Friday, November 29, 2019

Idaho researchers look for links between Clovis people & large mammals on the Snake River Plain

By IDAHO STATE UNIVERSITY  Nov 28, 2019  

About 13,000 years ago on the banks of the Pleistocene American Falls Lake on the Snake River Plain, large “megafauna” mammals now extinct — such as mammoths, mastodons, camels, short-faced bears, dire wolves & saber-toothed tigers — lived alongside the Clovis people.

However, Clovis artifacts have never been recovered side-by-side with fossil remains of these extinct megafauna mammals, even though they’ve been found near each other.

Charles Speer, an Idaho State University anthropology assistant professor, along with colleagues at the Idaho Museum of Natural History, other universities & soon with ISU students, is engaged in research to document the link between the artifacts of the Clovis people & these extinct animals that populated the area during the same time period.
Charles Speer holds part of a mammoth fossil recovered at the 2018 ISU Archaeology Field School site in the Magic Valley near Kimberly. Next summer, Speer & the school will be working closer to home near American Falls Reservoir.

In a recently published paper on Clovis technology from American Falls on the Eastern Snake River Plain in the journal “North American Archaeologist,” Speer & colleagues detailed the potential for making new scientific findings that can shed light on this period of history in eastern Idaho. This potential includes discovering new information on the area’s climate, animals & people; all of which provides the rationale for thoroughly excavating a site in the area.

“We don’t have a connection in the Snake River Plain between Clovis stone tools, some of the earliest in North America, & the megafauna we have at the time,” Speer said. “We haven’t found any kill, butchering, or scavenging sites where we have the stone tools & animals in the same place. At the American Falls (reservoir) site, it is highly likely that we will find this connection. This next summer during the ISU archaeology field school in June, that is exactly what we are going to be looking for.”

The ISU researchers will be excavating a site down 8 to 10 feet below the surface. “The primary reason we are excavating is that the whole area is in danger of eroding away,” Speer said, noting the group has been tasked by the Bureau of Reclamation to recover as much as they can.

Speer explained that the climate on this portion of the Snake River Plain was likely colder & wetter 13,000 years ago. The climate was affected by the large glaciers to the north extending down from Canada only a few hundred kilometers away. Though the climate was cooler, this area was a magnet for the animals mentioned above, as well as familiar species still making the region home like mule deer, antelope, bison & elk.

“People camped out there, made their tools & hunted the animals. We really just want to make that connection showing they were exploiting these extinct animals because that is a big missing piece,” Speer said.

Studying the climate at the time & potential kill sites can help answer a host of questions about this area’s history.  “We are interested in the animals that died off right when this Clovis culture was at its peak,” Speer said. “We ask questions like ‘did these people kill all these animals, was it climate change or was it both?’ In North America alone, 90 genera of animals over 100 pounds died off during the Clovis period at the close of the Pleistocene 11,700 years ago,” Speer said. This included horses, that flourished when re-introduced 500 years ago by Europeans.

The researchers also are interested in how human beings reacted to climate change during this period, which was right at the end of the Pleistocene period, after which the climate warmed & dried considerably.

In addition, the researchers will be looking for evidence of a culture older than the Clovis living in eastern Idaho.  “Clovis for the longest time was thought to be the oldest culture in North America but know we know it is not,” Speer said. “Researchers in western Idaho have been excavating the Cooper’s Ferry site that is associated with a projectile point style called ‘Western Stemmed’ that is both contemporaneous & potentially older than Clovis. Additionally, they have recovered artifacts several thous& years older which we hope to also discover & fill in the missing pieces with here.”

“We are hoping to see an overlap & connection between the two,” Speer continued, “because we are right on this boundary where to the east you have Clovis in abundance & to the west we have Western Stemmed in abundance, but we don’t have any sites where the two are mixed up. We are also hoping to see the site stretch back in time to 17,000 or 18,000 years ago.”

The researchers will turn over any artifacts found at the site to the Idaho Museum of Natural History, which already has more than 10,000 specimens of megafauna that lived in the area & a collection of Clovis artifacts from the American Falls area.

Thursday, November 21, 2019

America's Early Peoples (mostly on the Pacific Coast)

As a historian of North America, specifically the area now called the United States, I am intrigued with, almost obsessed with, when humans 1st appeared in the Atlantic coast area later settled by European colonists. How did these early peoples try to gain some control over weather patterns & geography? Did they create physical spaces to meet their basic needs for shelter, food, family, health, & safety. How did they organize their society & culture? Did they migrate by foot or on water to these sites? Did they generate myths & religions? Looking to science for answers to these questions is frustrating, at best. Humans have a long history of constant migration, confrontation, & adaptation for hundreds of thousands of years. And, of course, different populations around the planet adapted to different conditions in different ways.  BWS

For decades, archaeologists associated finely fluted spear points—such as the two points at right—with the first people to live in the Americas. Image: Denver Museum of Nature & Science

A November 14, 2019, "Why it’s so challenging to determine ‘how and when’ humans first set foot in the Americas" by Megan Gannon published by the Genetic Literacy Project tells us that some arrived in North America by boat. The following information is gleaned from her article...


In 2014, a group of Canadian researchers uncovered human footprints pressed into a prehistoric layer of soil. The footprints, 29 in total, are the oldest found in North America. They suggest that 13,000 years ago, at least 3 people may have splashed out of a boat onto the damp shore.

North & South America seem to be the last major landmasses in the world to be populated by Homo sapiens. But the explanation of how & when this peopling happened has been heavily revised in the last 2 decades. New data, especially from the Pacific coast areas, including genetic findings, continue to complicate the story of how these continents came to be peopled.

The search intrigued archaeologist Edgar B. Howard when he learned in 1932, of mammalian fossils coming from a site called Blackwater Draw in New Mexico. A construction crew had exposed an extensive deposit of bison & mammoth bones, & there Howard found spear points & other human artifacts scattered among the remains of extinct mammoths, camels, & bison. At the time, researchers were only beginning to appreciate that humans were in the Americas during the last ice age, which ended around 10,000 years ago. In the years to follow, archaeologists would unearth sleek, fluted spear points, just like the ones found at Clovis, across North America. These artifacts came to be known as Clovis points & linked to people whom archaeologists considered the “first Americans.”

In the 1930s it was a  belief among many anthropologists that ancestral Native Americans descended from people living in Asia who crossed into the Americas over a now-submerged open tundra bridging Russia & Alaska, the Bering Land Bridge, also known as Beringia. From there, these people were speculated to have traversed a narrow passage between glaciers covering Alaska & Canada that only opened up about 13,500 years ago. The prevalence of Clovis-style spear points, which generally date between 13,250 & 12,800 years old, suggested that the first people in the Americas spread quickly after their arrival. Scientists broadly referred to this narrative—encompassing not just the cultural artifacts but also the time frame & land bridge—as the Clovis-first model.

Eventually cracks appeared in the Clovis-first model. In 1976 Chile, researchers excavating at Monte Verde uncovered undeniable traces of a human presence, preserved under peat. Researchers have confidently dated the most substantial cultural layer to about 14,500 years before the present day—at least 1,000 years older than the Clovis-first model would predict. We learned that people slept there under a long, tent-like structure made of wood & animal hides & sat around communal hearths eating potatoes & seaweed brought from trips to the coast.  In 1997, Monte Verde was inspected by a delegation of archaeologists, many of whom had questioned its purported age. They left in agreement that the site was old, indeed. Since then, in North America, several sites have gained wide acceptance as authentically pre-Clovis, but most of these older sites have no distinct artifacts to connect them.

The present method for dating artifacts is carbon dating. Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Nobel Prize winning chemist Willard Libby. Presently, we can only date organic material using carbon dating, so artifacts like stone arrow heads can only be dated by association with the organic material they were found with.  The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within specific archaeological sites, it allows comparison of dates of events across great distances. Carbon dating is a useful tool but not a precise tool.  BWS

Att Oregon’s Paisley Caves, archaeologists have dated fossilized human feces to 14,300 years ago. Beneath the Clovis layers along the shores of Buttermilk Creek in Texas, researchers have found thousands of stone tool fragments dating back 15,500 years. And on the Atlantic coast side of the nation, reportedly, The Meadowcroft Rockshelter in Pennsylvania, has a human history that may stretch back at least 16,000 years. 

Most archaeologists, even the most conservative, would now agree that there were widely scattered, small but culturally diverse groups of people living in the Americas at least one or two millennia before the emergence of Clovis spear points.

Genetics also shed light on how & when entire lineages of people moved across continents. Genetic markers from the DNA of a child buried in what is now Alaska around 11,500 years ago, for instance, recently revealed that she shared equal DNA with all Indigenous populations in the Americas. The authors concluded she was likely descended from a population that remained in Beringia, instead of spreading through the lower continents. The Beringian population seems to have diverged from Siberian populations around 36,000 years ago. About 25,000 years ago, the Beringians became isolated, & a new genetic population emerged, one that scientists have confirmed relates to contemporary Native American people, splitting into 2 main lineages around 17,000 years ago. However, only a handful of ice age human remains have been studied at all—and archaeological data are needed to both confirm that story & help fill in the ancient pathways that humans first took across the continents.

The genetic data suggest one population may have spent thousands of years in Beringia, before spreading south into the Americas sometime during the Last Glacial Maximum between 27,000 & 19,000 years ago. Because of the ice, some claim that migrating people of the period did not walk but used boats. According to this coastal migration theory, some 16,000 years ago the ice had retreated from the coastlines of the Pacific Northwest, such that oceangoing people could take advantage of coastal resources like kelp forests to navigate all the way down the shores of California, eventually reaching sites like Monte Verde in Chile But no wooden boats from that era have been found along these shorelines. Some speculate that evidence of human habitation from at least 13,000 years ago on the Channel Islands in California indicates that people probably had the skills to build boats & reach these land masses.

More Evidence that 1st Americans came from the Pacific Coast

New Evidence Bolsters Theory That 1st Americans Arrived by the Pacific Coast

Gizmodo.com  by George Dvorsky  8/29/19
Archaeological evidence excavated in western Idaho suggests humans were in the region well over 15,000 years ago—prior to the opening of the massive ice sheets that blocked entrance into North America via the Bering land bridge. It’s further evidence that the continent’s first people arrived by traveling along the Pacific coast.

Prior to the Late Upper Paleolithic, humans had established a presence on every habitable continent on the planet—except North and South America. A gigantic and impenetrable obstruction known as the Cordilleran Ice Sheet blocked entry from Siberia into Alaska, preventing human migration into the New World.

But as the last great Ice Age ended, so too did this colossal barrier. Around 14,800 years ago, the Cordilleran Ice Sheet separated from its neighboring Laurentide Ice Sheet, creating an ice-free corridor that extended from Beringia through to what is now the Dakotas. This dramatic change in the environment has led archaeologists to surmise that the earliest migrants to North America arrived by traversing this corridor, in what’s referred to, appropriately enough, as the Ice-Free Corridor Hypothesis.

Trouble is, emerging archaeological and genetic evidence is increasingly pointing to an arrival date in North America prior to 14,800 years ago, leading to the Coastal Migration Hypothesis. Instead of traveling through the interior, this theory proposes a route in which the first settlers of North America traveled south along the Pacific coast, eventually surpassing the southernmost extent of the ice sheets.

New research published today in Science offers some of the earliest archaeological evidence of humans in North America, further bolstering the Coastal Migration Hypothesis. Working at the Cooper’s Ferry site in western Idaho, a team led by Loren Davis, a professor of anthropology at Oregon State University, uncovered stone tools, animal bones, traces of fire pits, and other signs of human occupation dated to between 16,560 and 15,280 years ago—several centuries prior to the appearance of the ice-free corridor.

“This is so cool,” Christiana Scheib, an archaeologist and paleogeneticist from the University of Cambridge, told Gizmodo. “This is a great example of the kind of archaeology we need happening in order to better understand the First Peoples in the Americas,” said Scheib, who wasn’t involved with the new study.

Archaeologist Alia Lesnek from the Department of Geology at the University at Buffalo, also not affiliated with the new study, said the new paper “presents an exciting new dataset that provides convincing evidence of human presence in modern-day Idaho as early as 15,300 years ago,” and that these results “add to a growing body of research suggesting that the First Americans arrived in North America by traveling along the Pacific coast.”

Last year, Lesnek and her colleagues uncovered potential geological evidence of an Alaskan coastal migration route that could have allowed humans to cross over from Eurasia into North America during the Ice Age.

But not everyone is convinced by the new evidence. One archaeologist we spoke to said more work will be required to validate the results presented in the new paper. The study describes findings from one of two excavation sites at Cooper’s Ferry, which has been investigated by archaeologists since the late 1990s.

“The Cooper’s Ferry site is located along the Salmon River, which is a tributary of the larger Columbia River basin,” said Davis in a press release. “Early peoples moving south along the Pacific coast would have encountered the Columbia River as the first place below the glaciers where they could easily walk and paddle in to North America. Essentially, the Columbia River corridor was the first off-ramp of a Pacific coast migration route.” To which he added: “The timing and position of the Cooper’s Ferry site is consistent with and most easily explained as the result of an early Pacific coastal migration.”



Buried within the deepest layers of the site, Loren’s team found hundreds of artifacts, including stone tools, fire-cracked rocks used in hearths, bone fragments from possibly prey, and other evidence of human occupation, such as areas used for processing food. Tooth fragments from an extinct horse were also uncovered, though its connection to the settlement is not entirely clear.

Radiocarbon dating of animal bone fragments and burnt charcoal suggests the site was repeatedly occupied between 16,560 and 15,280 years ago. “Prior to getting these radiocarbon ages, the oldest things we’d found dated mostly in the 13,000-year range, and the earliest evidence of people in the Americas had been dated to just before 14,000 years old in a handful of other sites,” explained Davis. “When I first saw that the lower archaeological layer contained radiocarbon ages older than 14,000 years, I was stunned but skeptical and needed to see those numbers repeated over and over just to be sure they’re right. So we ran more radiocarbon dates, and the lower layer consistently dated between 14,000-16,000 years old.”

The new paper subsequently challenges the longstanding “Clovis First” theory of North American colonization, which proposes that the first migrants to the continent arrived via the interior ice-free route, eventually reaching the Dakotas. What’s more, the authors presented evidence showing that the tools used by the Cooper’s Ferry migrants were of a distinctly non-Clovis-like nature. Specifically, these people employed unfluted and stemmed projectile points, and not the fluted, broad-based points indicative of Clovis culture. Loren and his colleagues also argued that the tools used by the Cooper’s Ferry people bear a striking resemblance to those found in contemporaneous cultures living in northeastern Asia, including Japan. This would seem to suggest that these early migrants retained knowledge of this technology as they settled into North America.

“My perspective is that Cooper’s Ferry is intriguing, but not paradigm-shifting.” Ben Potter, an archaeologist from the University of Alaska Fairbanks, had some issues with the new paper. “My perspective is that Cooper’s Ferry is intriguing, but not paradigm-shifting,” Potter told Gizmodo. “Much more work needs to be done to establish the nature and age of the occupations.”

Potter expressed concerns about the layer itself, which he described as a hodge-podge of “multiple potentially overlapping components over four thousand years.” He also didn’t love the fact that the majority of dates established within the investigated layer were less than 13,800 years old (10 out of the 18 ages reported). There is “no good reason to hypothesize occupation” at more than 16,000 years ago “because of a few widely scattered charcoal fragments not directly linked to cultural feature, and one from a feature with much later ages,” he said. The date presented in the study most closely linked with stemmed points at other sites, around 11,600 years old, or the oldest hearth with a few flakes between 15,000-14,000 years old, he said, do not “preclude passage through the Ice Free Corridor and/or the Pacific coast,” and by “no means do these data refute the [ice-free corridor] hypothesis. Both interior and coastal routes remain viable,” he said.

On a similar note, Lesnek thought it important to point out that the oldest age established for the site, at over 16,500 years old, was not established directly from material that was actually dated. “Rather, that age comes from a statistical modeling program that uses dates from the entire sediment layer to estimate when the event—in this case occupation by humans—began,” Lesnek told Gizmodo. “However, the statistical modeling program the authors employ is robust and widely used in archeology and earth sciences. In addition, even if the authors used the oldest radiocarbon date to determine the age of the site, that would put humans in North America by 15,300 years ago, which precludes that the initial migration to the Americas took place through the ice-free corridor.”

Potter described the comparisons of the stemmed points with Japanese tools as being “superficial and unconvincing,” without “any technological analysis to support the hypothesized connections.” Similarly, Scheib said this connection was “interesting,” but it “doesn’t mean that these people came directly from there,” she told Gizmodo.

Scheib, who studies the DNA of America’s first people, said an early genetic split occurred among North America’s first settlers, and it may have happened around the time of the Cooper’s Ferry settlement. “One group is associated with Clovis tools and related to modern Central and South Americans and the other is related to modern North Americans,” Scheib told Gizmodo. “It would be very interesting to know whether the early people at Cooper’s Ferry are genetically more like one or the other. Or if this is the time when these two groups are actually becoming distinct entities.” Genetic evidence from Cooper’s Ferry—which has yet to be uncovered—could tell us more about how and where these two populations diverged, she said. Finding DNA could be tough but not impossible.

“The cultural material at Cooper’s Ferry was only accessible due to the construction of a road in the 1930s, which removed about 15 feet of sediment,” Lesnek told Gizmodo. “It may very well be that other ancient archeological sites are buried across North America, but we haven’t found them yet.”

As a historian of North America as the Europeans began to colonize the area now the United States, I am intrigued with, almost obsessed with, when humans 1st appeared in the Atlantic coast area later settled by European colonists. How did these early peoples try to gain some control over the weather patterns & geography? Did they create physical spaces to meet their basic needs for shelter, food, family, health, & safety. How did they organize their society & culture? Did they migrate on foot or water to these sites? Did they generate myths & religions? Looking to science for answers to these questions is frustrating. Humans have a long history of constant migration, confrontation, & adaptation for hundreds of thousands of years. And, of course, different populations around the planet adapted to different conditions in different ways.  BWS

Ancient Peoples Migrate between Siberia & Western North America

Ancient DNA Reveals Complex Story of Human Migration Between Siberia & North America. Two studies greatly increase the amount of information about the peoples who first populated North America—from the Arctic to the Southwest U.S.  Arctic hunter-gatherers, Paleo-Eskimos, made a significant genetic contribution to populations living in North America today. 

By Brian Handwerk Smithsonian.com June 5, 2019

There is plenty of evidence to suggest that humans migrated to the North American continent via Beringia, a land mass that once bridged the sea between what is now Siberia and Alaska. But exactly who crossed, or recrossed, and who survived as ancestors of today’s Native Americans has been a matter of long debate.

Two new DNA studies sourced from rare fossils on both sides of the Bering Strait help write new chapters in the stories of these prehistoric peoples.

The first study delves into the genetics of North American peoples, the Paleo-Eskimos (some of the earliest people to populate the Arctic) and their descendants. “[The research] focuses on the populations living in the past and today in northern North America, and it shows interesting links between Na-Dene speakers with both the first peoples to migrate into the Americas and Paleo-Eskimo peoples,” Anne Stone, an anthropological geneticist at Arizona State University who assessed both studies for Nature, says via email.

Beringia had formed by about 34,000 years ago, and the first mammoth-hunting humans crossed it more than 15,000 years ago and perhaps far earlier. A later, major migration some 5,000 years ago by people known as Paleo-Eskimos spread out across many regions of the American Arctic and Greenland. But whether they are direct ancestors of today’s Eskimo-Aleut and Na-Dene speaking peoples, or if they were displaced by a later migration of the Neo-Eskimos, or Thule people, about 800 years ago, has remained something of a mystery.
Beringa  Map of what was once the Beringia connection between present-day Siberia and Alaska. (National Park Service)

An international team studied the remains of 48 ancient humans from the region, as well as 93 living Alaskan Iñupiat and West Siberian peoples. Their work not only added to the relatively small number of ancient genomes from the region, but it also attempted to fit all the data together into a single population model.

The findings reveal that both ancient and modern peoples in the American Arctic and Siberia inherited many of their genes from Paleo-Eskimos. Descendants of this ancient population include the Yup’ik, Inuit, Aleuts and Na-Dene language speakers from Alaska and Northern Canada all the way to the Southwest United States. The findings stand in contrast to other genetic studies that had suggested the Paleo-Eskimos were an isolated people who vanished after some 4,000 years.

"For the last seven years, there has been a debate about whether Paleo-Eskimos contributed genetically to people living in North America today; our study resolves this debate and furthermore supports the theory that Paleo-Eskimos spread Na-Dene languages," co-author David Reich of Harvard Medical School and the Howard Hughes Medical Institute says in a press release.

The second study focused on Asian lineages, Stone notes. “The study is exciting because it gives us insight into the population dynamics, over 30-plus thousand years, that have occurred in northeastern Siberia. And these insights, of course, also provide information about the people who migrated to the Americas.”

Researchers retrieved genetic samples for 34 individuals’ remains in Siberia, dating from 600 to 31,600 years old. The latter are the oldest human remains known in the region, and they revealed a previously unknown group of Siberians. The DNA of one Siberian individual, about 10,000 years old, shows more genetic resemblance to Native Americans than any other remains found outside of the Americas.

Fifteen years ago scientists unearthed a 31,000-year-old site along Russia’s Yana River, well north of the Arctic Circle, with ancient animal bones, ivory and stone tools. But two tiny, children’s milk teeth are the only human remains recovered from the Ice Age site—and they yielded the only human genome yet known from people who lived in northeastern Siberia during the period before the Last Glacial Maximum. They represent a previously unrecognized population that the study’s international team of authors have dubbed “Ancient North Siberians.”

The authors suggest that during the Last Glacial Maximum (26,500 to 19,000 years ago) some of these 500 or so Siberians sought more habitable climes in southern Beringia. Stone says the migration illustrates the ways that shifting climate impacted ancient population dynamics. “I do think that the refugia during the Last Glacial Maximum were important,” she says. “As populations moved to refugia, likely following the animals they hunted and to take advantage of the plants they gathered as those distributions shifted south, this resulted in population interactions and changes. These populations then expanded out of the refugia as the climate warmed and these climate dynamics likely affected population around the world.”

In this case, the Ancient North Siberians arrived in Beringia and likely mixed with migrating peoples from East Asia. Their population eventually gave rise to both the First Peoples of North America and other lineages that dispersed through Siberia.

David Meltzer, an anthropologist at Southern Methodist University and coauthor of the new study, says when the Yana River site was discovered, the artifacts were said to look like the distinctive stone tools (specifically projectile “points”) of the Clovis culture—an early Native American population that lived in present-day New Mexico about 13,000 years ago. But the observation was greeted with skepticism because Yana was separated from America’s Clovis sites by 18,000 years, many hundreds of miles, and even the glaciers of the last Ice Age.

It seemed more likely that different populations simply made similar stone points in different places and times. “The odd thing is, now as it turns out, they were related,” Meltzer says. “It’s kind of cool. It doesn’t change the fact that there’s no direct historical descent in terms of the artifacts, but it does tell us that there was this population floating around in far northern Russia 31,000 years ago whose descendants contributed a bit of DNA to Native Americans.”

The finding isn’t particularly surprising given that at least some Native American ancestors have long been thought to hail from the Siberian region. But details that seemed unknowable are now coming to light after thousands of years. For example, the Ancient North Siberian peoples also appear to be ancestral to the Mal’ta individual (dated to 24,000 years ago) from the Lake Baikal region of southern Russia, a population that showed a slice of European roots—and from whom Native Americans, in turn, derived some 40 percent of their ancestry.

“It’s making its way to Native Americans,” Meltzer says of the ancient Yana genome, “but it’s doing so through various other populations that come and go on the Siberian landscape over the course of the Ice Age. Every genome that we get right now is telling us a lot of things that we didn’t know because ancient genomes in America and in Siberia from the Ice Age are rare.”

A more modern genome from 10,000-year-old remains found near Siberia’s Kolyma River evidences a DNA mix of East Asian and Ancient North Siberian lineages similar to that seen in Native American populations—a much closer match than any others found outside of North America. This finding, and others from both studies, serve as reminders that the tale of human admixture and migration in the Arctic wasn’t a one-way street.

“There’s absolutely nothing about the Bering land bridge that says you can’t go both ways,” Meltzer says. “It was open, relatively flat, no glaciers—it wasn’t like you wander through and the door closes behind you and you’re trapped in America. So there’s no reason to doubt that the Bering land bridge was trafficking humans in both directions during the Pleistocene. The idea of going back to Asia is a big deal for us, but they had no clue. They didn’t think they were going between continents. They were just moving around a large land mass.”

As a historian of North America as the Europeans began to colonize the area now the United States, I am intrigued with, almost obsessed with, when humans 1st appeared in the Atlantic coast area later settled by European colonists. How did these early peoples try to gain some control over the weather patterns & geography? Did they create physical spaces to meet their basic needs for shelter, food, family, health, & safety. How did they organize their society & culture? Did they migrate on foot or water to these sites? Did they generate myths & religions? Looking to science for answers to these questions is frustrating. Humans have a long history of constant migration, confrontation, & adaptation for hundreds of thousands of years. And, of course, different populations around the planet adapted to different conditions in different ways.  BWS

The Extremely Fast Peopling of the early Americas

Two genetic studies show how the first Native Americans spread through their new continent with incredible speed.

The Atlantic  by ED YONG  November 8, 2018


Sebastian Munster Map of North & South America c 156

Tens of thousands of years ago, two gigantic ice sheets smothered the northernmost parts of what has since been named North America. They towered more than two kilometers high and contained 1.5 times as much water as Antarctica does today. They were daunting, impassable barriers to the early humans who had started moving east from Asia, walking across a land bridge that once connected the regions now known as Russia and Alaska. But once the ice started to melt, these peoples—the ancestors of the Americas’ Indigenous groups—spread southward into new lands.

What happened next?

Genetic studies, based on ancient remains, had already suggested that once the first American Indians got south of the ice, 14,600 to 17,500 years ago, they split into two main branches. One stayed north, giving rise to the Algonquian-speaking peoples of Canada. The other headed south, giving rise to the widespread Clovis culture, and to Central and South Americans. That’s a very rough outline, but a new study from J. Víctor Moreno-Mayar and his colleagues fleshes it out. They showed that whatever happened south of the ice, it happened fast.

They sequenced the genomes of 15 ancient humans, who came from sites ranging all the way from Alaska to Patagonia. One person from Spirit Cave in Nevada and five from Lagoa Santa in Brazil were especially instructive. They were all just over 10,000 years old, and though they lived 6,300 miles apart, they were strikingly similar in their DNA. Genetically, they were also closely matched to Anzick-1—a famous Clovis infant from Montana, who was about 2,000 years older.

All this suggests that, about 14,000 years ago, the southern lineage of early American Indians spread through the continent with blinding speed. To picture their movements, don’t think of a slowly growing tree, incrementally sending out new branches and twigs. Instead, imagine a starburst, with many rays zooming out simultaneously and rapidly.

In a matter of centuries, these people had gone down both sides of the Rockies, across the Great Basin, and into Mexico’s highlands. Within a couple more millennia, they had zipped down the Andes, through the Amazon, and as far south as the continent allowed. “Once they were south of the ice, they found a territory that was open, vast, and full of resources,” says Moreno-Mayar, who is based at the University of Copenhagen. “They were adept hunter-gatherers, so they expanded very quickly.”

This pattern confirms the suspicions of archaeologists, whose finds had long suggested that humans suddenly appeared throughout the Americas, from about 13,000 years ago onward. “You can now see that in the genetics,” Moreno-Mayar says.

Coincidentally, a second group of researchers, fronted by Cosimo Posth of the Max Planck Institute for the Science of Human History, independently found the same pattern. They studied the DNA of 49 ancient humans from Central and South America and found similar evidence for a rapid starburst expansion, and a southward migration that connects the Clovis culture of the north to early peoples in Belize, Brazil, and Chile.

These studies show that the histories of the Americas are more complicated than earlier genetic studies suggested, says Deborah Bolnick, an anthropologist from the University of Connecticut. But that’s more because those studies were overly simplistic to begin with rather than because the new results are surprising. “Many lines of evidence, including archaeological research, linguistic data, and Indigenous histories, have suggested that multiple groups of people—related, descended from shared ancestors, but still distinct—have lived, moved, and interacted in the Americas over the millennia,” she says. “Broadly, that is what these [new] studies show.”

They’re not just reinventing the wheel, though. For example, the tools of the Clovis people were so different from those found at Spirit Cave (which lies on the other side of the Rockies) that some researchers took them as evidence that the Americas were peopled by two genetically distinct founding groups. Moreno-Mayar and his colleagues have disproved that idea: They showed that the two groups were genetically similar, if culturally distinct.

Both teams also found evidence of later waves of migration that took place long after the Americas had been initially peopled—although the details differ between the two studies. Posth’s data point to a second wave of people who entered South America about 9,000 years ago, whose genes displaced those of the earlier Clovis-related people, and who had a direct connection to Indigenous groups today. By contrast, Moreno-Mayar’s data speak to a gentler process, in which relatively small groups slowly spread both north and south from Mexico from 8,000 years ago, adding their genes to the local populations without swamping them. Either way, they “challenge the idea that present-day native peoples all descend from a single, homogenous ancestral population,” says Maria Nieves-Colón, a geneticist based in Mexico’s langebio institute.

The two studies also differ on a particularly puzzling and controversial result. Back in 2015, the leaders of both Posth’s and Moreno-Mayar’s teams found that today’s Indigenous Amazonians share small hints of ancestry with people from Australia and Papua New Guinea—places on the other side of the Pacific. In their new study, Moreno-Mayar’s team found that same tantalizing smidgen of Australasian ancestry in the 10,400-year-old remains from Lagoa Santa in Brazil, but in none of the other remains they tested. “Every explanation that we can come up with for that is less plausible than the last,” says Moreno-Mayar.

If people with Australasian ancestry somehow entered the Americas before the early American Indians, how did they get into Brazil without leaving any trace in North America, either genetically or archaeologically? If they entered after the first American Indians did, how did they get from Alaska to Brazil seemingly without interacting with anyone else? If they sailed across the entire Pacific, after hypothetically inventing seafaring technology millennia before the Polynesians, how did they cross the Andes and traverse the Amazon?

It doesn’t help that Posth’s team didn’t find any Australasian DNA among their ancient remains, including ones from the same region of Brazil. It could be that people from that area were very diverse—or that the Australasian signal is a mistake. “The only way to get a better answer is to do more studies on other ancient samples,” adds Moreno-Mayar.

As a historian of North America as the Europeans began to colonize the area now the United States, I am intrigued with, almost obsessed with, when humans 1st appeared in the Atlantic coast area later settled by European colonists. How did these early peoples try to gain some control over the weather patterns & geography? Did they create physical spaces to meet their basic needs for shelter, food, family, health, & safety. How did they organize their society & culture? Did they migrate on foot or water to these sites? Did they generate myths & religions? Looking to science for answers to these questions is frustrating. Humans have a long history of constant migration, confrontation, & adaptation for hundreds of thousands of years. And, of course, different populations around the planet adapted to different conditions in different ways.  BWS