Early humans moved into subarctic climates earlier than thought, study says
Excavations at Bacho Kiro Cave have unearthed new artifacts from the Middle Palaeolithic Neanderthal occupations, some of which have shown early humans moving through subarctic climates earlier than thought. Photo by Tsenka Tsanova/MPI-EVA
Sept. 22 (UPI) -- Humans have been living on all but one of Earth's continents for thousands of years, but exactly how Homo sapiens successfully dispersed across the planet remains an open question.
Most models suggest early humans relied on warmer climatic conditions to move into northern environs, but a new survey of archaeological materials suggests humans were enduring frigid conditions -- like those typical of present-day northern Scandinavia -- much earlier than previously thought.
According to the new research, published Wednesday in the journal Science Advances, early human populations were surprisingly adaptable and resilient.
"Using these new insights, new models of the spread of our species across Eurasia will now need to be constructed, taking into account their higher degree of climatic flexibility," study co-author Jean-Jacques Hublin, director of the Department of Human Evolution at the Max Planck Institute, said in a press release.
For the study, scientists focused on human habitation inside Bacho Kiro Cave, an important archaeological site in Bulgaria.
Researchers analyzed archaeological materials dating back thousands of years, including the remains of herbivores butchered by human occupants.
From these materials, scientists extracted paleoclimate data, which allowed researcher to produce a detailed record of what local climate conditions were like at the times when humans were occupying the cave.
The technique offers a better idea of the context of local climates, as opposed to more common correlations made between archaeological data and climatic archives from different locations, said study co-author Kate Britton.
"It really gives us insight into what life was like 'on the ground,'" said Britton, who is also a researcher at Max Planck Institute for Evolutionary Anthropology and the University of Aberdeen
Few archaeological sites can offer both evidence of human habitation and reliable paleoclimate data, making it difficult to do the kinds of analysis conducted since Bacho Kiro Cave.
RELATED Pioneering Homo sapiens produced earliest modern artifacts in Europe
"Due to the time consuming nature of the analysis and the reliance on the availability of particular animal remains, oxygen isotope studies or other ways of generating climatic data directly from archaeological sites remain scarce for the time period when Homo sapiens first spread across Eurasia," said lead study author Sarah Pederzani, who is also a researcher at the Max Planck and Aberdeen.
Pederzani spent a year drilling into the teeth of ancient animals recovered from the cave. Using stable isotope ratio mass spectrometry, researchers were able to precisely date the animals remains, as well as collect details about the local climate conditions.
"Through this time intensive analysis that included a total of 179 samples, it was possible to obtain a very highly resolved record of past temperatures, including summer, winter and mean annual temperature estimates for human occupations spanning more than 7,000 years," said Pederzani.
The latest analysis followed a multiyear effort to recover archaeological materials from Bacho Kiro Cave. Deposits from the cave's lowest portion yielded a variety of animal bones, stone tools, pendants and even human remains.
The artifacts suggest humans had begun spreading into southeastern Europe from the Levant as early as 45,000 years ago -- tolerating subarctic conditions as they moved into the region.
Excavations at Bacho Kiro Cave have unearthed new artifacts from the Middle Palaeolithic Neanderthal occupations, some of which have shown early humans moving through subarctic climates earlier than thought. Photo by Tsenka Tsanova/MPI-EVA
Sept. 22 (UPI) -- Humans have been living on all but one of Earth's continents for thousands of years, but exactly how Homo sapiens successfully dispersed across the planet remains an open question.
Most models suggest early humans relied on warmer climatic conditions to move into northern environs, but a new survey of archaeological materials suggests humans were enduring frigid conditions -- like those typical of present-day northern Scandinavia -- much earlier than previously thought.
According to the new research, published Wednesday in the journal Science Advances, early human populations were surprisingly adaptable and resilient.
"Using these new insights, new models of the spread of our species across Eurasia will now need to be constructed, taking into account their higher degree of climatic flexibility," study co-author Jean-Jacques Hublin, director of the Department of Human Evolution at the Max Planck Institute, said in a press release.
For the study, scientists focused on human habitation inside Bacho Kiro Cave, an important archaeological site in Bulgaria.
Researchers analyzed archaeological materials dating back thousands of years, including the remains of herbivores butchered by human occupants.
From these materials, scientists extracted paleoclimate data, which allowed researcher to produce a detailed record of what local climate conditions were like at the times when humans were occupying the cave.
The technique offers a better idea of the context of local climates, as opposed to more common correlations made between archaeological data and climatic archives from different locations, said study co-author Kate Britton.
"It really gives us insight into what life was like 'on the ground,'" said Britton, who is also a researcher at Max Planck Institute for Evolutionary Anthropology and the University of Aberdeen
Few archaeological sites can offer both evidence of human habitation and reliable paleoclimate data, making it difficult to do the kinds of analysis conducted since Bacho Kiro Cave.
RELATED Pioneering Homo sapiens produced earliest modern artifacts in Europe
"Due to the time consuming nature of the analysis and the reliance on the availability of particular animal remains, oxygen isotope studies or other ways of generating climatic data directly from archaeological sites remain scarce for the time period when Homo sapiens first spread across Eurasia," said lead study author Sarah Pederzani, who is also a researcher at the Max Planck and Aberdeen.
Pederzani spent a year drilling into the teeth of ancient animals recovered from the cave. Using stable isotope ratio mass spectrometry, researchers were able to precisely date the animals remains, as well as collect details about the local climate conditions.
"Through this time intensive analysis that included a total of 179 samples, it was possible to obtain a very highly resolved record of past temperatures, including summer, winter and mean annual temperature estimates for human occupations spanning more than 7,000 years," said Pederzani.
The latest analysis followed a multiyear effort to recover archaeological materials from Bacho Kiro Cave. Deposits from the cave's lowest portion yielded a variety of animal bones, stone tools, pendants and even human remains.
The artifacts suggest humans had begun spreading into southeastern Europe from the Levant as early as 45,000 years ago -- tolerating subarctic conditions as they moved into the region.
Issued on: 22/09/2021 -
People in the Marquesas islands are genetically close to the people of Easter Island nearly 4,000 kilometres away
GREGORY BOISSY AFP/File
Paris (AFP)
Easter Island's famous megaliths have relatives on islands thousands of miles to the north and west -- and so did the people who created them, a study said Wednesday.
Research showed that over a 250-year period separate groups of people set out from tiny islands east of Tahiti to settle Easter Island, the Marquesas and Raivavae -- archipelagos that are thousands of miles apart but all home to similar ancient statues.
"These statues are only on those islands that are closely connected genetically," the study's lead author Alexander Ioannidis of Stanford University told AFP.
Using cutting-edge analysis of modern DNA, Ioannidis and his team were able to map and date the first Polynesians' path of settlement, which began in Samoa and fanned out across the Pacific between the years 830 and 1360.
"This had been an open problem since Captain Cook first noticed that the people on the Polynesian islands were all speaking the same language," Ioannidis said.
The expansion happened rapidly -- over about 17 generations -- outpacing major changes in language or culture that could have served as markers, the findings show.
The researchers were able to piece together the puzzle of trans-Pacific migration by comparing the genetic material in 430 present-day inhabitants across 21 islands.
The outward expansion from Samoa unfolded westward to Fiji, Tonga in the south, and then to Raratonga in the east around the year 830.
- 'Small, ring-like islands' -
A few hundred years later, descendents on Raratonga travelled to settle present-day Tahiti and the Tuamotu archipelago just beyond.
It is from the small, long-overlooked sand-bar islands of Tuamotu that the most ambitious forays set out, Ioannidis said.
Now sparsely-populated thanks in part to their role as nuclear test grounds, the Tuamotus span an area equal to the distance between England and Greece.
The study notes that the low-lying islands likely emerged from below sea level only a few hundred years before Polynesians spread there.
Paris (AFP)
Easter Island's famous megaliths have relatives on islands thousands of miles to the north and west -- and so did the people who created them, a study said Wednesday.
Research showed that over a 250-year period separate groups of people set out from tiny islands east of Tahiti to settle Easter Island, the Marquesas and Raivavae -- archipelagos that are thousands of miles apart but all home to similar ancient statues.
"These statues are only on those islands that are closely connected genetically," the study's lead author Alexander Ioannidis of Stanford University told AFP.
Using cutting-edge analysis of modern DNA, Ioannidis and his team were able to map and date the first Polynesians' path of settlement, which began in Samoa and fanned out across the Pacific between the years 830 and 1360.
"This had been an open problem since Captain Cook first noticed that the people on the Polynesian islands were all speaking the same language," Ioannidis said.
The expansion happened rapidly -- over about 17 generations -- outpacing major changes in language or culture that could have served as markers, the findings show.
The researchers were able to piece together the puzzle of trans-Pacific migration by comparing the genetic material in 430 present-day inhabitants across 21 islands.
The outward expansion from Samoa unfolded westward to Fiji, Tonga in the south, and then to Raratonga in the east around the year 830.
- 'Small, ring-like islands' -
A few hundred years later, descendents on Raratonga travelled to settle present-day Tahiti and the Tuamotu archipelago just beyond.
It is from the small, long-overlooked sand-bar islands of Tuamotu that the most ambitious forays set out, Ioannidis said.
Now sparsely-populated thanks in part to their role as nuclear test grounds, the Tuamotus span an area equal to the distance between England and Greece.
The study notes that the low-lying islands likely emerged from below sea level only a few hundred years before Polynesians spread there.
Ancient Polynesians expanded to remote islands from the Tuamotu archipelago GREGORY BOISSY AFP/File
"They needed to have a maritime culture to get in between these small, ring-like islands," Ioannidis said.
"I think that explains in some part why it's from there that we see the longest-distance voyages going out."
This became ground zero for the megalith-building peoples who came to inhabit the Marquesas, Rapa Nui (Easter Island) and Raivavae.
The timing of those expansions fits with earlier DNA-based findings by Ioannidis and his team showing that Native Americans -- probably from the northwestern coast of South America -- and Polynesians mingled around the year 1200.
- Ancient clues in modern DNA -
"The date we found for that contact is very close to the dates we find for these voyages out from the Tuamotus to settle these remote islands," Ioannidis said.
Today's Polynesian populations have mixed heritage, with traces of Europe, Africa and other places in their ancestry.
While genetic studies of ancient peoples have tended to focus on ancient DNA samples unearthed from archaeological sites, Ioannidis said his team had been able to home in on telltale sequences buried in modern DNA.
They used a software to analyse samples from 430 inhabitants across 21 different islands to identify recurring gene patterns specific to Polynesians, blocking out DNA sequences associated with European or other ancestry.
Otherwise, "you would just find that the islands with the 'most Polynesian' DNA were more related," Ioannidis explained.
"They needed to have a maritime culture to get in between these small, ring-like islands," Ioannidis said.
"I think that explains in some part why it's from there that we see the longest-distance voyages going out."
This became ground zero for the megalith-building peoples who came to inhabit the Marquesas, Rapa Nui (Easter Island) and Raivavae.
The timing of those expansions fits with earlier DNA-based findings by Ioannidis and his team showing that Native Americans -- probably from the northwestern coast of South America -- and Polynesians mingled around the year 1200.
- Ancient clues in modern DNA -
"The date we found for that contact is very close to the dates we find for these voyages out from the Tuamotus to settle these remote islands," Ioannidis said.
Today's Polynesian populations have mixed heritage, with traces of Europe, Africa and other places in their ancestry.
While genetic studies of ancient peoples have tended to focus on ancient DNA samples unearthed from archaeological sites, Ioannidis said his team had been able to home in on telltale sequences buried in modern DNA.
They used a software to analyse samples from 430 inhabitants across 21 different islands to identify recurring gene patterns specific to Polynesians, blocking out DNA sequences associated with European or other ancestry.
Otherwise, "you would just find that the islands with the 'most Polynesian' DNA were more related," Ioannidis explained.
Map of Polynesia showing early eastward migration which began in the IX century
Cléa PÉCULIER AFP/File
"That's not interesting from a historical perspective."
His team used the genetic clues to draw a kind of family tree across the Pacific, east-to-west.
Since DNA strands shorten as they are re-combined over generations, the length of shared segments revealed how many generations passed between each settlement.
© 2021 AFP
"That's not interesting from a historical perspective."
His team used the genetic clues to draw a kind of family tree across the Pacific, east-to-west.
Since DNA strands shorten as they are re-combined over generations, the length of shared segments revealed how many generations passed between each settlement.
© 2021 AFP
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