Humans adapted to Arctic life 10,000 years earlier than thought

[Reefa]

 

It’s a classic image of life in the ice age: a giant mammoth brought down by the sharp spears of a hunting party.

 

Now we’ve discovered a particular carcass – apparently killed and butchered with weapons – that is special. It was found in north-western Siberia and is 45,000 years old, which means that our species seems to have adapted to Arctic life 10,000 years earlier than we thought.

 

Together with a similarly ancient wolf bone with signs of weapon damage unearthed in eastern Siberia, this suggests humans were widespread in the region at the time.

 

They may have therefore had the opportunity to move even further east – into North America – long before 20,000 years ago, which is when we had thought people first reached the Americas.

 

 

“These finds open perspectives,” says Vladimir Pitulko at the Russian Academy of Sciences in St Petersburg, who led the team that studied the remains. “They are going to change the story of our spread across the planet.”

 

The mammoth carcass was excavated in 2012 from the eastern side of Yenisei Bay at a latitude of 72° north. Radiocarbon dating of one of its leg bones confirmed its antiquity.

 

Mammoth rib with injuries

 

The carcass carries injuries to its head, right tusk, left shoulder blade and ribs. Some are consistent with an attack with thrusting spears or similar weapons. There is also evidence that humans tried to remove long slivers of ivory from the tusk, probably to use as butchering tools.

 

Whodunnit?

 

However, no human remains were found with the carcass, so it’s not clear who killed the mammoth.

 

“Neanderthals or Denisovans could have dispatched the mammoth,” says Jon Erlandson at the University of Oregon in Eugene.

 

But Pitulko says the hunters were almost certainly Homo sapiens.

 

Although we know that Neanderthals could bring down mammoths – and were still present in Eurasia 45,000 years ago – there’s no evidence they ever made it above a latitude of 48° north, which is more than 2500 kilometres south of the mammoth site. “It is hard to expect [Neanderthals] to move that far north,” he says.

 

The research team also unearthed the wolf leg bone, from a site called Bunge-Toll at a latitude of 68° north in north-east Siberia. Careful analysis shows it carries evidence of a powerful, but non-lethal, puncture wound that could only have been made by a sharp ivory or bone weapon.

 

Wolf leg bone with evidence of human-inflicted damage

 

That places humans within a few thousand kilometres of North America much earlier than we thought.

 

The consensus view is that humans arrived in eastern Siberia thousands of years later, and ultimately reached North America between 20,000 and 15,000 years ago.

This was around the height of the last ice age, when so much ocean water was locked up in ice that a land bridge opened up in the Bering Strait between Siberia and Alaska.

 

Crossing the bridge

 

But if the first eastern Siberians date back at least 45,000 years, they might have crossed into North America long before the 20,000 year mark, says Pitulko, given that the Bering land bridge probably existed at earlier points in the ice age.

 

It’s interesting work, says Eske Willerslev at the University of Copenhagen, Denmark.

 

But he is sceptical that the Americas were populated so early. His team’s previous work dated the divergence time between Native Americans and Siberians using full genomes.

 

“We got a maximum date for a split of 23,000 years,” he says. “This is consistent with well-established archaeological evidence showing occupation no earlier than 18,000 years ago.”

 

Pitulko agrees there isn’t yet any strong archaeological evidence that humans were present in North America earlier than 18,000 years ago – but that doesn’t rule out the possibility that such evidence will, eventually, come to light.

 

Willerslev also thinks it’s wise to retain an open mind. “One should never say never,” he says.

https://www.newscientist.com/article/dn28774-humans-adapted-to-arctic-life-10000-years-earlier-than-thought/