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bluefish cave bone

bluefish cave bone

 

Original Article:

westerndigs.org

by Blake de Pastino

A close look at bones found in a Yukon cave seems to confirm a controversial finding made decades ago, archaeologists say: that humans arrived in North America 10,000 years earlier than many experts believe.

The bones are the remains of horse, bison, mammoths, and other Ice Age fauna, originally excavated from the Bluefish Caves near the border of Alaska and the Yukon Territory in the 1970s and 1980s.

Back then, radiocarbon dating placed the bones at about 25, 000 years old — not in itself surprising, except that many of the bones appeared to have been butchered by humans.

And the earliest evidence of human activity on the continent — at least at the time — dated back a mere 14,000 years.

Anthropologist Lauriane Bourgeon at the University of Montreal has devoted her doctoral thesis to revisiting the controversy surrounding the Bluefish Caves bones.

And she has concluded that more than a dozen of the animal bones do indeed bear “indisputable evidence of butchery activity,” showing that humans were on the continent well before the end of the last Ice Age.

The implications of these findings are weighty, not only for the timing of the peopling of the Americas, but for the way in which people actually moved from Asia into what’s known as Eastern Beringia — the swath of North America immediately east of the Bering Strait.

Bluefish Caves are located near the Ogilvie Mountains in Yukon Territory. (Photo courtesy Lauriane Bourgeon)

Bluefish Caves are located near the Ogilvie Mountains in Yukon Territory. (Photo courtesy Lauriane Bourgeon)

“In addition to proving that Bluefish Caves is the oldest known archaeological site in North America,” Bourgeon and her colleagues write in the journal PLOS One, “the results offer archaeological support for the ‘Beringian standstill hypothesis,’ which proposes that a genetically isolated human population persisted in Beringia during the Last Glacial Maximum (ed: the Ice Age) and dispersed from there to North and South America.”

The caves were first excavated by Canadian archaeologist Jacques Cinq-Mars starting in 1977, who posited, based on radiocarbon dating at the time, that the scored and damaged animal bones were evidence of human activity in the Americas as much as 25,000 years ago.

Largely dismissed and later overlooked, the theory was recently taken up by Bourgeon.

In 2015, she published some of her preliminary findings, after having studied 5,600 bone fragments from Cave 2 of the Bluefish Caves.

Most of the scoring and hatching marks on the bones were made by scavenging animals and not humans, she said.

But at least two of the bones did betray the tell-tale signs of human butchery, she said, including the pelvis bone of a caribou that bore deep, parallel lines etched in them.

“That is typically the mark of a stone tool used to de-flesh or disarticulate a carcass,” she told Western Digs at the time.

But the oldest of the samples that she tested was no more than 14,000 years old.

(See full coverage of her 2015 study: “Butchered Bones Found in Yukon Cave Bear Marks of Early Americans, Study Finds“)

Today, she and her team have obtained even more impressive results.

Bourgeon’s full study covered 36,000 bones from Caves 1 and 2, studying them under a high-power microscope and comparing them to other bones that had been scarred by animals, broken by freeze-thaw cycles, or damaged by rockfall or other natural sources of abrasion.

She and her team concluded that 15 bone samples bore striations that they say are “confidently attributable to human activities.”

Unlike carnivore teeth, which leave wide, shallow, U-shaped depressions, these samples bore the signature of a hand-held tool, they assert.

“Series of straight, V-shaped lines on the surface of the bones were made by stone tools used to skin animals,” said Montreal’s Dr. Ariane Burke, adviser to Bourgeon and a co-author of the new study, in a press statement.

“These are indisputable cut-marks created by humans.”

The team also conducted its own series of radiocarbon tests on six of the bones with the butchery marks.

The youngest specimen was 12,000 years old and the oldest — the lower jaw of an extinct horse, said to have marks showing where its tongue was cut out — was 24,000 years old.

Taken together, these two data points suggest that Ice Age Alaska and Yukon were not only inhabited, the team asserts, but that it was inhabited by a genetically isolated population, because 24,000 years ago, the rest of the continent was covered in glaciers and impassable.

This idea — known as the Beringia standstill hypothesis — has been proposed by some geneticists, who have found molecular clues in the DNA of indigenous groups both east and west of the Bering Strait which suggest that the Americas’ earliest settlers lingered in Eastern Beringia for thousands of years before being able to migrate south.

“Our discovery confirms the ‘Beringian standstill hypothesis,’” said Burke in the statement.

“Genetic isolation would have corresponded to geographical isolation.

“During the Last Glacial Maximum, Beringia was isolated from the rest of North America by glaciers and steppes too inhospitable for human occupation to the West.

“It was potentially a place of refuge.”

A growing body of evidence has been discovered since the ‘70s that shows a substantial human presence in the Americas before 14,000 years ago.

But there’s limited archaeological evidence to suggest that the continent was populated a full 25,000 years ago.

To that, Bourgeon and her team say, future research must focus on both archaeological and genetic evidence, specifically in the region around the Bering Strait, in order to get to the bottom of how and when the continent was populated.

“More research effort is required in Beringia clearly, to substantiate the existence of a standstill population and fully understand the prehistory of the first people of the Americas,” they write.

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Original Article:

popular-archaeology.com

 

PLOS ONE—When fluctuating climates in the Ice Age altered habitats, modern humans may have adapted their diets in a different way than Neandertals, according to a study published April 27, 2016 in the open-access journal PLOS ONE by Sireen El Zaatari of the University of Tübingen, Germany, and colleagues.

The Neandertal lineage survived for hundreds of thousands of years despite the severe temperature fluctuations of the Ice Age. The reasons for their decline around 40 thousand years ago remain unclear. The authors of this study investigated the possible influence of dietary strategies using the fossilized molars of 52 Neandertals and Upper Paleolithic Homo sapiens (modern humans). They analysed the type and degree of microwear on the teeth to attempt to draw conclusions about diet type and to establish a relationship with prevalent climactic conditions.

They found that as the climate fluctuated and habitats altered, Neandertals may have adapted their diet to the resources that were most readily available, eating mainly meat when in open, cold steppe environments, and supplementing their diet with more plants, seeds, and nuts when in forested landscapes. Meanwhile, modern humans seemed to stick to their dietary strategy regardless of slight environmental changes and retained a relatively large proportion of plant-based foods in their diet. “To be able to do this, they may have developed tools to extract dietary resources from their environment”” says Sireen El Zaatari. The researchers concluded that Upper Paleolithic modern humans’ differing dietary strategies may have given them an advantage over the Neandertals.

The Neandertals may have maintained their opportunistic approach of eating whatever was available in their changing habitats over hundreds of thousands of years. However, modern humans seem to have invested more effort in accessing food resources and significantly changed their dietary strategies over a much shorter period of time, in conjunction with their development of tools, which may have given them an advantage over Neanderthals.

The European Neandertal and modern human individuals analysed in this study do not temporally overlap and thus would not inform us about direct dietary competition between these two groups. Nevertheless, if the behavioral differences detected in this study were already established at the time of contact between them, these differences might have contributed to the demise of the Neandertals and the survival of modern humans.

Source: PLOS ONE press release.

___________________________________________________

*El Zaatari S, Grine FE, Ungar PS, Hublin J-J (2016) Neandertal versus Modern Human Dietary Responses to Climatic Fluctuations. PLoS ONE 11(4): e0153277. doi:10.1371/journal.pone.0153277

his is an image of a fossilized human molar used in the study of dietary habits of Neandertals and Upper Paleolithic Homo sapiens. Credit: Sireen El Zaatari

his is an image of a fossilized human molar used in the study of dietary habits of Neandertals and Upper Paleolithic Homo sapiens. Credit: Sireen El Zaatari

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2007799020

 

Original Article:

By Ruth Schuster
haaretz.com

They ate plants too but Neanderthals subsisted on animals, leading to liver and kidney enlargement and wider thoraxes, say Tel Aviv University archaeologists.

Neanderthals and humans were kissing cousins, literally, but they had their anatomical differences, among them wider pelvises and rib-cages. Now archaeologists from Tel Aviv University suggest that the reason for these anatomical discrepancies is that Neanderthals ate mostly meat, while Homo sapiens has had a more variegated diet.

It isn’t new that the Neaderthal ribcage and pelvis are wider than man’s. But until now scientists had assumed that had to do with Neanderthals having greater energetic demands than Homo sapiens. Whether or not that was a factor, the Tel Aviv archaeologists think the reason may have been more diet-oriented.

Studies of coprolites (fossil feces) have shown that Neanderthals, who lived among European and Middle Eastern humans until around 30,000-40,000 years ago, also ate plant matter. But a range of studies have shown the Neanderthal diet to be heavily biased towards protein – meat and fat. Chemical studies of their bones has indicated that a bigger proportion of their diet came from meat than cave bears found at the same sites; analysis of the isotopes in Neanderthal collagen shows their diet consisted mainly of herbivores, and megafauna, such as sloths, mammoths and prehistoric rhinoceroses, as well as plants.

In the frigid winters of the Ice Age, large animals may have flourished, but their fat content would have been reduced. A theoretical model created by the Israeli scientists predicts that during glacial winters, when carbohydrates weren’t available and fat was scarce, the Neanderthals needed to get more caloric intake meat, and evolved to better convert the protein into life-giving energy.

To contend with all that protein, their livers, which are responsible for protein metabolism, had to become larger. So their lower thoraxes did too.

The more protein is metabolized, the more toxins such as urea need removal from the body. As their protein metabolism increased, the Neanderthals needed more renal capacity – an enlarged bladder and kidneys – to get rid of the toxins, could, evolutionarily, be the reason why the Neanderthal pelvis is wider than ours.

“Given that high protein consumption is associated with larger liver and kidneys in animal models, it appears likely that the enlarged inferior section of the Neanderthals’ thorax and possibly, in part, also his wide pelvis, represented an adaptation to provide encasement for those enlarged organs,” write the scientists.

“Early indigenous Arctic populations who primarily ate meat also displayed enlarged livers and the tendency to drink a lot of water, a sign of increased renal activity,” Ben-Dor points out.

Why the Neanderthals eventually went extinct is not known. They also ate whatever herbivores they could catch, not only giant animals. But among the many theories is that their demise is related to the extinction of the megafauna, which disappeared just before they did, around 50,000 years ago. We don’t know precisely why the megafauna went extinct either but one postulation is that the climate changed in ways they found uncomfortable, and they were hunted to death. If so, that may have doomed the Neanderthals in their turn.

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