Migrants Across the Land Bridge

Ever since Europeans arrived in the Western Hemisphere they wondered about the origins of these people native to the Americans. It is now generally accepted that Homo sapiensoriginated in Africa. I know that may be disturbing to certain white supremacists in the United States. I remember when I was in Africa a few years ago, at a cave in the place they specifically call the “Cradle of Humanity,” indicating that this is believed to be the origin of the human race, I mentioned to one of our group exploring the cave that I guess this means are original ancestors were black. The idea shocked and disturbed him.

Eventually those Africans spread out around the world to Europe, Australia, Asia, and from there, the western hemisphere. It is an incredible story.

Amazingly there was a 16thcentury Jesuit missionary who reached some conclusions about these indigenous people of North America that really astounds. More than 400 years ago, in 1589,        Joséde Acosta suggested that American Indigenous people shared a Siberian homeland. He believed that small groups of hunters driven by near starvation might have followed now extinct animals across Asia into the Americas millennia before the Spaniards arrived in the Caribbean in 1492. He even suggested that such a journey would require “only short stretches of navigation.” This is an incredible insight when you remember that in 1589 it would actually take Europeans another 136 years to “discover” the Bering Strait. From time to time in this blog I have suggested that Europeans were not as smart as they thought they were. This was not one of those times! This guy was smart. As David Hurst Thomas said, “Contemporary science supports Acosta’s theory more or less.”

It does now seem clear to most scientists that the first Americans came to North America from Asia during the last Ice Age. Because no fossils have been found in North America of archaic human ancestors such as Neanderthals this suggests that anatomically modern humans first populated the western hemisphere.

There are some substantial doubts about when exactly the first humans got here, but it seems likely that it was about 35,000 years ago, though some say much less such as 13,000 years ago. The jury is still out.

No matter which dates one accepts, it is clear that humans came here during very difficult times. During the last Ice Age one-third of the earth and almost all of what we now call Canada was buried under massive continental ice sheets. In places the ice was 2 miles thick.  Ever time I think of that I am amazed. It is difficult to think that where I now live in Manitoba 2 mile thick ice covered all of the land. So much ice was locked up in these ice sheets that the world’s ocean levels dropped dramatically.

What the retreating waters revealed is what scientists now call Beringia—an enormous unglaciated piece of land known as the Bering Land Bridge.This connected Siberia to Alaska.

There is no certainty about how and when humans arrived in North America.  According to Olive Patricia Dickson and William Newbigging, in their book A Concise History of Canada’s First Nations:

“From physical and linguistic evidence, we know that humans were present in the Americas at least by 17,000 BP (before present) and perhaps by 50,000 BP or even earlier… Today it is widely accepted that at several periods during the late Pleistocene geological age, a land bridge connected Asia and North America and that some Amerindians crossed from the Old World to the New on foot during these times.  The first identifiable bridge dates back to about 75,000 years ago.  The last one ended about 14,000 years ago. Beringia, as this land bridge is called by scientists, at one point was more than 2,000 kilometres wide, more like a continent than a bridge.Once believed to have been a grassy and often boggy plain, recent studies have revealed that it was covered with birch, heath, and shrub willow, food for such animals as mammoth, mastodon, giant bison, and saiga antelope—and the predators that preyed on them. That human hunters followed the herds is a reasonable assumption.  These newcomers travelled mainly from north to south, either along the coast or further inland.  Some looped south of the glaciers, then headed north again as the ice retreated.”

They did not explore the north first because it was covered in ice!

Others suggest that Beringia was not quite that large. They suggest it was basically up to 1,000 km. (620mi.) wide at its greatest extent. The area was roughly as large as British Columbia and Alberta put together, some 1,600,000 sq. km. (620,000 sq. mi.).  Today there are only a few islands visible. No matter which figures are right, this area was huge.

Beringia like most of Siberia and all of North and North East China was not glaciated because snowfall was very light. It was a grassland steppe. The land bridge extended for hundred of kms into the continents on either side. Others have suggested what seems impossible that they travelled over the ice sheets. Either theory is incredible.

Many scientists believe that a small human population of at most a few thousand people first arrived in Beringia from Eastern Siberia during the Last Glacial Maximum. Others followed later. These people used Beringia as a platform to explore and settle North America. After that they expanded their settlement of the Americas sometime after 16,500 years ago when the massive continental glaciers started to recede and the ocean levels started to rise. After about 11,000 years before the present the bridge was covered again. It was no longer possible to walk back over land. Those who came to the western hemisphere were stuck here. Some scientists believe that before European colonization Yupik peoples lived on both sides of Beringia.

These theories, at once controversial, have now been bolstered by genetic evidence. That genetic evidence suggests that the ancestors of ancient native North Americans came from somewhere in Asia. Admittedly no one is sure exactly where these people came from.  No traces of humans have been found in Beringia leading some to cast doubt on the theory. So the question of where the ancient homeland of the first peoples of the Americas is still a live question.

For a century, Russians have been finding ancient skulls across Siberia. With those bones scientists have constructed genomes from both sides of Beringia. According to Niobe Thompson, speaking in a fascinating television series The Great Human Odyssey, “research has confirmed what we have long suspected, that the ancient home of the First North Americans was in Siberia.”

What is absolutely certain however is that these people from Asia were astonishing explorers. They even migrated into Europe.  All of this makes it very clear that humans, even ancient humans, were capable of more things than we ever thought possible. We have no choice but to respect our ancient ancestors. They were amazing people.

There is yet one more amazing human migration,  namely a migration into the Arctic. How could they do that? As Thompson said, “for a species born in Africa, the human adaptation to the Arctic was an impressive achievement and that adaptation was the key to the second half of the planet—the Americas…it was an Ice Age journey we once thought was impossible. Now we know humans found a way.” These were amazing people! And these were the original migrants to the Americas. All the others came much later and have much less legitimate claim to this hemisphere.

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