Archaeologists discover oldest known bead in the Americas

University of Wyoming archaeology Professor Todd Surovell and his team of collaborators have discovered a tube-shaped bead made of bone that is about 12,940 years old.

The bead, found at the La Prele Mammoth site in Converse County, is the oldest known bead in the Americas.

Surovell's research was published in the peer-reviewed journal Scientific Reports; the paper is titled "Use of hare bone for the manufacture of a Clovis bead." Members of the research team included people from UW, the Office of the Wyoming State Archaeologist, the University of Manchester, Weber State University and Chico State University.

The La Prele Mammoth site preserves the remains of a killed or scavenged sub-adult Columbian mammoth and an associated camp occupied during the time the animal was butchered.

To determine the origin of the bone bead, the team extracted collagen for zooarchaeology by mass spectrometry, also known as ZooMS, which allowed the group to gain insights about the chemical composition of the bone.

The researchers concluded that the bead was made from either a metapodial (the bones that link the phalanges of the digits to the more proximal bones of the limb) or a proximal phalanx (a bone found in the fingers and toes of humans and other vertebrates) of a hare.

This finding represents the first secure evidence for the use of hares during the Clovis period, which refers to a prehistoric era in North America, particularly prominent about 12,000 years ago.

It's named after the Clovis archaeological site in New Mexico, where distinctive stone tools were discovered.

The bead is about 7 millimeters in length, and its internal diameter averages 1.6 millimeters.

The research team considered the possibility that the bead could have been the result of carnivore consumption and digestion and not created by humans; however, carnivores were not common on this site, and the artifact was recovered 1 meter from a dense scatter of other cultural materials.

Additionally, the grooves on the outside of the bead are consistent with creation by humans, either with stones or their teeth.

Beads like this one were likely used to decorate their bodies or clothing.

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A mixed origin made maize successful

Maize is one of the world's most widely grown crops. It is used for both human and animal foods and holds great cultural significance, especially for indigenous peoples in the Americas. Yet despite its importance, the origins of the grain have been hotly debated for more than a century. Now new research, published Dec. 1 in Science, shows that all modern maize descends from a hybrid created just over 5000 years ago in central Mexico, thousands of years after the plant was first domesticated.

The work has implications both for improving one of the world's most important crops and for understanding how the histories of people and their crops influence each other.

"It's a new model for the origins and spread of maize, and how it became a staple across the Americas," said Jeffrey Ross-Ibarra, professor in the Department of Evolution and Ecology at the University of California, Davis and senior author on the paper.

For the last few decades, the consensus has been that maize (Zea mays) was domesticated once from a single wild grass -- called teosinte -- in the lowlands of southwest Mexico about 9,000 to 10,000 years ago.

Known as corn in the United States, maize is not only a staple of diets around the globe, but also can be processed into sweeteners,ethanol fuel and other uses.

More recently, though, it's become clear that the genome of modern maize also contains a hefty dose of DNA from a second teosinte that grows in the highlands of central Mexico.

Ross-Ibarra and collaborators in the U. S., China and Mexico analyzed the genomes of over a thousand samples of maize and wild relatives.

They found that about 20 percent of the genome of all maize worldwide comes from this second highland teosinte.

New model for spread of maize

These new findings suggest that, though maize was domesticated around 10,000 years ago, it was not until 4,000 years later, when it hybridized with highland teosinte, that maize really took off as a popular crop and food staple.

This is also supported by archaeological evidence of the increasing importance of maize around the same time.

The new crop spread rapidly through the Americas and later worldwide.

Today, about 1.2 billion metric tons is harvested each year globally.

The hunt for why highland teosinte enabled maize to become a staple is still underway, Ross-Ibarra said.

The researchers did find genes related to cob size -- perhaps representing an increased yield potential -- and flowering time, which likely helped maize, a tropical crop, to grow at higher latitudes with longer days.

Hybridization may also have brought "hybrid vigor," where a hybrid organism is more vigorous than either of its parents.

The researchers observed that genomic segments from highland teosinte contained fewer harmful mutations than did other parts of the genome.

While the initial hybridization may have been accidental, it's likely that indigenous farmers recognized and took advantage of the novel variation introduced from highland maize, Ross-Ibarra said.

Even today, he said, "If you talk to Mexican farmers, some will tell you that letting wild maize grow near the fields makes their crops stronger."

A team led by Ross-Ibarra with Professor Graham Coop at UC Davis, archaeologists at UC Santa Barbara and geneticists at Swedish University of Agricultural Sciences was recently awarded a $1.6 million grant from the National Science Foundation to study the co-evolution of humans and maize in the Americas.

They will use genetics to look at how humans and maize spread across the continent and how populations of both maize and humans grew and shrank as they interacted with each other.

"We will incorporate human genetic data, maize genetics and archaeological data in an effort to answer many of the questions raised by our new model of maize origins," Ross-Ibarra said.

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Evidence of Ice Age human migrations from China to the Americas and Japan

Scientists have used mitochondrial DNA to trace a female lineage from northern coastal China to the Americas. By integrating contemporary and ancient mitochondrial DNA, the team found evidence of at least two migrations: one during the last ice age, and one during the subsequent melting period. Around the same time as the second migration, another branch of the same lineage migrated to Japan, which could explain Paleolithic archeological similarities between the Americas, China, and Japan. The study appears May 9 in the journal Cell Reports.

"The Asian ancestry of Native Americans is more complicated than previously indicated," says first author Yu-Chun Li, a molecular anthropologist at the Chinese Academy of Sciences. "In addition to previously described ancestral sources in Siberia, Australo-Melanesia, and Southeast Asia, we show that northern coastal China also contributed to the gene pool of Native Americans."

Though it was long assumed that Native Americans descended from Siberians who crossed over the Bering Strait's ephemeral land bridge, more recent genetic, geological, and archeological evidence suggests that multiple waves of humans journeyed to the Americas from various parts of Eurasia.

To shed light on the history of Native Americans in Asia, a team of researchers from the Chinese Academy of Sciences followed the trail of an ancestral lineage that might link East Asian Paleolithic-age populations to founding populations in Chile, Peru, Bolivia, Brazil, Ecuador, Mexico, and California. The lineage in question is present in mitochondrial DNA, which can be used to trace kinship through the female line.

The researchers scoured over 100,000 contemporary and 15,000 ancient DNA samples from across Eurasia to eventually identify 216 contemporary and 39 ancient individuals belonging to the rare lineage. By comparing the accumulated mutations, geographic locations, and carbon-dated age of each of these individuals, the researchers were able to trace the lineage's branching path. They identified two migration events from northern coastal China to the Americas, and in both cases, they think that the travelers probably set dock in America via the Pacific coast rather than by crossing the inland ice-free corridor (which would not have opened at the time).

The first radiation event occurred between 19,500 and 26,000 years ago during the Last Glacial Maximum, when ice sheet coverage was at its greatest and conditions in northern China were likely inhospitable for humans. The second radiation occurred during the subsequent deglaciation or melting period, between 19,000 and 11,500 years ago. There was a rapid increase in human populations at this time, probably due to the improved climate, which may have fueled expansion into other geographical regions.

The researchers also uncovered an unexpected genetic link between Native Americans and Japanese people. During the deglaciation period, another group branched out from northern coastal China and traveled to Japan. "We were surprised to find that this ancestral source also contributed to the Japanese gene pool, especially the indigenous Ainus," says Li.

This discovery helps to explain archeological similarities between the Paleolithic peoples of China, Japan, and the Americas. Specifically, the three regions share similarities in how they crafted stemmed projectile points for arrowheads and spears. "This suggests that the Pleistocene connection among the Americas, China, and Japan was not confined to culture but also to genetics," says senior author Qing-Peng Kong, an evolutionary geneticist at the Chinese Academy of Sciences.

Though the study focused on mitochondrial DNA, complementary evidence from Y chromosomal DNA suggests that male ancestors of Native Americans also lived in northern China at around the same time as these female ancestors.

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Archaeologists uncover oldest known projectile points in the Americas

Oregon State University archaeologists have uncovered projectile points in Idaho that are thousands of years older than any previously found in the Americas, helping to fill in the history of how early humans crafted and used stone weapons.

The 13 full and fragmentary projectile points, razor sharp and ranging from about half an inch to 2 inches long, are from roughly 15,700 years ago, according to carbon-14 dating. That's about 3,000 years older than the Clovis fluted points found throughout North America, and 2,300 years older than the points previously found at the same Cooper's Ferry site along the Salmon River in present-day Idaho.

The findings were published today in the journal Science Advances.

"From a scientific point of view, these discoveries add very important details about what the archaeological record of the earliest peoples of the Americas looks like," said Loren Davis, an anthropology professor at OSU and head of the group that found the points. "It's one thing to say, 'We think that people were here in the Americas 16,000 years ago;' it's another thing to measure it by finding well-made artifacts they left behind."

Previously, Davis and other researchers working the Cooper's Ferry site had found simple flakes and pieces of bone that indicated human presence about 16,000 years ago. But the discovery of projectile points reveals new insights into the way the first Americans expressed complex thoughts through technology at that time, Davis said.

The Salmon River site where the points were found is on traditional Nez Perce land, known to the tribe as the ancient village of Nipéhe. The land is currently held in public ownership by the federal Bureau of Land Management.

The points are revelatory not just in their age, but in their similarity to projectile points found in Hokkaido, Japan, dating to 16,000-20,000 years ago, Davis said. Their presence in Idaho adds more detail to the hypothesis that there are early genetic and cultural connections between the ice age peoples of Northeast Asia and North America.

"The earliest peoples of North America possessed cultural knowledge that they used to survive and thrive over time. Some of this knowledge can be seen in the way people made stone tools, such as the projectile points found at the Cooper's Ferry site," Davis said. "By comparing these points with other sites of the same age and older, we can infer the spatial extents of social networks where this technological knowledge was shared between peoples."

These slender projectile points are characterized by two distinct ends, one sharpened and one stemmed, as well as a symmetrical beveled shape if looked at head-on. They were likely attached to darts, rather than arrows or spears, and despite the small size, they were deadly weapons, Davis said.

"There's an assumption that early projectile points had to be big to kill large game; however, smaller projectile points mounted on darts will penetrate deeply and cause tremendous internal damage," he said. "You can hunt any animal we know about with weapons like these."

These discoveries add to the emerging picture of early human life in the Pacific Northwest, Davis said. "Finding a site where people made pits and stored complete and broken projectile points nearly 16,000 years ago gives us valuable details about the lives of our region's earliest inhabitants."

The newly discovered pits are part of the larger Cooper's Ferry record, where Davis and colleagues have previously reported a 14,200-year-old fire pit and a food-processing area containing the remains of an extinct horse. All told, they found and mapped more than 65,000 items, recording their locations to the millimeter for precise documentation.

The projectile points were uncovered over multiple summers between 2012 and 2017, with work supported by a funding partnership held between OSU and the BLM. All excavation work has been completed and the site is now covered. The BLM installed interpretive panels and a kiosk at the site to describe the work.

Read more at Science Daily

Europeans in the Americas 1000 years ago

Columbus was not the first European to reach the Americas. The Vikings got there centuries beforehand, although exactly when has remained unclear. Here, an international team of scientists show that Europeans were already active in the Americas in 1021 AD.

The Vikings sailed great distances in their iconic longships. To the west, they established settlements in Iceland, Greenland and eventually a base at L'Anse aux Meadows, Newfoundland, Canada. However, it has remained unclear when this first transatlantic activity took place. Here, scientists show that Europeans were present in the Americas in 1021 AD -- precisely 1000 years ago this year. This date also marks the earliest known point by which the Atlantic had been crossed, and migration by humankind had finally encircled the entire planet.

A Solar Storm Solution

In this study, the chopping of wood by Vikings at L'Anse aux Meadows was dated to exactly the year 1021 AD. The three pieces of wood studied, from three different trees, all came from contexts archaeologically attributable to the Vikings. Each one also displayed clear evidence of cutting and slicing by blades made of metal -- a material not produced by the indigenous population. The exact year was determinable because a massive solar storm occurred in 992 AD that produced a distinct radiocarbon signal in tree rings from the following year.

"The distinct uplift in radiocarbon production that occurred between 992 and 993 AD has been detected in tree-ring archives from all over the world" says Associate Professor Michael Dee (University of Groningen), director of the research. Each of the three wooden objects exhibited this signal 29 growth rings (years) before the bark edge. "Finding the signal from the solar storm 29 growth rings in from the bark allowed us to conclude that the cutting activity took place in the year 1021 AD" says Dr Margot Kuitems (University of Groningen), first author of the paper.

How Far, How Often?

The number of Viking expeditions to the Americas, and the duration of their stay over the Atlantic, remain unknown. All current data suggest that the whole endeavour was somewhat short lived, and the cultural and ecological legacy of this first European activity in the Americas is likely to have been small. Nonetheless, botanical evidence from L'Anse aux Meadows has confirmed that the Vikings did explore lands further south than Newfoundland.

The Sagas

1021 AD is the earliest year in which European presence in the Americas can be scientifically proven. Previous dates for the Viking presence in the Americas have relied heavily on the Icelandic Sagas. However, these began as oral histories and were only written down centuries after the events they describe. Whilst contradictory and at times fantastical, the Sagas also suggest encounters occurred, both violent and amiable, between the Europeans and the indigenous people of the region. However, little archaeological evidence has been uncovered to support such exchanges. Other medieval accounts also exist, which imply prominent figures on the European mainland were made aware the Vikings had made landfall across the Atlantic.

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Earliest evidence of human activity found in the Americas, researchers report

Footprints found at White Sands National Park in New Mexico provide the earliest unequivocal evidence of human activity in the Americas and provide insight into life over 23,000 years ago, scientists report.

The findings are described in an article in the journal Science.

Researchers Jeff Pigati and Kathleen Springer, with the U.S. Geological Survey, used radiocarbon dating of seed layers above and below the footprints to determine their age. The dates range in age and confirm human presence over at least two millennia, with the oldest tracks dating back 23,000 years.

This corresponds to the height of the last glacial cycle, during something known as the Last Glacial Maximum, and makes them the oldest known human footprints in the Americas.

It was previously thought that humans entered America much later, after the melting of the North American ice sheets, which opened up migration routes.

"Our dates on the seeds are tightly clustered and maintain stratigraphic order above and below multiple footprint horizons -- this was a remarkable outcome," Springer said.

The footprints tell an interesting tale of what life was like at this time. Judging by their size, the tracks were left mainly by teenagers and younger children, with the occasional adult.

"The footprints left at White Sands give a picture of what was taking place, teenagers interacting with younger children and adults," said lead study author Matthew Bennett from Bournemouth University in England. "We can think of our ancestors as quite functional, hunting and surviving, but what we see here is also activity of play, and of different ages coming together. A true insight into these early people."

"For decades, archaeologists have debated when people first arrived in the Americas," said co-author Vance Holliday, a professor in the UArizona School of Anthropology and Department of Geosciences. "Few archaeologists see reliable evidence for sites older than about 16,000 years. Some think the arrival was later, no more than 13,000 years ago by makers of artifacts called Clovis points. The White Sands tracks provide a much earlier date. There are multiple layers of well-dated human tracks in streambeds where water flowed into an ancient lake. This was 10,000 years before Clovis people."

Holliday and study co-author Brendan Fenerty, a UArizona doctoral student in the Department of Geosciences, documented basic geologic layering and dating in trenches on the White Sands Missile Range near the discovery site several years before the tracks were found.

"We were interested in reconstructing the evolution of the landscape in the context of environmental changes and some younger archaeological sites in the area," Holliday said. "We had no idea what was buried nearby."

Tracks of mammoth, giant ground sloth, dire wolves and birds are also all present at the White Sands site.

"It is an important site because all of the trackways we've found there show an interaction of humans in the landscape alongside extinct animals, like mammoths and giant sloths," said study co-author Sally Reynolds of Bournemouth University. "We can see the co-existence between humans and animals on the site as a whole, and by being able to accurately date these footprints, we're building a greater picture of the landscape."

The human tracks at White Sands were first discovered by David Bustos, resources manager at the park.

"It is incredible to have the confirmation on the age of the human prints, and exciting but also sad to know that this is only a small portion of the 80,000 acres where the prints have been revealed bare and are also being rapidly lost to ongoing soil erosion," Bustos said.

The team also pioneered non-invasive geophysical techniques to help locate the site. Tommy Urban, from Cornell University, led this part of the work.

"Detection and imaging with nondestructive technology has greatly expanded our capacity to study these remarkable footprints in their broader context," he said.

Traditional archaeology relies on the discovery of bones and tools but can often be difficult to interpret. Human footprints provide unequivocal evidence of presence and also of behavior.

Read more at Science Daily