little moss on the rocks and a few patches of weeds.

It would look somewhat like this the whole way: http://www.greenp...ayas.jpg

The problem is that the meltwater from the glaciers when the pass opens up washes away all the topsoil and leaves just fields and rifts of boulders and gravel and sand, and the flooding process repeats multiple times as the ice around melts into pools and breaks free.
huckmucus
not rated yet Aug 15, 2016
If a group spends two-three generations exclusively . . . .


"Exclusively" is the ruination of the argument. If you believe in the slow creep theory of human migration then I guess I can see how a group *might* become "exclusive." But humans are rarely exclusive. They are generalists that exploit whatever they can. They may fish on the coast but they hunt inland, from low to high elevations, and they eat anything edible. They would maintain their skill sets, particularly when it comes to reading weather and terrain.
huckmucus
not rated yet Aug 15, 2016
There wouldn't be any seals or other large marine animals inland between the glaciers.


I took Dug's post as drawing analogy to long stretches of time and distance sustained by food gathered during short periods in an icy, unforgiving desert with no wood for fuel. I did not take his post as suggesting there was any game or wood in the gap.
Eikka
not rated yet Aug 15, 2016
There is no evidence that any such break occurred or would occur in moving from Siberia, over to the area north of the pass and then down through it.


What sort of evidence would you require? A written record? "Today we realized nobody remembers how to hunt deer". The point is that the groups that do not live a nomadic migrating lifestyle, that are more used to living along the coast and fishing won't just suddenly trek 1500 km across a desert of rocks for a dare even if their ancestors had at some point done so tens of generations earlier.

Indeed, the continuity on generational transfer of knowledge would be continuous.


For as long as the people remain connected to a larger continous population that can transfer them the knowledge. Problem being that people living even a few hundred kilometers apart from each other in relative isolation for generations tend to not even speak the same language after a while.
huckmucus
not rated yet Aug 15, 2016
What sort of evidence would you require?


Evidence that they stopped living a nomadic migrating lifestyle.

For as long as the people remain connected to a larger continous population that can transfer them the knowledge. Problem being that people living even a few hundred kilometers apart from each other in relative isolation for generations tend to not even speak the same language after a while.


You are confusing these people with sedentary agriculturalists; or you're still thinking in terms of gradual creep. There is no evidence they lived in relative isolation for generations.
Eikka
not rated yet Aug 15, 2016
If you believe in the slow creep theory of human migration then I guess I can see how a group *might* become "exclusive."


It's plausible, because the alternative requires sudden mass-migrations that involve thousands, that all just up-and decide to march across to some destination unknown to them for reasons unknown to us.

All the plausible reasons why the individual people moved would be because their food went there, such as migrating caribou that started roaming further south as the ice receded, or because they faced population pressures and had to pitch their tents a stone's throw further away to avoid conflict. In either case, the change is gradual, not a sudden leap in one generation.

The groups need the continuous contact with the larger population to e.g. swap wives with other tribes, or trade for tools and materials - they're not perfectly self-sufficient - so no individual family can migrate very far at a time.
Eikka
not rated yet Aug 15, 2016
Evidence that they stopped living a nomadic migrating lifestyle.


Of course there isn't, because some people did and some people didn't. The people who stayed put and established a territory quickly lost the cultural heritage and skills of nomadism.

The problem with the latter is, why would a tribe be nomadic? They're not living the lifestyle for fun, but because they're going after sustenance - animals - and why would animals cross the glacier pass before there's anything to eat in there? Why would the people go where the animals don't?

You are confusing these people with sedentary agriculturalists;


Being a hunter-gatherer doesn't mean you have to roam as a nomad.

There is no evidence they lived in relative isolation for generations.


These are hunter-gatherer cultures - they're territorial and isolationist by nature. The individual groups don't particularily like each other because they're competing for natural resources.
huckmucus
not rated yet Aug 15, 2016
It's plausible, because the alternative requires sudden mass-migrations that involve thousands, that all just up-and decide to march across to some destination unknown to them for reasons unknown to us.

The groups need the continuous contact with the larger population to e.g. swap wives with other tribes, or trade for tools and materials - they're not perfectly self-sufficient - so no individual family can migrate very far at a time.


It is my understanding they were groups of 30 to 60 people and they were perfectly self-sufficient. They may have linked up seasonally to swap mates but 10,000 square miles of territory is only 50 miles to meet in the middle. They find the gap. One group goes through. Sends some folks back to give the all-clear and the other group comes through, then another, then another and they spread out in North America likewise.
huckmucus
not rated yet Aug 15, 2016
The people who stayed put and established a territory quickly lost the cultural heritage and skills of nomadism.


We aren't talking about them.

The problem with the latter is, why would a tribe be nomadic?


For fun. Arts and crafts and culture come from time and abundance. We don't lay around, fat, burp and fart with a full belly. We explore. It's who we are. It's why we covered the globe.

Being a hunter-gatherer doesn't mean you have to roam as a nomad.


Doesn't hurt, obviously.

These are hunter-gatherer cultures - they're territorial and isolationist by nature. The individual groups don't particularily like each other because they're competing for natural resources.


Only when there is no new territory to fill. You are confusing these people with the tribes that arose after the continent was occupied. Even they maintained the contacts you demanded above.
Eikka
not rated yet Aug 15, 2016
For fun.


As I said, I very much doubt that they had that much free time from their main occupation of surviving.

Doesn't hurt, obviously.


Yes it does, obviously, because if you roam too much you can't maintain your territory, and losing territory means you lose the gathering part of your hunter-gatherer lifestyle because someone else moves in where you used to trap and collect mushrooms etc. and they don't like you around.

Only when there is no new territory to fill.

Mind you, they had limited territory because of the whole continental ice sheet business, and from being pushed from behind by other migrating groups.

The migration pressure can relieve itself more easily down the coast than through the inland, so it's much more likely the people were already down south when the pass opened for transit, rather than trekking down through the just-opened corridor for "fun".
huckmucus
not rated yet Aug 15, 2016
As I said, I very much doubt that they had that much free time from their main occupation of surviving.


I think you are wrong. Hunter-gathers would probably agree.

Yes it does,


No, it does not. Or they would not have got through to the land of abundance. They were NOT trying to hold territory. They were leaving it.

The migration pressure can relieve itself more easily down the coast than through the inland, so it's much more likely the people were already down south when the pass opened for transit, rather than trekking down through the just-opened corridor for "fun".


1. I'm not contesting a coastal route. They would take ALL routes.
2. Still waiting to learn about the ice sheets in the ocean. IF there was no coastal land route then it would be by boat.
3. I'll catch up this evening. Bye bye.
RealScience
not rated yet Aug 15, 2016
@Eikka - favoring the coastal route has already been stated several times.

My objection to the article is not about whether people did or did not cross the 1500 km, it is to the article's premise that hunter-gatherers COULD NOT have crossed 1500 km while it was barren.

Do you agree with the article's premise that the 1500 km crossing COULD NOT have been made before it was vegetated and had game animals?
450BushmasterGuy
5 / 5 (1) Sep 05, 2016
The so-called "ice-free corridor" was their best guess 50 years ago. That it never existed has been known for some time now, as several late studies have shown. Part of the typical arrogance and dismissive attitude normally displayed by virtually all professional archaeologists has been to deny that it was possible for such "primitive" humans to have made it to the Americas by any other means or routes. We now know that there have been multiple waves of immigration into the New World over the millennia including from NW Asia along the Pacific coast; from Melanesia by island hopping; from Africa using the Atlantic trade winds; and along the Ice Age Atlantic ice edges from what is now Spain/Portugal (who BTW are the Clovis People). This will all get sorted out as time goes by and more discoveries are made. The people who are now (mistakenly) known as "Native Americans" are in reality only the second most recent immigrants to the Americas; the most recent being Europeans.
RealScience
not rated yet Sep 05, 2016
@Bushmaster - agreed on the arrogance and dismissive attitude - even after Thor Heyerdahl (among others) repeatedly put his own life on the line to show what was possible, the mainstream still dismissed the capabilities of 'primitive' people.

I'd make a couple of minor changes to what you wrote, to say "there is evidence that" rather than "we now know", and that the 'native americans' are not the second most recent (not only the Europeans, but the Innuit and the Dorset culture are more recent, and Farley Mowat makes a pretty good case for the Albans in "the Far-Farers", and there may be others. And the 'native americans' are also not one wave, but at least two (the Na-dene people being quite distinct.

But I completely agree with you main point - 'primitive' people are quite capable of amazing feats, including getting to the Americas numerous times, and anthropologists grossly under-rate them.

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