Scientists may have found an ancient route to America 24,000 years ago: ScienceAlert

The frozen highway may have given ancient travelers a clear route from Siberia to the New World more than 10,000 years before First Nations people arrived in America, it is thought.

According to data based on studies of sediments and fossilized marine life analyzed by researchers from the US Geological Survey, Woods Hole Oceanographic Institution, and Oregon State University, early migration would have been much easier due to sea ice.

A presentation by USGS geologist Summer Praetorius, at the annual meeting of the American Geophysical Union (AGU23) in San Francisco, suggests that flat expanses of winter ice may have played a crucial role in facilitating travel in times when traffic By boat is very dangerous.

For the better part For half a century, archaeologists generally considered a culture known as a “civilization.” Clovis people As the original pioneers of the North American continent. Attracted by the fertile new hunting grounds, families made journeys through them The lands are briefly exposed By retreating ice that connected Siberia to Alaska about 13,000 years ago.

There was a lot to this hypothesis. A handful of Skeletal remains And Extruded tips are similarly styled Finding them among the now-extinct megafauna was concrete evidence of their existence, while climate data supported a timeline of relatively easy movement between land masses.

However, a series of discoveries over recent decades have continued to erode confidence in the Clovis I hypothesis, delaying the arrival of humans in the Americas back to the last Ice Age more than 25,000 years ago.

One pressing question is how these ancient travelers made the arduous journey in the first place. While sea levels would likely have been low enough to expose a solid bridge across the top of the world long ago Nearly 36,000 years agoThe blanket of snow and rugged glaciers covering the landscape would have been a struggle, if it could have been crossed at all.

Once the glaciers began to retreat, a thin strip of coastal ecosystems would have provided communities with the resources and means of boat travel. A settlement 14 thousand years old On the west coast of Canada also supports the possibility that pre-Clovis people were slowly making their way along the water's edge.

The “kelp highway hypothesis” posits that marine technology was up to the task of transporting families safely thousands of kilometers across a frigid marine environment, a possibility that probably depended largely on when the journey was made.

according to Study published in 2020Windows of opportunity may have closed during critical warm periods, when accelerating melting would have sent currents swirling in the wrong direction for migrating paddlers as freshwater floods flowed into the ocean.

According to Pretorius and her team, climate model analysis confirms that strong winds and lower sea levels would have helped make ocean currents 20,000 years ago twice as strong as they are today, adding to the problems for any would-be sailors.

However, records also indicate that there were large areas of winter sea ice around 15,000 years ago, along which migrants would have walked, or even skied.

“We specify 24.5 – 22 [thousand years ago] And 16.4 – 14.8 [thousand years ago] As the most likely time periods to accommodate early migration along the Alaskan coast, possibly fueled by movement and residence on the “ice-sea highway,” The researchers write In their report.

This does not mean that sea travel should be excluded during periods favored by currents. It is also not strong evidence that such trips actually occurred.

In light of emerging signs that humans may have ventured as far south as New Mexico More than 20,000 years agoit can be assumed that there may have been a relatively safe and open path taken by their ancestors to make the Great Leap between worlds.

This research was presented in Annual Meeting of the American Geophysical Union In San Francisco on December 16.