Denisovans in America... I found an article about this possibility

My search for scholarly articles about an early peopling of America struck gold today. I came across a post on a blog that was structured like a research paper, which is a nice detail. It was written by Riley Rogerson, and its title is Multi-Level Hominin Migration and Denisovan Presence in the Americas posted on 2025/07/09. It even includes bibliographic references. Well done!

You can read the post at Rogerson's blog, the white letters against a black background make it hard on the eyes (by the way, I also dislike the beige background I chose for my blog, but now it is too late to change it!). Below I summarize the main points and include links to any post I may have written about a specific item.

Abstract: "This theory proposes that Denisovans, an archaic hominin group closely related to Neanderthals, may have been the earliest hominin migrants to the Americas. A 130,000-year-old archaeological site in California suggests hominin activity long before anatomically modern humans are known to have left Africa. During this period, Denisovans inhabited Siberia and may have crossed the Beringia land bridge, establishing ephemeral populations in North America. These groups likely died out without descendants but left behind physical traces. Later, modern humans who interbred with Denisovans in Eurasia crossed into the Americas in intermittent migration waves taking place possibly as early as 37,000 years ago. Genetic findings in a 1,500-year-old skeleton from Uruguay confirm persistent Denisovan ancestry in Indigenous populations, supporting the idea of earlier, layered migrations. This model complicates the standard peopling narrative and opens new avenues for understanding pre-Clovis human history in the Americas."

The article looks into Monte Verde site in Chile (clearly Pre-Clovis, despite current arguments that it is much more recent), the 130 ky old mastodon bones from the Cerutti site in California, the Hartley site (37 ky) in New Mexico, and the 23 ky old footsteps from White Sands.

It correctly argues in favor of an Older Land Bridge between Asia and America: "During periods of low sea level, including Marine Isotope Stage 5e (~130,000 years ago), the Bering land bridge connected northeastern Asia to Alaska, providing a viable (though harsh) migration route for Pleistocene megafauna and, potentially, archaic hominins such as the Denisovans."

I found the comment of admixture within America (Denisovans and modern humans) extremely interesting; it explains the "...elevated Denisovan signature. First, it might indicate a major admixture event occurring in ancestral populations prior to entry into the Americas, resulting in sustained higher levels of Denisovan ancestry in certain lineages. It could alternatively reflect more complex regional population dynamics, such as secondary admixture events occurring within the Americas, potentially involving remnant populations carrying substantial Denisovan ancestry from earlier migrations. This hypothesis implies that Denisovan genetic influence in the Americas may not have been uniformly diluted over time but instead persisted regionally or was periodically refreshed by contacts with isolated groups."

The author argues that "Recent archaeological findings further complicate the picture. Several controversial sites in eastern Beringia, including Old Crow Basin, Chandalar River, and the deeper strata of Bluefish Caves, have produced lithic tools and faunal remains that some researchers interpret as evidence of hominin activity dating from approximately 80,000 to 100,000 years ago. These dates precede the known arrival of anatomically modern humans in northeast Asia, raising the possibility that these occupations reflect short-lived incursions by Denisovan groups during glacial periods when the Bering Land Bridge was exposed. While the artifact status of some materials is debated, the timing and geography align with what is known about Denisovan range and climate-accessible corridors."

The paper suggests some potential avenues for further research, including genetics: "high-resolution mapping of archaic DNA segments in Indigenous populations, may help distinguish between Denisovan ancestry acquired in Asia and ancestry potentially inherited from archaic populations present in the Americas. Third, paleoenvironmental reconstructions of Beringia during MIS 5e and related periods can refine our understanding of when and how migrations might have occurred."

The article is well structured and presents the evidence in a straightforward manner. No controversy, just facts. Well done!

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2026 by Austin Whittall © 

Siberia to America 400 kya? Very Possible

In my last two posts, I mentioned two Siberina sites that are over 400,000 years old, one is Diring Yuirakh, the other is Karama, both had been originally dated at over 1.5 million years (My), an age that was later revised to a more recent 400 to 800 kya.

These people were not modern humans, our lineage originated 300,000 years ago. They were either Denisovans (who lived in East Asia), Neanderthals on their easternmost reaches, or the predecessor of both groups, Homo heidelbergensis, the tools discovered at both sites are primitive cobble sytle stone tools, older than the Acheulean used by Homo erectus and the Mousterian of the Neanderthals (We don't have tools used by Denisonvans), these Siberian tools resemble the Oldowan industry used in Africa over 2 My ago. These sites could also have belonged to H. erectus, who arrived in Eurasia around 2 My ago.

The sites, located in Siberia, in a cold and harsh region suggest that those who lived there were well adapted to the tough climate. They must have mastered fire, used warm clothes, built decent shelters, and had a good knowledge of their environment. They could have survived futher east and north, all the way to Bering Strait, and beyond.

Could they have advanced and reached America?

In my post on Diring Yuriakh and its age, I mentioned the work of John D. Janssen et al., 2024 (Redrawing early human dispersal patterns with cosmogenic nuclide, EGU24-4168, updated on 08 Mar 2024. https://doi.org/10.5194/egusphere-egu24-4168 EGU General Assembly 2024) which dated the site using a method known as cosmogenic dating. It found its was ancient: "417 ± 82 ka, which is at least 300 kyr earlier than the previously documented earliest human presence north of 60 degrees."

Unsurprisingly, John Janssen is well aware of the implications of this finding regarding the occupation of Siberia at an early date, and the possibility that these people reached Beringia, crossed Bering Strait, and populated America 400,000 years ago. Janssen considers it feasible, and mentions it, as you can see in this video (starting at 21:50 min), where he presentatst the paper at the EGU 2024 conference. The following image is a still from the Video, and its text is "DIRING YURIKAH, Arctic Siberia, •61°N, limits of homo erectus? •early entry to North America?"

Video still, J. Janssen presentation. Notice the text! which reads: "Early entry to North America?"

In this video, Janssen describes his work on dating ancient sites in Eurasia using the cosmogenic method (that measures the concentrations of rare isotopes that are produced when cosmic rays hit rocks on the surface of the soil. The longer they are exposed, the higher the concentration, which serves as an indicator of its age).

But, at 25:27, the video gets interesting, when discussing the Siberian sites, so close to the Arctic, and America, Janssen states that:

"at the second site Diring we find humans very far north very much earlier than previously thought now nothing older than about 45,000 years ago has been reported from a range of Arctic sites closer to the Arctic Ocean and we see two dimensions to this. Firstly once Out of Africa around about 2.5 million years, say, humans moved Eastward remarkably quickly people were already at Shang Shen as you can see there in the map on the L Plateau by around 2.1 million and they reached Java in the tropical southeast Asia by around 1.5 million years ago now by this time humans were colonizing vast areas of mid to low latitude Eurasia and exploiting habitats as diverses temperate grasslands and tropical rainforests but then it took another million years or more quite a bit more for people to move as far north... and the other point to note here is that while of course there was still around 2,000 km from the Bering Strait it remains possible that people crossed in into North America well before the earliest widely accepted timing which at this point is still around about four 14,000 years ago now I should add there's there's not yet any genomic support for this early colonization idea so it seems that if any very early groups did cross uh into North America they failed to leave a genetic Trace in other words they they must have gone extinct. So what could have motivated these intrepid people to migrate into the chilly Arctic around 400,000 years ago here's one explanation of course earth's climate is always fluctuating and we think humans exploited a time of extraordinary warmth in the Arctic during what we call Super interglacial stage 11 that's this gray band shown in the plot there 9 and as shown by the green spike in the biological productivity in the Arctic there was really no better time in the past 1 million years to do so and this timing is also very interesting for another reason 400,000 years ago coincides with the suggested split in the neander and denisovan lineages. Denisovans are another yet another kind of archaic human and it's been shown by others that there probably exists a super archaic species known not from fossils but from DNA found in the sediments at the basal sediments of the Denisova cave in in the Altai. So I said before that we don't really know, uh, who these people were but there is an intriguing possibility that the Diring migrants were actually a group of archaic humans, uh, predating the Denisovans whose ancestry we only know thanks to work on the denisovan genome."

I am thrilled that a mainstream scholar suggested that Homo erectus people moved across Bering and entered America around 400,000 years ago. The lack of genetic imprint in the current Amerindians may not mean that they went extinct. Perhaps they left their admixed genes in the Native Americans but the "Great Dying" wiped this signal away when over 90% of the natives died following the contact with Europeans after 1492.

Other Scholars Who Have Suggested an Early Peopling of America

My research into Siberian sites led me to discovering some Russian academics and archaeologists mostly unknown to Western mainstream media. Sure, Western specialists in this field must know them, but I haven't seen them cited in the papers I have read about the subject, so maybe they are dismissed.

One of these scientists is Yuri A. Mochanov. I came across a review of his book Archaeology, the Paleolithic of Northeast Asia, a Non-Tropical Origin for Humanity, and the Earliest Stages of the Settlement of America, that he coauthored with Svetlana A. Fedoseeva, Richard L. Bland, and Roy L. Carlson. The review can be accessed in the Canadian Journal of Archaeology (Reviews, Vol. 32, No. 2 (2008), pp. 285-288. https://www.jstor.org/stable/41103634). The reviewer, Christy G. Turner II, mentions that "In 2001, I was much impressed, but not convinced, by Mochanov's arguments for a much earlier colonization of the New World than Clovis-era people. This discussion lasted long into the night in an Irkutsk hotel room, with Olga Pav- lova translating and Svetlana Fedoseeva, Mochanov's wife, offering frequent comments... Mochanov and Fedoseeva's work at Diring was the first to demonstrate that hominids were in Siberia long before Neandertals and modern humans arrived. Various dates for Diring and the chopper-chopping tool nature of the Diring artifacts hint at groups of East Asian Homo erectus roaming far north of those whose remains were found at the Lower Cave of Zhoukoudian near Beijing, China (about 40° N latitude)."

Feidel S., 2000 cites Mochanvov and then elaborates on his hypothesis of an early peopling of America:

"Yuri Mochanov, have been regarded skeptically, but thermoluminescence dates now suggest an age between 260,000 and 370,000 B.P.for this site, at 61°N latitude (Waters et al., 1997). If Middle Pleistocene hominids were capable of survival so far north, what would have prevented them from crossing Beringia and entering the Americas at a comparably early date (Butzer, 1991, p. 140)? Perhaps Homo erectus did get into the New World, but there is no acceptable archaeological evidence of a mid-Pleistocene human presence. However, Bryan (1978) photographed and described a poorly provenienced H. erectus-like cranium that subsequently disappeared from the Brazilian museum, where it had been stored. [see my post on this skull and also an article by Bryan, 1984, with pictures of the skull] Also in Brazil, a few alleged pebble tools have been reported from Level IV of Esperança Cave, associated with fossil bones dated to ca. 295,000 B.P. by the uranium–thorium method (de Lumley et al., 1988; see Lynch, 1990, for a skeptical assessment). If 250,000-year-old human occupation sites exist in the Americas, they should be as recognizable and recoverable as Old World sites of this age... there has been little controversy about Australian sites with relatively crude toolkits dating earlier than 30,000 years ago, Beaton (1991, p.213)..."

Regarding this final comment, I must point out that archaeologists in America are skeptical about ancient sites, they don't look for them, and ignore them or consider the tools geofacts or made by monkeys (see Coutouly, 2021 as an example). This has been pointed out by archaeologists like Boëda, 2014 who notes that "All sites predating 13,000 years ago are rejected, including by the discoverers themselves. This rejection applies equally to sites in North and South America, with arguments that the artifacts are not of human origin and/or that the stratigraphy is inconsistent and/or that the dating is insufficient, etc. The paradigm is all-powerful. Perhaps most surprising is that the scientific criteria required to validate the oldest remains are far from being as systematically applied to more recent sites. Similarly, upon reading these criticisms, it appears that some of them stem more from a principled opposition to the dominant model than from a scientific discussion presenting arguments and counter-arguments." (I have already posted about the opposition by Clovis-first supporters against older sites and an early peopling of America).

Regarding the remark by Beaton, 1991, his work compares the peopling of Australia and America, the attitudes of archaeologists in both regions, and discusses the different populating strategise. He is an inmpartial observer, not influenced by the Clovis notions, he is critical in his observations, and remarks that "The idea of truly Early Man in the Americas is an exciting one, as it would imply immigration of pre-sapiens Homo and the very strong likelihood of failed colonization and the first evidence for the extinction of Homo on a continental-sized land mass. For the uncommitted observer, however, as interesting as such biogeographic phenomena might be, they do not in themselves make a case for Early Man in America, and the presentation of evidence in support of Early Man is itself not convincing." I agree, strict methodology, and structuring the evidence is critical in supporting and building the case for a very early peopling of America. Borrero, 2015 admits that "Sadly, information for South America is still not always efficiently produced. Ambiguous but ambitious claims from places like Arroyo Vizcaíno, in Uruguay, or Vale da Pedra Furada in Brazil, are still prominen."

Beaton also puts forward an intelligent question that is thought provoking: "Australia and the Americas... were the recipients of the last continental colonizations. This occurred at roughly the same time in human history, and the source for the colonists was roughly the same. Yet, in the space of 40 (or so) thousand years, these continents became the stages for the playing out of very different cultural evolutionary trajectories. It is not a trivial question to ask how this came about.
In the Americas, archaeologists appear to take cultural differentiation at face value and do not question how it might be that in the space of a few hundred miles Great Basin hunters remained so apparently distant in cultural morphology from the fishers of the northwest coast. While the answer might seem terribly obvious that living in a high desert is quite a different matter from living on a very wet coast, Australianists could point to equally wet-dry environment zones, of equal nearness, where no such cultural differentiation occurred. Australianists might view their prehistoric record as indicating distinctive regional cultural differences, but the scale of these differences is intracontinental and takes on a very different coloration when compared with complexities in cultural morphologies in the Americas. One research problem that would appear to benefit greatly from an intercontinental perspective is that of colonization. Questions relating to foraging patterns, colonizing strategy, population history, and cultural evolution may be better phrased, and ultimately understood, for each continent with consideration of the other."

Beaton points out the incongruences: "Australianists will be equally impressed by the lack of credible pre-13,000-15,000 B.P. sites in the Americas. But if claims for sites of such an age are to be preferred by the "Early Man" and "pre Clovis" schools, then does this imply Homo erectus in the New World and extinctions of some early colonists? And how can it possibly be that so many of the claims for early dates come from sites in South America? Australianists might also be interested to hear from the American conservative school on the subject of how it is that in the space of only 13,000-15, 000 years the Americas, at the continental scale, have witnessed such extraordinarily high degrees of cultural experimentation and differentiation. What factors might account for this? Population, environment, unrestrained social vitalism?"

This criticsm prods both Clovis-firsters and those supporting a pre-Clovis peopling of America to up their game, improve their methods, strategies, and review or revamp their hypothesis.

The diversity of languages is a great point (See my posts on this matter), how did America develop such a variety in such a short span of time?

Regarding pre-sapiens presence, almost all genetic studies are below par. They usually include proxies for genuine Amerindians with people of mixed origins like a Peruvian from Lima (PEL), Colombian from Medellin (CLM), Mexican from Los Angeles (MXL), or a Puertorican (PUR) which also carry European and African admixture. Some studies ignore America altogether considering it recently populated. Neanderthal and Denisovan introgression is assumed to have been brought from Asia. The alternative, that Neanderthals or Denisovans reached America and admixed there with modern humans is not even considered. Conclusions are therefore based on limited data, tainted data, or prejudiced hypothesis. Every paper about Amerindians, their genetics, and diseases always points out their recent origin and European and African admixture. I doubt that any scientist has tried to identify markers that could have introgressed into genuine Amerindians before the European discovery of 1492, and the slave trade from Africa that began shortly after. If we can pinpoint bases in our DNA strands inherited 30,000 years ago from Denisovans, that in turn added some bases they got from mating with H. erectus, how can't we distinguish between recent and ancient European or African admixture?

And when it comes to the sites themselves, just one look at the scale of excavations undertaken in Siberia at the Diring Yuirakh site, moving several meters of topsoil, or the deep bit dug at Karama, I insist, once again, that nobody digs deep enough to find Early Pleistocene sites in America.

Mental blocks and prejudice also damage the cause of an early peopling of America. For instance, take the folliwng comment by Borrero, 1991: "ancient Korean industries have been invoked to justify the morphology of the material recovered in northeastern Brazil. The argument maintains that "The cobble industries that persisted in East Asia for more than a million years reflect original technological solutions" (Boéda et al. 2013: 446) and that the case of Boqueirão in Brazil is similar. One problem with this argument is that it was not Homo sapiens who produced the cobble industries throughout that period, which implies a completely different reality (Dennell 2009; Rabett 2012). Ultimately, the comparison with Korea is irrelevant." As you can appreciate Borrero does not admit that cobble-making non-sapiens people could have reached America and used this lithic industry in Brazil. So, yes, the comparison with Korea is relevant.

Returning to Butzer, 1984 he admits that it was "techincally" feasible for humans to have moved "from Asia into more productive regions of the New World for tens of millennia prior to 30,000 B.P." so the idea itself is acceptable. The problem is the evidence: "But the coeval record of prehistoric settlement in eastern and northern Asia is poor (Aigner 1981, 1984; Wu and Olsen 1985; Ikawa-Smith 1978; Aikens and Higuchi 1982; Larichev et al. 1987), and there still is no convincing record of such antiquity in Canada or the United States." He goes on, accepting the possibility of a Mid-Wisconsinan (~50-25 kya) entry into America "Human groups, physically less advanced than modem Homo sapiens peoples and with an unsophisticated middle Paleolithic (Mousterian) technology, settled the European tundra to within close proximity of the ice fronts in both western and eastern Europe (e.g., Butzer 1986; Hoffecker 1987). Several late Acheulian sites were already located in tundra environments. Sites of such age have been found in caves, in the former floodplains of small streams, as well as in valley-margin deposits of colluvial loess. Unless we are unwilling to ascribe similar mental and cultural capacities to East and North Asian peoples during early and mid-Wisconsinan time, it is possible, even plausible, that they did penetrate the New World under harsh climatic conditions."

Butzer offers many interesting tips on locating older sites, and calculates how scarece they are. It is an interesting paper that is worth reading.

Closing comments

It is encouraging to see that the tide is changing. An early presence of humans (Denisovans or even Homo erectus) in Siberia half a million years ago shows that they were capable of living in the harsh and freezing conditions of the northeastern limits of Eurasia. At that time, America and Asia were linked (during the successive ice ages) by viable land bridges with fauna that would have enabled them to walk across it and, leaving Asia, enter America.

The high prevalence of a Denisovan genetic imprint in Amerindians may be a sign of their survival over hundreds of thousands of years in the New World, and their intermingling, within the Americas, with the Homo sapiens latecomers.

My next post will look into this possibility

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2026 by Austin Whittall © 

Japanese and pre-Clovis North American stone points are similar, and 20 ky old

Continuing with the Clovis people, and their lanceolate stone points (leaf shaped, without a stem, with a flatter, concave tip opposite its point), a paper published in Science by Madsen et al., 2025 reported that similar stone-knapping technologies were used in Japan around 20,000 years ago and in North America 15,000 to 16,000 years ago, producing stemmed stone points. This occurred before the Clovis-style lanceolate points appeared.

This is the paper: David B. Madsen et al., Characterizing the American Upper Paleolithic. Sci. Adv. 11, eady9545(2025). DOI :10.1126/sciadv.ady9545. I had already posted about it in the context of an early peopling of America, today I will refer to it in the context of Clovis "late" and also an even earlier arrival date into America before 27 kya.

The paper studied tools found in ten different ancient pre-Clovis sites (including Friedkin and Page-Ladson mentioned in my previous post) dating back to the North American Upper Paleolitic (AUP) and compared them with tools unearthed in Japan.

With some the exception of the Schaefer, Hebior, and White Sands sites, all the others share similar stone working technologies and are ancient: "Age estimates associated with the basal AUP components at these sites range between ~20,000 and ~13,500 cal yr B.P. Because the 10 sites are widely distributed across North America south of the ice sheet, the AUP populations associated with their occupations were also apparently widespread, albeit perhaps thinly. Given this wide distribution and the associated age range, we speculate that the initial occupation of lower-latitude North America likely occurred around 20,000 cal yr B.P."

This is interesting, widespread across the subcontinent 20 ky ago! The paper also questions the Beringian origin and the "standstill" hypothesis.

"... there are no known stone tool complexes in Beringia that are old enough and/or similar enough to be possible progenitors of AUP technology. All lithic tool assemblages in eastern Beringia postdate ~14,500 cal yr B.P., lack large core-and-blade production, and are characterized by a microblade technology and a small “teardrop-shaped” projectile point pattern that is not found in the AUP.
...
In other words, present speculation that ANA [Ancient Native American] populations and AUP technology originated in Beringia, e.g., (7, 8), is just that—speculation—and so we need to look elsewhere for a likely cultural progenitor of the AUP. The archeological record of the northwestern Pacific Rim’s Paleo-Sakhalin-Hokkaido-Kuril (PSHK) peninsula and its vicinities in continental East Asia is older than the AUP, is geographically most proximal to North America, and is therefore the more likely region where an AUP cultural progenitor may be found.
...
The distinctive technological features seen in Hokkaido LUP [Late Upper Paleolithic] lithic assemblages dating to between ~20,000 and ~16,000 cal yr B.P. provide some of the strongest clues potentially linking the cultural patterns of the LUP in the PSHK to the AUP. While we cannot yet determine whether the LUP populations on Hokkaido or elsewhere in the PSHK [Paleo-Sakhalin-Hokkaido-Kuril region] (or Beringia, for that matter) were directly genetically related to the First Americans, their technological lithic traditions do suggest potential cultural connections. "

Map showing the locations mentioned in the paperE. Fig. 1 in Madsen et al., 2025

Clovis period was short lived

Clovis points appeared ~13,275 to ~12,980 cal yr B.P. but "were largely abandoned by the end of the very short ~600 to ~250-year Clovis period" they were replaced by the Folsom style points.

Lack of Microblades hint at a very early date for the peopling of America: older than 27 kya

The theory sounds interesting, but there are some things that it does not explain. For instance, there are no microblades in among the AUP stone tools. Yet these are found in Northeastern Asia and Hokkaido in Japan in sites that are older than 20,000 years (Figure 9 in the paper shows that microblades first appeared 27 kya). The authors find this "intriguing" (because they are constrained by orthodox pre-Clovis dates for the peopling of America which do not contemplate very early dates). They suggest that microblades are an adaptation to the colder environment of Northern Asia (?). A simple explanation is that the first people to reach America did so before microblades were developed, in other words they did so over 27 ky ago.

And, unsurprisingly, the paper states that "Although the exact timing is uncertain, the ice-free corridor between the Laurentide and Cordilleran ice sheets appears to have closed by around 26,000 cal yr B.P. and remained impassable until after the appearance of AUP sites south of the continental ice sheets." This, in my opinion suggests that these people entered America before 26,000 years ago while the corridor was open (which coincides, more or less, with the 27 ky limit mentioned above). What other proof do you need?

But the paper, constrained by current orthodox timelines proposes a later migration along a coastal route 20,000 years ago and proposes the following dates and supporting literature:

"Praetorius et al., in a review of environmental conditions along the Pacific coast of North America, particularly variations in the strength of counterclockwise coastal currents, suggest that the most optimal times for a coastal migration during this period were between ~24,500 and ~22,000 cal yr B.P. and again between ~20,000 and ~19,000 cal yr B.P. Similarly, on the basis of an examination of faunal records from the same southern Alaska and Canadian coastal zone, Steffen concludes that glacial ice cover “probably hindered” migration starting between ~23,300 and ~20,000 cal yr B.P. and lasted until ~18,900 to ~17,700 cal yr B.P. Together, these studies conclude that conditions were optimal for a coastal migration into the Americas sometime about 22,000 years ago, a time estimate compatible with our archeologically based estimate of sometime shortly before ~20,000 cal yr B.P."

The authors also open the window for an earlier migration, by sea (as mentioned in my previous post on this paper) "Alternatively, the migration may have been rapid but also have occurred any time. By ~30,000 cal yr B.P., Upper Paleolithic seafarers were using sea-going vessels to access some of the outer islands in the Japanese archipelago, and were capable of negotiating the Kuroshio Current, one of the fastest in the world. This suggests that such experienced seafarers may also have been capable of handling adverse Pacific coastal currents. Either way, environmental constraints on the timing of the initial occupation of the Americas may not have been much of a factor."

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2026 by Austin Whittall © 

The Bering Land Bridge Emerged Much Later Than We Thought

The land bridge that emerges when sea level drops at the Strait of Bering has served as a corridor for animals to move between Eastern Asia and the Americas over the past 2 million years, and we assume that human beings used it to enter America coming from Asia around 20,000 years ago. There is an additional use for the land bridge across the strait as a place where humans diversified during a "standstill" there creating the unique Amerindian genetic patterns, and also as a refuge during the height of the ice age when glaciers blocked their entry into America.

I don't buy the standstill (see this 2014 post), but you can read about it here, and a critique here.

The first to suggest the idea of Asians entering America by foot was the Spanish Father José de Acosta in 1590 (Historia Natural de las Indias), when the existence of Bering Strait wasn't even known, he proposed that the "Indians" had reached America from Asia: "How did the first inhabitants of the Indies reach it… not by sailing the sea but by walking on land."

But when did this happen? According to a paper published in September 2025, not as early as we had suspected (Wanket, C., Kodama, S., Oppenheimer, J., Cocker, S., Steigerwald, E., Froese, D., Shapiro, B., Pico, T., & Farmer, J. (2025). Converging evidence constrains late pleistocene bering land bridge history. Quaternary Science Advances, 19, Article 100292. https://doi.org/10.1016/j.qsa.2025.100292.

The Strait of Bering and surrounding seabed is quite shallow, roughly 53 m deep nowadays (180 ft.), and it has emerged and been flooded as sea levels rise and fall. The main cause of sea level variation is global cooling and warming: when the world cools during the ice ages, snowfall accumulates producing vast ice fields across the northernmost and southernmost parts of the globe, the water in the ice comes from the sea, causing its level to drop. When the climate heats up (like it is doing nowadays -Global warming) the ice melts and sea levels rise: "Global average sea level has risen 8–9 inches (21–24 centimeters) since 1880. In 2023, global average sea level set a new record high—101.4 mm (3.99 inches) above 1993 levels." (https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level)

When the sea level is low, a dry area links Asia with America: The Beringian land bridge.

These sea level fluctuations imply that the Beringian land bridge or BLB formed many times over the past 2,000,000 years and formed during the cold spells at the peak (Maximum) of these Ice Ages, the most recent one was the Last Glacial Maximum or LGM. Warmer interglacial periods submerged that route and would have required navigating across a short stretch of sea between Asia and Alaska.

This paper finds that the evidence it analyzed "support the idea that the BLB was last exposed shortly before the LGM, over 30 kyr later than traditionally assumed."

This narrows the window of opportunity for the migration of modern humans into the New World to between 36,000 and 12,000 years ago, the last time that the BLB emerged.

And also ignores the fact that humans could have navigated across the ocean between Asia and Oceania to America at any time since the earliest Out Of Africa migrations of H. sapiens (~177-194.000 years ago - Source).

Older Bridges

But this is only the latest land bridge. There were many more in the past.

The Wisconsin glaciations (12 – 110 ky) were one of many that occurred during the last half million years. Other recent glacial events are the Illinoian (120-200 ky) and pre-Illinoian (300/380 – 455 ky). Regarding fauna migration, an ancestor of both black and brown bears colonized the Siberian steppe about 3.5 Ma., and shortly after. the black bears migrated into America across Beringia. They were followed by the brown bears 300 ky. The cave lion ancestor of the American lion (puma) entered America through Beringia during the next-to-last (Illinoian) period. In an inverse path across Beringia, horses, who originated in America, dispersed across Eurasia 1 Ma., and woolly mammoths from the New World colonized Eurasia 60 ky. Could this mean that even earlier arrival dates for humans are possible?

Yes! The Bering Land Bridge formed many times. The problem lies in the timing of an Out of Asia event. Current evidence suggests humans reached Northeastern Asia some 40,000 years ago, so they could have only entered America during the LGM. But, other hominins have lived in Asia over the past 1.8 million years, they could have moved into America using an ancient BLB.

Beringia Land Bridge. Source

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2025 by Austin Whittall ©