6 ms·

A Sunken Bridge the Size of a Continent

113 points by jmadsen 10y ago

sandworm101 10y ago
>This new picture raises a key question: did the first migrants to the Americas really race over Beringia just as the great ice sheets were melting? I'm not sure that I subscribe to land bridges as gateways for early humans to move between continents, especially in the north. The Inuit/Eskimo peoples are and were perfectly capable of moving and living on water, frozen water but water nevertheless. Humans need not have waited to walk across dry land bridges. They were perfectly capable of migrating along ice sheets, or even setting out into open oceans. It would not have been much fun, but the journey would have been made either deliberately or by accident.
- flukus 10y ago
  They did set out into open oceans, it was the only way to get to Australia and that was populated long before the Americas.
  - slyall 10y ago
    Australia was also settled during a glacial maximum so the coastline extended out much further than now. The distance the first migrants to Australia might have needed to travel across open water might have been as low as 90km. https://en.wikipedia.org/wiki/Prehistory_of_Australia#Arrival https://en.wikipedia.org/wiki/Prehistory_of_Australia#Arriva...
    - flukus 10y ago
      A few things to keep in mind: 1. Australia was probably settled well before the Glacial maximum. 2. We don't know much about the coastline, a rocky, volcanic island wouldn't have been a great help to the migrators. 3. They islands they had to go through is a geographically active region (it's possible some people in the migration witnessed the Toba eruption), so knowing where the coastlines were is difficult. 4. Is there a standard for what's considered open ocean? I would consider 45Km to be included, but then again, I would consider grater than 0.1Km to be open ocean.
      - jacalata 10y ago
        4. Yes, but it varies by domain. I think the military definition is the more useful one here: https://definedterm.com/open_ocean https://definedterm.com/open_ocean There are rivers over 100m wide so I don't think that would fit most people's definition.
      - sandworm101 10y ago
        The definition of "open ocean" in my area is that part of the sea unconstrained by the effects of land masses, ie open. It's where waves are defined by wind alone, without any obvious influence of land or shallow. Another version would be those areas where ships may navigate freely without worry of obstructions. That would mean, for sail, that some areas are open or not based on the direction of the wind.
- derefr 10y ago
  The constraint being assumed here, I think, is that it would take a very long time for regular people travelling at a regular pace, and not really knowing where they're going (rather than, say, soldiers on a forced march to a known destination) to cross the Bering strait. It would be longer than preserves would last; it would be longer than bodily essential-nutrient stores would last. Humans need to eat plants. Even the sub-arctic tundra supplies plants to eat, in the summer. But arctic tundra doesn't, and ice sheets certainly don't. Migrating from the arctic tundra in Sibera, across an ice sheet, and then back across the arctic tundra of the Yukon, before finally reaching sub-arctic tundra, would likely take years. It would destroy a person. The advantage of a land bridge isn't that it's not water; it's that it's not ice. It is—for at least some part of the year—arable.
  - thaumasiotes 10y ago
    Believe it or not, Eskimos on the ice eat seals.
  - sandworm101 10y ago
    I don;t think we need plants. If you east whole animals, livers and all, then I believe it possible to survive for an extended period. You won't be happy, but alive.
  - Turing_Machine 10y ago
    The Bering Strait is only 53 miles/85 km wide, and the native peoples of Alaska and Siberia routinely crossed it in their indigenous boats (and over the ice, in winter). Also, there are plenty of plant foods available at the latitude of the Bering Strait. That doesn't really say anything one way or another about the premise of this article, but it's simply not true that a land bridge was required.
- tzs 10y ago
  A water route for the early migrants makes a lot of sense. There was a study published in "Nature" a couple months ago that looked at samples from sediments at choke points on the land routes, and determined that it took several hundred years after the routes opened for vegetation and then animals to appear [1]. During that several hundred years, migrating humans passing through would not be able to live off the land. They'd have to have brought their food with them. Note that this was before the invention of the wheel, so there would be no pulling your supplies with you on a cart. It was also before domestication of any animals other than dogs, so no pilling your supplies on a horse, or having a horse drag a sled. They also would not know how far they would have to go to get to some place that could support them, so would have no idea how much food to take. With the limitation of only being able to take what they could carry, or get dogs to carry, or get dogs to pull on sleds, I doubt that they would have enough to make it through. It's only after the plants and animals get well established, so that you can live off the land, that it becomes reasonably feasible to migrate that way. The Clovis culture was well established long before that, so they had to come some other way, A water route avoids these problems. First, you can carry a lot more with you when you go by boat. You can either make your boat bigger to have room for your supplies, or you can tow a supply boat or raft. (Ropes had been invented by then). Second, you can fish. I don't think the technology of the time would have caught much in the open ocean [2], but if they stayed reasonably close to coastlines they should have been able to catch plenty of fish. (Following coastlines might also be a good idea so they could go ashore now and then to try to find fresh water). What I don't think I've ever seen discussed is when did anyone go the other way? Presumably at some point someone came back and so people in Asia became aware that those who headed east and were never heard from again weren't all starving to death or sailing [3] off the edge of the world or whatever. [1] Here's an article about the study: http://www.history.com/news/new-study-refutes-theory-of-how-humans-populated-north-america http://www.history.com/news/new-study-refutes-theory-of-how-... [2] the open ocean is sometimes described as a "biological desert" because of the sparseness of life there, especially life reasonably near the surface (and so where ancient fisherman could reasonably have a shot at catching it). The overwhelming majority of ocean life is in the shallow seas above the continental shelfs. [3] well...rowing. This was before sails were invented.
  - sandworm101 10y ago
- ralfd 10y ago
  > The Inuit/Eskimo peoples are and were perfectly capable of moving and living on water Suprisingly the Inuit are a very young culture! They started around 1000 AD in Alaska and had settled northern Canada and Greenland only when Europe discovered America. https://upload.wikimedia.org/wikipedia/commons/3/32/Arctic_cultures_900-1500.png https://upload.wikimedia.org/wikipedia/commons/3/32/Arctic_c... The Paleo-Eskimos (genetic studies show no connection to the Inuits, so no intermarriage) developed 2500 BC (and ended 1500 AD), so only 4000 years ago, this is way after the migration of Paleo-Indians into the American continent (40,000–16,500 years ago).
  - sandworm101 10y ago
    I didn't mean to say that they were the culture that made the crossing. They are proof that the move was possible using only the resources available at the time.
  - Turing_Machine 10y ago
    Yes, the Dorset culture was basically genocided by the Inuit. The Inuit actually still have stories about it.
    - Turing_Machine 10y ago
      Apparently someone doesn't like the word "genocide" here. The Dorset were wiped out so thoroughly by the encroaching proto-Inuit that they didn't even leave any genes behind. What would you call it?
205guy 10y ago
I can't believe there is only one (other) top-level comment in this thread, and it's basically anti-science. It doesn't matter what you "subscribe" to, what matters are theories backed by scientifically collected data.
- MichaelBurge 10y ago
  Is history generally considered a science? It would be weird to me for someone to use the scientific method to show that even Abraham Lincoln existed. That's not to say that history isn't a form of knowledge. There's more to knowledge than science.
  - jschwartzi 10y ago
    That's because there's a wealth of documentary evidence showing the Lincoln existed within the past 200 years. Imagine if you were 10,000 years in the future. The United States has ceased to exist, and many of our monuments are buried in mud and rubble. The paper artifacts have mostly rotted away, or they lie buried in some preserving medium. No first-hand accounts remain from the period. One day, a team uncovers a partial statue of a seated man with a great beard. Was he a god, or an emperor of the land? How could they prove either stance without applying scientific techniques, gathering evidence from the remains of the surrounding buildings and analyzing it? Archeology may not be a hard science, but it is an empirical science.
    - DanielBMarkham 10y ago
      I love archaeology. I love evolutionary science. I love anthropology. I'm not replying to you directly here. I have a concern about this thread. I felt this was the best place to put it. Your use of the word "empirical" here may be accurate yet misleading. Some sciences work with hard data, falsifiable hypothesis, repoducibility, and so forth. In these we can construct mathematical models which eventually we trust explicitly. (Note that in most cases these are not explanatory models, simply sufficient ones.) Some sciences work with simple observation and correlation, with lots of imaginative community input in place to suppose causation. We can use mathematical models here as well, but there's a huge degree of noise here. I have no problem with a forum participant coming up with their own speculation. If folks don't like it they can ignore it. Perhaps one day evidence turns up which validates that speculation. We don't shut down those folks by calling them anti-science. Hell, give these people a book contract. The more imaginative narratives you can create from existing data, the more the scientific community at large will expand what they consider to be the world of alternatives to consider. What I'm seeing a lot of lately is taking anything with the label "science" on it and telling laymen that they have no business bullshitting in this area. This is not in the best interest of either science or the academy. ADD: I've seen the flip side of this as well, where really good scientists come up with the most wondrous and dramatic narratives about things where the evidence is thin. That's cool, but many of these folks will use the term "science" as a way of pumping up their speculative fiction. Stringing together a series of what most experts believe is likely while adding your own color commentary is not science. It's entertaining as hell and I love reading it. But it ain't science.
dzdt 10y ago
The map is interesting. I never knew the Aleutian Islands marked a former continental coastline.

113 points by jmadsen 10y ago

>This new picture raises a key question: did the first migrants to the Americas really race over Beringia just as the great ice sheets were melting? I'm not sure that I subscribe to land bridges as gateways for early humans to move between continents, especially in the north. The Inuit/Eskimo peoples are and were perfectly capable of moving and living on water, frozen water but water nevertheless. Humans need not have waited to walk across dry land bridges. They were perfectly capable of migrating along ice sheets, or even setting out into open oceans. It would not have been much fun, but the journey would have been made either deliberately or by accident.

flukus 10y ago
They did set out into open oceans, it was the only way to get to Australia and that was populated long before the Americas.
- slyall 10y ago
  Australia was also settled during a glacial maximum so the coastline extended out much further than now. The distance the first migrants to Australia might have needed to travel across open water might have been as low as 90km. https://en.wikipedia.org/wiki/Prehistory_of_Australia#Arrival https://en.wikipedia.org/wiki/Prehistory_of_Australia#Arriva...
  - flukus 10y ago
    A few things to keep in mind: 1. Australia was probably settled well before the Glacial maximum. 2. We don't know much about the coastline, a rocky, volcanic island wouldn't have been a great help to the migrators. 3. They islands they had to go through is a geographically active region (it's possible some people in the migration witnessed the Toba eruption), so knowing where the coastlines were is difficult. 4. Is there a standard for what's considered open ocean? I would consider 45Km to be included, but then again, I would consider grater than 0.1Km to be open ocean.
    - jacalata 10y ago
      4. Yes, but it varies by domain. I think the military definition is the more useful one here: https://definedterm.com/open_ocean https://definedterm.com/open_ocean There are rivers over 100m wide so I don't think that would fit most people's definition.
    - sandworm101 10y ago
      The definition of "open ocean" in my area is that part of the sea unconstrained by the effects of land masses, ie open. It's where waves are defined by wind alone, without any obvious influence of land or shallow. Another version would be those areas where ships may navigate freely without worry of obstructions. That would mean, for sail, that some areas are open or not based on the direction of the wind.
derefr 10y ago
The constraint being assumed here, I think, is that it would take a very long time for regular people travelling at a regular pace, and not really knowing where they're going (rather than, say, soldiers on a forced march to a known destination) to cross the Bering strait. It would be longer than preserves would last; it would be longer than bodily essential-nutrient stores would last. Humans need to eat plants. Even the sub-arctic tundra supplies plants to eat, in the summer. But arctic tundra doesn't, and ice sheets certainly don't. Migrating from the arctic tundra in Sibera, across an ice sheet, and then back across the arctic tundra of the Yukon, before finally reaching sub-arctic tundra, would likely take years. It would destroy a person. The advantage of a land bridge isn't that it's not water; it's that it's not ice. It is—for at least some part of the year—arable.
- thaumasiotes 10y ago
  Believe it or not, Eskimos on the ice eat seals.
- sandworm101 10y ago
  I don;t think we need plants. If you east whole animals, livers and all, then I believe it possible to survive for an extended period. You won't be happy, but alive.
- Turing_Machine 10y ago
  The Bering Strait is only 53 miles/85 km wide, and the native peoples of Alaska and Siberia routinely crossed it in their indigenous boats (and over the ice, in winter). Also, there are plenty of plant foods available at the latitude of the Bering Strait. That doesn't really say anything one way or another about the premise of this article, but it's simply not true that a land bridge was required.
tzs 10y ago
A water route for the early migrants makes a lot of sense. There was a study published in "Nature" a couple months ago that looked at samples from sediments at choke points on the land routes, and determined that it took several hundred years after the routes opened for vegetation and then animals to appear [1]. During that several hundred years, migrating humans passing through would not be able to live off the land. They'd have to have brought their food with them. Note that this was before the invention of the wheel, so there would be no pulling your supplies with you on a cart. It was also before domestication of any animals other than dogs, so no pilling your supplies on a horse, or having a horse drag a sled. They also would not know how far they would have to go to get to some place that could support them, so would have no idea how much food to take. With the limitation of only being able to take what they could carry, or get dogs to carry, or get dogs to pull on sleds, I doubt that they would have enough to make it through. It's only after the plants and animals get well established, so that you can live off the land, that it becomes reasonably feasible to migrate that way. The Clovis culture was well established long before that, so they had to come some other way, A water route avoids these problems. First, you can carry a lot more with you when you go by boat. You can either make your boat bigger to have room for your supplies, or you can tow a supply boat or raft. (Ropes had been invented by then). Second, you can fish. I don't think the technology of the time would have caught much in the open ocean [2], but if they stayed reasonably close to coastlines they should have been able to catch plenty of fish. (Following coastlines might also be a good idea so they could go ashore now and then to try to find fresh water). What I don't think I've ever seen discussed is when did anyone go the other way? Presumably at some point someone came back and so people in Asia became aware that those who headed east and were never heard from again weren't all starving to death or sailing [3] off the edge of the world or whatever. [1] Here's an article about the study: http://www.history.com/news/new-study-refutes-theory-of-how-humans-populated-north-america http://www.history.com/news/new-study-refutes-theory-of-how-... [2] the open ocean is sometimes described as a "biological desert" because of the sparseness of life there, especially life reasonably near the surface (and so where ancient fisherman could reasonably have a shot at catching it). The overwhelming majority of ocean life is in the shallow seas above the continental shelfs. [3] well...rowing. This was before sails were invented.
- sandworm101 10y ago
ralfd 10y ago
> The Inuit/Eskimo peoples are and were perfectly capable of moving and living on water Suprisingly the Inuit are a very young culture! They started around 1000 AD in Alaska and had settled northern Canada and Greenland only when Europe discovered America. https://upload.wikimedia.org/wikipedia/commons/3/32/Arctic_cultures_900-1500.png https://upload.wikimedia.org/wikipedia/commons/3/32/Arctic_c... The Paleo-Eskimos (genetic studies show no connection to the Inuits, so no intermarriage) developed 2500 BC (and ended 1500 AD), so only 4000 years ago, this is way after the migration of Paleo-Indians into the American continent (40,000–16,500 years ago).
- sandworm101 10y ago
  I didn't mean to say that they were the culture that made the crossing. They are proof that the move was possible using only the resources available at the time.
- Turing_Machine 10y ago
  Yes, the Dorset culture was basically genocided by the Inuit. The Inuit actually still have stories about it.
  - Turing_Machine 10y ago
    Apparently someone doesn't like the word "genocide" here. The Dorset were wiped out so thoroughly by the encroaching proto-Inuit that they didn't even leave any genes behind. What would you call it?

205guy 10y ago

I can't believe there is only one (other) top-level comment in this thread, and it's basically anti-science. It doesn't matter what you "subscribe" to, what matters are theories backed by scientifically collected data.

MichaelBurge 10y ago
Is history generally considered a science? It would be weird to me for someone to use the scientific method to show that even Abraham Lincoln existed. That's not to say that history isn't a form of knowledge. There's more to knowledge than science.
- jschwartzi 10y ago
  That's because there's a wealth of documentary evidence showing the Lincoln existed within the past 200 years. Imagine if you were 10,000 years in the future. The United States has ceased to exist, and many of our monuments are buried in mud and rubble. The paper artifacts have mostly rotted away, or they lie buried in some preserving medium. No first-hand accounts remain from the period. One day, a team uncovers a partial statue of a seated man with a great beard. Was he a god, or an emperor of the land? How could they prove either stance without applying scientific techniques, gathering evidence from the remains of the surrounding buildings and analyzing it? Archeology may not be a hard science, but it is an empirical science.
  - DanielBMarkham 10y ago
    I love archaeology. I love evolutionary science. I love anthropology. I'm not replying to you directly here. I have a concern about this thread. I felt this was the best place to put it. Your use of the word "empirical" here may be accurate yet misleading. Some sciences work with hard data, falsifiable hypothesis, repoducibility, and so forth. In these we can construct mathematical models which eventually we trust explicitly. (Note that in most cases these are not explanatory models, simply sufficient ones.) Some sciences work with simple observation and correlation, with lots of imaginative community input in place to suppose causation. We can use mathematical models here as well, but there's a huge degree of noise here. I have no problem with a forum participant coming up with their own speculation. If folks don't like it they can ignore it. Perhaps one day evidence turns up which validates that speculation. We don't shut down those folks by calling them anti-science. Hell, give these people a book contract. The more imaginative narratives you can create from existing data, the more the scientific community at large will expand what they consider to be the world of alternatives to consider. What I'm seeing a lot of lately is taking anything with the label "science" on it and telling laymen that they have no business bullshitting in this area. This is not in the best interest of either science or the academy. ADD: I've seen the flip side of this as well, where really good scientists come up with the most wondrous and dramatic narratives about things where the evidence is thin. That's cool, but many of these folks will use the term "science" as a way of pumping up their speculative fiction. Stringing together a series of what most experts believe is likely while adding your own color commentary is not science. It's entertaining as hell and I love reading it. But it ain't science.

dzdt 10y ago

The map is interesting. I never knew the Aleutian Islands marked a former continental coastline.