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^ I'll read that paper on S. American Atlantic coast migration routes this weekend.
But if humans were present in Beringia approx. 34 kya, then their presence in N. America 23000 years ago would make sense.
The genetic differences between these out-of-Asian populations should give good indications just how diverse Asians were during the Pleistocene.
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New research suggests the older dating of some footprints in the Americas may need to be verified.
quote: The wide expanse of an ancient lakebed in New Mexico holds the preserved footprints of life that roamed millennia ago. Giant sloths and mammoths left their mark, and alongside them, signs of our human ancestors. Research published in September 2021 claimed that these footprints are "definitive evidence of human occupation of North America" during the last ice age, dating back to between 23 and 21 thousand years ago. Now, a new study disputes the evidence of such an early age.
Scientists from DRI, Kansas State University, the University of Nevada, Reno, and Oregon State University caution in Quaternary Research that the dating evidence is insufficient for claims that would so radically alter our understanding of when, and how, humans first arrived in North America. Using the same dating method and materials, the new study shows that the footprints could have been left thousands of years later than originally claimed.
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^^ Dating can be tricky. Here is the abstract to the scientific study mentioned in the Science Daily article above:
quote: Abstract The ancient human footprints in valley-bottom sediments in Tularosa Valley, New Mexico, are fascinating and potentially important because they suggest interactions between Pleistocene megafauna as well as great antiquity. The dating of those footprints is crucial in interpretations of when humans first came to North America from Asia, but the ages have larger uncertainties than has been reported. Some of that uncertainty is related to the possibility of a radiocarbon reservoir in the water in which the dated propagules of Ruppia cirrhosa grew. As a test of that possibility, Ruppia specimens collected in 1947 from nearby Malpais Spring returned a radiocarbon age of ca. 7400 cal yr BP. We think it would be appropriate to devise and implement independent means for dating the footprints, thus lowering the uncertainty in the proposed age of the footprints and leading to a better understanding of when humans first arrived in the Americas.
A critical assessment of claims that human footprints in the Lake Otero basin, New Mexico date to the Last Glacial Maximum Quaternary Research, 2022 https://tinyurl.com/ycxfcc3s
Interesting and fascinating thought that these people lived side by side with animals belonging to the great megafauna of North America.
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One interesting clue to were in Asia Native Americans originally came from is also to look at the percentage of Denisova ancestry in them. It seems the Denisova percentage are more in line with mainland Asians than with for example Papuans.
Proportion of the genome inferred to be Denisovan in ancestry in diverse non-Africans. The color scale is not linear to allow saturation of the high Denisova proportions in Oceania (bright red) and better visualization of the peak of Denisova proportion in South Asia.
The map copied from Svante Pääbos Nobel lecture, but originally from Sankararaman et al., 2016: `The Combined Landscape of Denisovan and Neanderthal Ancestry in Present-Day Humans´ Current Biology 26, 1–7, May 9, 2016
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quote:New research suggests humans lived in South America at the same time as now extinct giant sloths, bolstering evidence that people arrived in the Americas earlier than once thought.
Scientists analyzed triangular and teardrop-shaped pendants made of bony material from the sloths. They concluded that the carved and polished shapes and drilled holes were the work of deliberate craftsmanship.
Dating of the ornaments and sediment at the Brazil site where they were found point to an age of 25,000 to 27,000 years ago, the researchers reported. That’s several thousand years before some earlier theories had suggested the first people arrived in the Americas, after migrating out from Africa and then Eurasia.
This is supposed to be the link to the original paper, but it hasn't been working for me tonight.
It is weird that we've yet to find human bones in the Americas of comparable age to these artifacts. Would be nice to get aDNA out of them.
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Seems that the link is working now. It is interesting to note that this find (if correctly dated) is about 11000-13000 years older than any human remains or human DNA found in the Americas.
quote:Abstract The peopling of the Americas and human interaction with the Pleistocene megafauna in South America remain hotly debated. The Santa Elina rock shelter in Central Brazil shows evidence of successive human settlements from around the last glacial maximum (LGM) to the Early Holocene. Two Pleistocene archaeological layers include rich lithic industry associated with remains of the extinct giant ground sloth Glossotherium phoenesis. The remains include thousands of osteoderms (i.e. dermal bones), three of which were human-modified. In this study, we perform a traceological analysis of these artefacts by optical microscopy, non-destructive scanning electron microscopy, UV/visible photoluminescence and synchrotron-based microtomography. We also describe the spatial association between the giant sloth bone remains and stone tools and provide a Bayesian age model that confirms the timing of this association in two time horizons of the Pleistocene in Santa Elina. The conclusion from our traceological study is that the three giant sloth osteoderms were intentionally modified into artefacts before fossilization of the bones. This provides additional evidence for the contemporaneity of humans and megafauna, and for the human manufacturing of personal artefacts on bone remains of ground sloths, around the LGM in Central Brazil.
Pansani, Thais R. et al 2023: Evidence of artefacts made of giant sloth bones in central Brazil around the last glacial maximum The Royal Society Link to the study
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quote:The Population Y signal related to Andamanese and Australasian populations could not be detected in the early Holocene Capelinha_10400BP individual or in the Amazonian Palmeiras Xingu_500BP individual. However, we report this signal in individuals from the southern sambaqui sites of Cabeçuda_3200BP and JabuticabeiraII_~2400BP. The latter is the only pre-colonial group exhibiting higher affinity to non-American ancestries even in direct comparison to another ancient Brazilian group (Supplementary Data 7). If confirmed, the sporadic identification of the Population Y signal in ancient individuals with different ancestries, locations and time periods across Brazil—where this signal was first described—suggests a higher probability that it derives from genetic structure in the founding Native American population than from multiple independent migrations into the Americas.
a, The archaeological sites analysed in this study, with the number of analysed individuals reported in brackets. Sites with newly reported genome-wide data are shown in black font, and those with previously published genome-wide data are shown in grey (this color scheme is maintained in all main text figures). The symbols used for each site refer to the associated archaeological cultures (see the legend in Extended Data Fig. 8). The shaded areas represent the broad geographic regions analysed in this work: (1) lower Amazon, (2) northeastern Brazil, (3) Lagoa Santa, (4a) southeastern Atlantic coast and (4b) southern Atlantic coast. The Kaingang burial is geographically closer to the southeastern Atlantic coast but was included in the southern Atlantic group due to its specific genetic affinity. The locations of present-day indigenous groups are represented with yellow dots. b, The calibrated ages (coloured bars) of single directly dated individuals with new genomic data and, in black font, the mean calibrated ages for the respective groups/individuals. For the previously published ancient genome-wide data62,63, the mean calibrated ages for the respective groups/individuals are reported in grey, whereas the white bars represent the temporal range of all directly dated individuals included in each group. Figure related to Supplementary Data 1.
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Interesting video that summarizes some of the debates about Population Y. One can also see that there can be a discrepancy between skull morphology and genetic ancestry shown for example in some examples from Lagoa Santa (in Brazil) whose skull morphology got some researchers to believe they had strong Australasian ancestry which their DNA refuted, and the Kennewick man whose features led people to believe that he had European ancestry which were contradicted by his DNA. One 9000 years old skull from Brazil has a skull morphology that clusters with both Native American and modern Vietnamese and Malaysian morphologies.
It is also interesting that the oldest Y -signals in America is about 1-3% and it has not changed, it is still about 1-3% in the groups which have the ancestry. Probably the people who brought it to the Americas had just a small percentage of it too.
My guess is that the mixing of population Y into a larger population of non Y people took place long time ago in Asia. ---- A little sidenote: In the film they talk about the Onge from the Andaman islands, but they mostly show pictures of the Jarawa, another Andamanese group. The Andamanese indigenous groups that live today are the Sentinelese, the Jarawa, the Onge and the Great Andamanese. The Onge and the Great Andamanese are very few. The Jarawa and Sentinelese have some more members but are still very few, just a couple of hundreds. One group, the Jangil, or Ruthland Jarawa, are completely extinct. -- In the film the thought that the Y signal comes from some ancient group of archaic humans in Asia is also forwarded. But as long as population Y is unsampled we can not really know.
Overall it is an interesting video that gives a background to the discussions about population Y. It also shows how much is still to learn about the ancient migrations who led to the peopling of the Americas.
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^ In regards to cranial morphology, I've explained here how the Zhoukoudian UC skulls of China show that the further you go back in prehistory especially past the Holocene cranial diversity is so great that modern racial concepts fail to describe them let alone identify genetic ancestry. Although I still believe the nonmetric odontic traits-- sundadonty vs. sinodonty-- does the best job in differentiating the ancestries involved in Paleo-American settlements.
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Yes, the skull morphologies of early Native Americans are rather varied, leading researchers to sometimes place them in different racial groups as in the case with Kennewick man and Luzia. In Quintana Roo in Mexico they found four different skulls whose traits reminded of different peoples, one was similar to other Native Americans and also Asians, one reminded about Arctic peoples, one looked more like European skulls and one had more indeterminable features. The four skulls covered a time span from c 13000 years ago to 9000 years ago.
Hubbe, Mark et al 2020: ´Morphological variation of the early human remains from Quintana Roo, Yucata ´n Peninsula, Mexico: Contributions to the discussions about the settlement of the Americas´ Plos One
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The morphological variation among early Native American skulls also left its traces in the different ways they have been reconstructed. Here is four examples all made by Cicero Moraes. Eve is from Mexico and is more than 13000 years old and is considered the oldest human fossil in the Americas. Apiuna and Diarum are both from Brazil and so is Zusu. Seems Cicero Moraes made them all rather different.
Interpretations of four early Native Americans, by Cicero Moraes
How the skull of Zuzu cluster with different populations. His skull morphology showed similarities with other Native Americans but also with modern Vietnamese and Malaysians.
quote:When positioning Zuzu's data on the study graph (Fig. 3), it is clear that it is close to the average nucleus of modern Vietnamese populations and American archaeological skulls, the latter include individuals from Lagoa Santa, sambaquis and other representatives of the Brazilian natural population comprising the colonial period, going back to more than 10,000 years BP. In addition, there is also a proximity to the population of modern Malays, that is, the structure researched has great affinity with the Asian group.
Australasian genetic influence spread wider in South America than previously thought The researchers found the Y marker in native people living on the Brazilian plateau in the center of the country and also in those living in the western part of the county—and they also found the signal in the Chotuna people of Peru. The findings suggest migrations of people with the Y signal were far more widespread in South America than were thought. Their findings also suggest that two waves of such migrations occurred. This has led to scrutiny of previous theories regarding how such individuals arrived in South America and why the signal has not been found in early North American people. Some have suggested it is because those in North America were wiped out by European colonists. Others have suggested that it is more likely that closer study of North American native people will eventually find some with the Y signal. And finally, the hardest theory to swallow is the possibility that early people from Australasia somehow made their way directly to the shores of South America.Posts: 26307 | From: Atlanta, Georgia, USA | Registered: Feb 2005
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Article about the different theories about the first peoples in Americas. The article mentions population Y but also the Solutréen hypothesis and the Bering strait model.
Among the interviewed experts are Jennifer Raff, a geneticist and anthropologist at the University of Kansas.
quote:“We don’t have any evidence, archaeologically or genetically, of a trans-Pacific migration,” says Raff. “We do have evidence of a faint signal of shared ancestry between some South Americans, both ancient and modern, and individuals in Australasia, but it doesn’t match what you would expect from a trans-Pacific migration. The signal would be a lot stronger in individuals on the West Coast, and less as you move farther East, but it doesn’t fit with that model. It’s scattershot throughout the population.”
Because of the nature of the signal, Raff and other geneticists believe that Population Y is very, very old, and originated in Asia (the same genetic signal was present in a 40,000-year-old man found in a Chinese cave). Tens of thousands of years ago, some descendants of Population Y went north and others went south. Some of those northern descendants ultimately crossed the land bridge and made it to South America, while some of the southern descendants populated Australasia.
Jennifer Raff is very skeptical towards the Solutréan hypothesis
quote:The Solutrean hypothesis has many critics, Meltzer and Raff among them. Meltzer wonders how an ancient people with no archeological evidence of boat-making could have navigated an ocean. “Look, the Titanic didn't make it,” he says. “How are a bunch of Solutreans in a boat going to cross the Ice Age North Atlantic?”
For Raff, the proof (or lack of it) is in the genetic record. In 2014, scientists sequenced the genome of the Anzick child, the remains of a Clovis-era boy in Montana who lived 12,700 years ago, making him the oldest burial in the Americas.
“The Anzick genome showed absolutely no genetic evidence of European ancestry, nor do any genomes of pre-contact Native Americans,” says Raff. “Anzick very roundly refuted the Solutrean hypothesis.”
Raff think that the most likely scenario is that the first people came to America in boats along the pacific coast
quote:For Raff and others, a more likely scenario is that the pre-Clovis humans reached America in boats. The western coastline of North America was ice-free thousands of years earlier than the interior. The pre-Clovis humans could have crossed the Bering Land Bridge on foot, then used simple boats to skirt around the glaciers and make their way down the West Coast of North and South America.
Genomic evidence also supports the coastal boat theory.
“All of the ancient genomes that have been sequenced carry the signature of rapid movement—the rapid divergence of different lineages in the Americas—suggesting that people were moving very quickly,” says Raff. “It’s harder to move that quickly on foot than by boat.”
It could be, says Meltzer, that there were many “pulses” of migrations into the Americas via the land bridge over several millennia, but that the pre-Clovis arrivals were highly mobile and relatively few in number.
“We know that people can be present long before they pop up on archeological radar,” says Meltzer. “It may be that what Clovis represented [13,000 years ago] was the population in the Americas finally getting to the point where there were enough of them out there producing enough stuff that they became archeologically visible—really visible.”
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In 2021 well preserved human footprints were found in White Sands in New Mexico. They were dated to between 21 000 and 23 000 years old.
Later these results were questioned. Among other things that were discussed were that there might have been a reservoir effect for carbon 14 in the seeds from aquatic plants that were used to date the foot prints.
Recently a new study was conducted where the datings were complemented with the radiocarbon dating of terrestrial pollen, and optically stimulated luminescence dating. The new results seem to confirm the original datings.
quote:Evidence of humans in North America during the Last Glacial Maximum
Despite a plethora of archaeological research over the past century, the timing of human migration into the Americas is still far from resolved. In a study of exposed outcrops of Lake Otero in White Sands National Park in New Mexico, Bennett et al. reveal numerous human footprints dating to about 23,000 to 21,000 years ago. These finds indicate the presence of humans in North America for approximately two millennia during the Last Glacial Maximum south of the migratory barrier created by the ice sheets to the north. This timing coincided with a Northern Hemispheric abrupt warming event, Dansgaard-Oeschger event 2, which drew down lake levels and allowed humans and megafauna to walk on newly exposed surfaces, creating tracks that became preserved in the geologic record. —AMS
quote:Human footprints at White Sands National Park, New Mexico, USA, reportedly date to between ~23,000 and 21,000 years ago according to radiocarbon dating of seeds from the aquatic plant Ruppia cirrhosa. These ages remain controversial because of potential old carbon reservoir effects that could compromise their accuracy. We present new calibrated 14C ages of terrestrial pollen collected from the same stratigraphic horizons as those of the Ruppia seeds, along with optically stimulated luminescence ages of sediments from within the human footprint–bearing sequence, to evaluate the veracity of the seed ages. The results show that the chronologic framework originally established for the White Sands footprints is robust and reaffirm that humans were present in North America during the Last Glacial Maximum.
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The Solutrean Hypothesis was refuted when it became apparent that the Y haplogroup R carried by Amerindians was from an entirely different line from that found in Western Europeans.
Not to mention that autosomal data shows no such connection.
Here are all the probable routes of entry for the peopling of the Americas.
Many scientists agree that it is most plausible to go around the Glacial barrier by using a coastal route.
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Yes, the only proven connection between Europe and America in precolumbian time is the Norse in L'Anse aux Meadows around 1000 AD. It also seems that the Norse on Greenland continued to travel to the Americas in order to collect timber during a couple of hundred years. It seems these contacts did not leave any discernible traces of "European" DNA among the Native American population. It is possible that it can have left some traces on Iceland though regarding mtDNA haplogroup C1e. But it is also possible that this haplogroup came from Europe or Asia.
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