Humans in America '115,000 years earlier than thought'

Humans in America '115,000 years earlier than thought'
A concentration of fossil bone and rock. The unusual positions of the femur heads, one up and one down, broken in the same manner next to each other is unusual. Mastodon molars are located in the lower right hand corner next to a large rock comprised of andesite which is in contact with a broken vertebra. Upper left is a rib angled upwards resting on a granitic pegmatite rock fragment. Credit: San Diego Natural History Museum

High-tech dating of mastodon remains found in southern California has shattered the timeline of human migration to America, pushing the presence of hominins back to 130,000 years ago rather than just 15,000 years, researchers said Wednesday.

Teeth and bones of the elephant-like creature unmistakably modified by human hands, along with stone hammers and anvils, leave no doubt that some species of early human feasted on its carcass, they reported in the journal Nature.

Discovered in 1992 during construction work to expand an expressway, the bone fragments "show clear signs of having been deliberately broken by humans with manual dexterity," said lead author Steve Holen, director of research at the Center for American Paleolithic Research.

Up to now, the earliest confirmed passage of our ancestors into North America took place about 15,000 years ago. These were modern humans—Homo sapiens—that probably crossed from Siberia into what is today Alaska, by land or along the coast.

There have been several other claims of an even earlier bipedal footprint on the continent, but none would take that timeline back further than 50,000 years, and all remain sharply contested.

The absence of human remains at the California site throws wide open the question of who these mysterious hunters were, as well as when—and how—they arrived on American shores.

A genetic link

One possibility that can be excluded with high confidence is that they were like us. Homo sapiens, experts say, did not exit Africa until about 80,000 to 100,000 years ago.

But that still leaves a wide range of candidates, including several other hominin species that roamed Eurasia 130,000 years ago, the authors said.

They include Homo erectus, whose earliest traces date back nearly two million years; Neanderthals, who fought and co-mingled with modern humans across Europe before dying out some 40,000 years ago; and an enigmatic species called Denisovans, whose DNA survives today in Australian aboriginals.

Dr. Steve Holen, director of research at the Center for American Paleolithic Research, and Adam Thomas, an undergraduate student of Steve’s, experimenting on how bones break under percussion using stones as hammers and anvils. The bone used for the experiment is a leg bone of a recently deceased modern elephant (died of natural causes), a mastodon relative. Video was shot in Tanzania. Credit: Kathleen Holen, co-director, Center for American Paleolithic Research

In a companion analysis, Holen and his team argue that—despite rising seas 130,000 years ago due to an inter-glacial period of warming—the overseas distances to the Americas were within the capacity of human populations at the time.

Intriguingly, in light of the new find, recent studies have also shown a genetic link between present-day Amazonian native Americans and some Asian and Australian peoples.

The picture that emerges "indicates a diverse set of founding populations of the Americas," said Erella Hovers, an anthropologist at Hebrew University of Jerusalem, who did not take part in the new study.

As for the early humans who carved up the bones at the Cerutti Mastodon site in San Diego, named for the paleontologist who discovered it, they likely died out, leaving no genetic trace in modern North Americans, the authors conjectured.

Credit: Dr. Tom Deméré, curator of paleontology and director of PaleoServices, San Diego Natural History Museum

Previous attempts to accurately date artefacts at the site fell short.

Then, in 2014, co-author James Paces, a researcher with the US Geological Survey, used state-of-the-art radiometric methods to measure traces of natural uranium and its decaying by-products in the mastodon bones, which were still fresh when broken by precise blows from stone hammers.

Not-so-new New World

The prehistoric butchery, he determined, took place 130,000 years ago, give or take 9,400 years, and was may have sought to extract nutritious marrow.

Humans in America '115,000 years earlier than thought'
Unbroken mastodon ribs and vertebrae, including one vertebra with a large well preserved neural spine found in excavation unit J4. Credit: San Diego Natural History Museum

"Since the original discovery, dating technology has advanced to enable us to confirm with further certainty that were here signficantly earlier than commonly accepted," said co-author Thomas Demere, a paleontologist at the San Diego Natural History Museum.

To strengthen the case, researchers set up an experiment to reproduce the stone-age food prep tableau unearthed from "Bed E" of the excavation site.

Using stone hammers and anvils similar to those found, they broke open large elephant bones much in the way pre-historic humans might have done. Certain blows yielded exactly the kind of strike marks, on both the hammers and the bones.

The same patterns, further tests showed, could not have emerged from natural wear-and-tear, or from the deliberate crafting of the tools, called flaking.

Humans in America '115,000 years earlier than thought'
Mastodon skeleton schematic showing which bones and teeth of the animal were found at the site. Credit: Dan Fisher and Adam Rountrey, University of Michigan

"This is a very old technology," said Holen. "We have people in Africa 1.5 million years ago breaking up elephant limb bones in this pattern, and as humans moved out of Africa and across the world they took this type of technology with them."

There remain nonetheless big holes in the narrative of to the Americas, Hovers said, commenting in Nature.

"Time will tell whether this evidence will bring a paradigm change in our understanding of hominin dispersal and colonisation throughout the world, including in what now seems to be a not-so-new New World," she wrote.

Explore further

Tunisian remains prove 100,000-year human presence

More information: Steven R. Holen et al. A 130,000-year-old archaeological site in southern California, USA, Nature (2017). DOI: 10.1038/nature22065
Journal information: Nature

© 2017 AFP

Citation: Humans in America '115,000 years earlier than thought' (2017, April 26) retrieved 18 October 2019 from
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User comments

Apr 26, 2017
The native American indians were not the first here but they drove the original inhabitants to extinction. Sound familiar? I wonder, if the not so native Americans want to give the land back to those they took it from.

Apr 26, 2017
Man there's nowhere in the world one can escape speculation land.

That ended for science as soon as money got involved.

Apr 26, 2017
The native American indians were not the first here but they drove the original inhabitants to extinction.

Of course not. Today's natives didn't show up till 115,000 years later.

Apr 26, 2017
The native American indians were not the first here but they drove the original inhabitants to extinction. Sound familiar? I wonder, if the not so native Americans want to give the land back to those they took it from.

Lack of fossils possibly indicates any early arrivals died out before the proto-indians made the trek.

Apr 26, 2017
I'm sure the researchers thought of this, but couldn't of this have been simply a mastodon that died and was later found 100 thousand later by an Indian and then modified, then found again by modern archeologists?

But I guess if you can find food and just keep walking, a person can get anywhere on this planet in a couple of decades, maybe its just a numbers game

Apr 26, 2017
There is surely no baseless assertion that will escape the loose grasp of your political agenda. Why do you bother commenting in a science site where you're always wrong, except when you're so out of your depth that you're not even wrong? What are you getting out of it?

The native American indians

Apr 26, 2017
Calico early man site, near Barstow CA. Fair amount of controversy, but interesting.

Apr 26, 2017
There were no knap stone tools found at this site. When hominids gathered to butcher an animal, the rocks would had been hit against one another to detach flakes, a process called knapping. Knap stones were found in Kenya dating to 3 million years so that these tools predated humans; the lack of knap stones suggests that the conclusion the authors are trying to make is suspect.

Apr 26, 2017
Some people think of the American Indians as 1 people. They were not. There were many tribes, many languages, and they were constantly battling each other and taking over others' lands. Over thousands of years. There is no clear truly first occupant of America.

Apr 26, 2017
The genocide perpetrated by the white devils currently in America was the deliberate extermination of an entire people for profit by an industrial civilisation. The ongoing pathetic attempts to whitewash genocide by people with tiny penis's just shows how morally bankrupt and imbecilic Trumpland has become.

Apr 26, 2017

Better read up on the DNA research on "Indians". Kennewick Man, Anzic Child, Spirit Lake mummy, Naia all have been tested and the DNA shows continuity from them to contemporary "Indians". Kennewick Man 's DNA was traced directly to livening members of the Colville & Yakama. DNA has
proven a single group entered and populated North and South America around 16,000 years ago.

Apr 27, 2017
I'm surprised that the editors and responses I read are not aware of the Darwin Early Man Site east of Barstow, CA.

Apr 27, 2017
Are the progs, leftist anthropoligists and native Americans going to kill this the way they did Kennewick Man?

Apr 27, 2017
I'm surprised that the editors and responses I read are not aware of the Darwin Early Man Site east of Barstow, CA.
You mean Calico Early Man Site and the general consensus is that geofacts were confused as artifacts. And one of the previous responses did mention it.

Apr 28, 2017
Well I'm enjoying the racist rants from different ideologues. And as much as I enjoy a flame war, I'm going to spoil your fun with an offer of some reasoned speculation instead.

If, the (no, it's not confirmed) hypothesized dating of the mammoth bones is proven correct? Occam's Razor, mostly likely the animal was killed by a flash-flood and buried beyond reach of large scavengers.

Over a hundred thousand years, the bones would have been uncovered and reburied by a multitude of seasonal flooding. It is a necessary burden on scientists to avoid 'Seeing faces in the clouds'.

Cause where are the Hominid teeth marks on those specific bones? Or for that matter, relics of a cooking fire?

Also, if it can be proven, beyond a reasonable doubt, that hominids were, if not established, wandering around North America at that time?

From that period, they would be Homo Erectus not our modern Homo Anthropophagus ancestors.

Yeah, we ate all the competition. Hooray for our team!

Jun 24, 2017
Concerning the reasoned speculation of rrwillsj:
. The article mentions mastodon, not mammoth bones.
. Your application of 'Occam's Razor' seems specious. I gather it derives from the usual circular logic: since it is impossible for hominids to have discovered the Americas before some Asians crossed a land bridge some 14 or 15K years ago, therefore any such appearance must derive from other causes, however otherwise less probable. Ales Hrdlicka would be proud. Also, you should research Occam's Razor.
. I guess you suppose any such putative hominids would have to be so primitive they would strip bones with their (presumably large and sharp) teeth. This in spite of the presence of stone tools, which would of course have to be geologic artifacts anyway. Weathering works in mysterious ways.
. Cooking fire not present? No evidence noted for a loo, either. Couldn't have been hominids.
. At least three other sites previously discovered, incl Calico Hills.

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