David Reich's take on the Y population and Australasians

The mysterious and ancient ghost population known as "Y" Population mentioned in yesterday's post (and in several other posts over the past years) was explored in depth by Harvard geneticist, David Reich in his 2018 book Who We Are and How We Got Here: Ancient DNA and the New Science of the Human Past 🔓.

In Chapter 7 (starts on p. 155), dedicated to the original ancestors of the Native Americans, Reich explains the theories and timing of the peopling of America based on current archaeological and genetic data.

Reich tells how the one wave peopled South America mutated over the years, and now we believe that at least four separate migrations led to the current makeup of Native Americans. Of relevance is the section starting on p. 176 that looks into the Y population.

The basics are the following: Walter Neves was the first to propose (see post) base on skull morphology, that ancient Brazilian paleoindians, like those found in Lagoa Santa were very similar to those of Australian aboriginals and Melanesians from Papua New Guinea.

Fig 21 in Reich's book, original caption reads: Despite extraordinary geographic distance, populations in the Amazon share ancestry with Australians, New Guineans, and Andamanese to a greater extent than with other Eurasians. This may reflect an early movement of humans into the Americas from a source population that is no longer substantially represented in northeast Asia.

This was very controversial, and opposed by the mainstream anthropologists. However, Pontus Skoglund investigated this possibility and after looking into the genetics of different native people, "found two Native American populations, both from the Amazon region of Brazil, that are more closely related to Australasians than to other world populations... Skoglund found weaker signals of genetic affinity to Australasians, but still probably real, in other Native American populations ringing the Amazon basin. He estimated that the proportion of ancient ancestry in these populations was small—1 to 6 percent—with the rest being consistent with First American ancestry."

This pattern appeared not only in Skoglund's data (by the way, Skoglund was working with Reich as a postdoctoral student), but in other data sets collected by other scientists. Furthermore, they also showed that it wasn't a recent admixture with people from Australia or Papua New Guinea, nor the result of Polynesians carrying these alleles across the Pacific to America.

The remarkable findings are that:

• Similar yet not closely related: "while Amazonians had their strongest affinity to indigenous people from Australia, New Guinea, and the Andaman Islands (compared to East Asians as a baseline), they were not particularly close to any of them"
• It was highest among the Suruí, Karitiana, and Xavante groups, and almost absent elsewhere: "We found little or no Population Y ancestry in Mesoamerica or in South Americans to the west of the high Andes. We also did not detect Population Y ancestry in the almost thirteen-thousand-year old genome of the Clovis culture infant from the northern United States, or in present-day Algonquin speakers from Canada. The Population Y geographic distribution is largely limited to Amazonia, providing yet more evidence for an ancient origin" Reich attributes this limited distribution to an "original pioneering population that was once more broadly distributed and was then marginalized by the expansion of other groups."
• Two groups of Native Americans with skulls similar to those of Neves' Paleoindians were tested by other researchers, they were Pericués of Baja California, and Fuegians in Argentina, however, neither group carried the signal of Population Y alleles.

This evidence suggests different population possibilities to Reich: (1) Population Y reached America first, spread across the continent and later, when the "First Americans" (actually, the current ones, but not first, they were second) arrived they displaced and replaced the Population Y people "either completely or only partially, as in Amazonia. Population Y ancestry may have survived better in Amazonia than it did elsewhere because of the relative impenetrability of the Amazonian environment." So, in the Amazons the original Population Y was not razed, but admixed gradually with the newcomers.

The current levels of Population Y ancestry in the Amazonians may be small (~2%), Reich states that the impact of the ghost populations should not be dismissed. Reich proposes a second theory (2) in which he supposes that the Population Y people as they walked across Asia and Siberia into "northern North America where the ancestors of First Americans were also living. It is likely that Population Y was already mixed with large amounts of First American–related ancestry when it started expanding into South America. If so, then the ancestry derived from a lineage related to southern Asians is only a kind of “tracer dye” for Population Y ancestry—like the heavy metals injected into patients’ veins in hospitals to track the paths of their blood vessels in a CT scan. Our estimate of around 2 percent Population Y ancestry in the Suruí is based on the assumption that Population Y traversed the entirety of Northeast Asia and America without mixing with other people it encountered. If we allow for the likelihood that there was mixture with populations related to First Americans on the way, the proportion of Population Y in the Suruí could be as high as 85 percent and still produce the observed statistical evidence of relatedness to Australasians. If the true proportion is even a fraction of this, then the story of First Americans expanding into virgin territory is profoundly misleading. Instead, we need to think in terms of an expansion of a highly substructured founding population of the Americas. The history and timing of the arrival of Population Y in the Americas is likely to be resolved only with recovery of ancient DNA from skeletons with Population Y ancestry."

So, in this second scenario, the Y Population isn't the original one, instead it was part of the First People reaching America, in a very highly structured population which somehow (Reich does not explain the mechanism though!) had already admixed with other Native groups, yet did not leave any signal in North America or Central America, or anwyhere other than the Amazon region.

I agree that further studies are needed, and finding Population Y remains will be of capital intererst, but also, we need a theory proposing a clear mechanism, other than Bottlenecks and genetic drift, to explain how the Population Y signal was erased, and is absent among present day Amerindians all across America —except for these three Amazonian groups.

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

Denisovan admixture within America?

Last may I published a brief post about a paper by Castro e Silva et al., (2026). The evolutionary history and unique genetic diversity of Indigenous Americans. Nature. https://doi.org/10.1038/s41586-026-10406-w. The paper is an in-depth study of South American natives' genetics, the three waves that peopled the subcontinent, and the "remarkable allele sharing with Australasian populations, probably originating from an ancient admixture event and partly maintained by selection for more than 10,000 years." It attributes this permanence across ten millennia because this admixture was positively selected for due to benefits these alleles provided to those carrying them.

Archaic Introgression

I re-read the article and took note of the part that says that the Australasian signal is not the result of an archaic introgression, which means that Denisovans didn't share these same genes with Oceanian and American natives, there were different groups admixing with each population. The paper states: "Furthermore, we identified candidate regions of adaptive archaic introgression from Neanderthals and Denisovans that contribute to functions related to immunity, metabolism and epidermal integrity, thereby reinforcing the role of archaic alleles in shaping the evolutionary trajectory of non-African populations. Importantly, our data indicate minimal overlap between genomic regions with Australasian affinity and those introgressed from archaic hominins, supporting the interpretation that these signals represent distinct evolutionary phenomena."

Australasian signal

The Australasian signal in Amerindians is very very peculiar, it has a high prevalence in some groups that live in the Southwestern Amazon region and Chaco (these groups are the Awajún, Ayoreo, Guarani, Karitiana, Sirionó, Suruí, and Tsimané). This is known as the introgression from a "Y" population, or Ypykuéra (a Tupi word meaning "ancestor") which is a "ghost lineage" of ancient Amerindians with a high Australasian genetic content.

The paper confirms that the distribution of Australasian "alleles" is not uniform, it shows a "partially discontinuous spatiotemporal pattern" which suggests, according to the authors that "this ancestry was present during the initial peopling of America." It is also very ancient because the paper finds that Amerindians "diverged from other continental groups between about 70,000 and 15,000 years ago."

The paper states that isolation of these Amazonian groups that carry the highest frequencies of these introgressed alleles and their inbreeding and small population sizes are all factors that led them to have such a high prevalence of them. However, I wonder if another factor was at play: Denisovans lived in that region and encountered humans there, admixing in that area with them. After all it is a kind of cul-de-sac in the Amazonian rainforest nowadays, why wouldn't it have been one for the Denisovans? They also seem to have thrived in the jungles of Indonesia, and the Philippines in Southeast Asia.

The comparison between different groups within America, outside of America, and archaics, didn't detect any "correlation... between Australasian and Neanderthal... or Denisovan affinity... By contrast, Neanderthal and Denisovan affinities were strongly correlated... consistent with homogeneous archaic ancestry in the founding populations."

This is interesting because the Australasian signal is independent from the two archaic introgressions. This suggests that the Denisovans and Neanderthals that admixed with the first Amerindians were different from those who admixed with Australasians (including the Onge people and the Hòabìnhian people from Laos).

The authors wondered if the Australasian-Amerindian similarity was due to "shared archaic ancestry" but when the checked the introgression from Denisovans and Neanderthals in both groups, they found a "minimal overlap of 0.4%, corresponding to 11 genes/genomic regions... This minimal overlap indicates that the Ypykuéra ancestry is unlikely to have been derived from a known archaic hominin." (This is not clear, what do they mean by "a known archaic hominin"?)

The paper did find a "shared ancestry component between Indigenous Americans and Australasians that extends deep into the past." So this shared ancestry probably came from a similar modern human group, yet, as mentioned further up, the ancestors of the Amerindians split from other H. sapiens 15 to 70,000 years ago. I favor the older date. But, intriguingly, these people did not admix with the same Denisovans or Neanderthals that the Australasians bred with!

This could be explained by a split in this basal Homo sapiens: one group went into Australasia and admixed there with a group of Denisovans, the other headed north into East Asia mixing with other Denisovans, and eventually reached America. However, why is there no presence of other East Asian signals in Amerindians? This leads to a second alternative: the admixture event between Denisovans and the modern human ancestors of Amerindians took place inside America?

The map below outlines this possibility, with the Denisovans splitting from the Neanderthals somewhere in the South Caucasus, and moving into East Asia along different routes, a northern one to Altai, and then Tibet and East Asia, another along South Asia, and South East Asia into the Philippines and Papua New Guinea. Another hypothetical route could have led them across Siberia into America. Their last stand was in the Tropical Amazon region. They seemed to thrive in all types of climate, from icy siberia and Altai, to the highlands of Tibet, and the jungles of Sundaland and Sahul. America offers all of them: Cold Alaska, Canada and Northern USA, Patagonia, high mountains and plateaus in Bolivia and Peru, as well as along the Andes in Chile and Argentina, and of course the Jungles east of the Andes from Colombia, Venezuela and Bolivia to Brazil, Paraguay and Argentina.

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

On the Australasian imprint in Paleoindians (Part 2)

See part 1 here

This post continues my analysis on how did the Australasian genetic imprint (from Southeast Asia and the Andaman Islands) reach the ancient Amerindians and current tribes in the Amazon and NW Peruvian coast without leaving any traces in the North American Natives, ancient North Amerindian remains, or their Beringian ancestors.

I thought it would be pretty straightforward, but it isn't. The genetics of the Late Pleistocene in Asia are not simple. There were several groups there around 50,000 years ago, and the current populations don't reflect the situation at that time.

Assuming Out of Africa as correct, it seems that humans moved across Asia and diversified into different "Basal" populations.

Tianyuan Man

Genetic analysis of a male found in Northern China, close to Beijing, in the Tianyuan cave, confirmed he had 4-5% of Neanderthal introgression. He was dated at 41,000 years ago. "three South American populations—the Surui and Karitiana in Brazil (“Amazonians”) and the Chane in northern Argentina and southern Bolivia—share more alleles with the Tianyuan individual than other Native American populations do." (source), these Amazonians are the ones with the Australasian imprint. The paper adds that "we find that the Amazonians can be described as a mixture of other Native American populations and 9%–15% of an ancestral population related to the Tianyuan individual, the Papuan, or the Onge (SE 4%–10%)." So here we add another "ancient" Asian component to the Australasian imprint, the Tianyuan man's genes.

The paper reasons that "The fact that the Tianyuan individual, who lived in mainland Asia about 40,000 years ago, has affinities to some South American populations that is as strong as or stronger than that observed for the Papuan and Onge suggests that a population related to the Tianyuan individual, as well as to the present-day Papuan and Onge, was once widespread in eastern Asia. This group or another Asian population related to this group persisted at least until the colonization of the Americas and contributed to the genomes of some Native American populations."

A 2025 paper found that "Among individuals from continental Eurasia, we find the highest proportion of detectable Denisovan ancestry in Tianyuan (∼0.25%), while other pre-LGM individuals from Eastern Eurasia had lower levels of Denisovan ancestry, comparable to those of later East Asians and Siberians."

Onge and Hòabìnhian

The Onge from the Andaman Islands are Australasians, and their signal is found in the Amazonian tribes. They were part of a basal population in Southeast Asia, a 2022 paper includes the following map showing a possible entry route into the area, and the current levels of this ancient basal component. Note how high it is in some areas.

Basal Asians. Fig. 2 in Deng et al. (2022)

The paper continues: " We speculate this basal Asian (bASN) ancestry to be an ancient lineage... the bASN ancestry is negatively correlated with the Altai Neanderthal introgression in Asian populations... suggesting that the peopling of Asia might have occurred prior to the Altai Neanderthal introgression (directly or indirectly) to the modern human populations in this region." Which makes sense, the Neanderthals lived in the colder central and NW regions of Asia, and possibly in NE Asia. So the people that moved along the coast of Southern and SE Asia didn't encounter Neanderthals on their journey.

An extremely interesting paper by Silcocks & Dunstan (2023) on dispersal of humans and two strains of tuberculosis across Asia finds a similar distribution of ancient people in Asia, the basal one in SE Asia, a later wave in northern and central Asia. (map below from the paper).

!--image captions-->

Original caption: "Fig. 7: Our proposed model of human-Mtb co-expansion, including population dispersal trajectories, and the predominant Mtb and Y-chromosome lineages they carried.". Source

A paper published in Science by McColl et al., (2018) indicates that there are "at least four ancient populations [in Asia] The oldest layer consists of mainland Hòabìnhians (group 1), who share ancestry with present-day Andamanese Önge, Malaysian Jehai, and the ancient Japanese Ikawazu Jōmon." The paper includes the following map, which shows an even older migration (black arrows) heading norteast to Tianyuan and southeast into Sahul, Papua New Guinea and Australia. The Onge and Hòabìnhians split later (red arrows).

Original Caption: Fig. 4 Model for plausible migration routes into SEA. This schematic is based on ancestry patterns observed in the ancient genomes. Because we do not have ancient samples to accurately resolve how the ancestors of Jōmon and Japanese populations entered the Japanese archipelago, these migrations are represented by dashed arrows. A mainland component in Indonesia is depicted by the dashed red-green line. Gr, group; Kra, Kradai. Fig. 4 McColl et al.

A similar route is suggested by Larena et al. (2021) which analyzes the genetics of the Philippine population. It mentions a first wave of human beings that reachied Sundaland (at that time it was not submerged) and peopled Australia, Papua New Guinea, the Indonesian Islands, the Philippines, and Andaman Islands around 50,000 years ago. This basal group put the Negrito people in the Philippines. Below is Fig. 2A from the paper, where I have added these place names and the comment on the exposed continental shelf

This wave comprised "Paleolithic hunter-gatherer groups, linked genetically to the Basal Australasian branch of modern humans"" it led to the Negritos, PNG people and Australian Aboriginal people, and also, in Southern China to another basal group, shown in the image above, the "Basal East Asian".

These Basal East Asians could have moved along the Pacific coast, northwards into Japan, and the Siberian coast, reaching America with their Onge genetic imprint. Moving along the coast of North America they didn't leave an imprint in its interior. Then, when they reached South America they moved inland. Plausible, but strange.

I have not yet found a paper with a convincing explanation of the "Gap" in Beringia, ancient North American and Mesoamerican paleoindians and most of the later Amerindians in the continent.

False Signal?

A study published in 2018 by Posth et al. failed to find the Population Y signal:

"We tested for this signal in the ancient South American individuals with statistics of the form f4(Mbuti, Australasian; X, Mixe or ancient South American), and while we replicated the originally reported signal when X was present-day Karitiana or Surui, we could not detect a signal when X was any of the ancient South Americans (Table S6). We also studied the statistic f4(Mbuti, Tianyuan; Ancient1, Ancient2) to test if any ancient individual is differentially related to Tianyuan (Yang et al., 2017), but no statistic was significant (Table S6). We finally applied qpWave to all pairs of South American groups, testing whether they were homogeneously related to a set of diverse non-Native American outgroups (Mbuti, Han, Onge, French, and Papuan) and found no pair of ancient South Americans that consistently gave significant signals (p < 0.01), as expected if all the ancient South Americans we analyzed derived from the same stem Native American population (Table S6). Our failure to find significant evidence of Australasian or Paleolithic East Asian affinities in any of the ancient Central and South American individuals raises the question of what ancient populations could have contributed the Population Y signal in Surui and other Amazonian groups and increases the previously small chance that this signal—despite the strong statistical evidence for it—was a false-positive. A priority is to search for the Population Y signal in additional ancient genomes."

Another paper searched for the Population Y signal using f4 statistics: f4(Mbuti, Papuan/Onge/Australian; present-day Mexicans, ancient Brazilians). The authors noted that:

"The only ancient Brazilian group showing significant affinity to Onge, compared with present-day Mexicans, is the JabuticabeiraII_~2400BP group. The signal is mainly driven by one individual (JBT009—burial 38), but it remains for the entire group even after the exclusion of JBT009. Similarly, there is significant genetic attraction between Onge and one individual from the Cabeçuda_3200BP group (CBE004—burial 15), while all other tests do not reach values close to significance (Supplementary Data 7). However, no evidence of the Population Y signal is found in the recent Amazonian individual Palmeiras Xingu_500BP, despite the fact that this ancestry was first described in present-day Amazonian populations; or in Capelinha_10400BP, despite its association with the paleoamerican cranial morphology. We further tested the presence of differential affinity of ancient Brazilian individuals to present-day Papuans, Onge and Australians, as well as the 40,000-year-old Tianyuan genome-wide data from China using f4 statistics of the form f4(Mbuti, Papuan/Onge/Australian/Tianyuan; Ancient Brazilian A, Ancient Brazilian B). Only the JabuticabeiraII_~2400BP group reaches significant attraction to both Onge and Papuans, and only in comparison to LapaDoSanto_9600BP (ref. 63). This suggests either that the Population Y signal is equally widespread in most tested ancient individuals from Brazil or that previously reported attractions to non-American ancestries are exacerbated by the use of present-day Mexican populations in comparison to ancient groups (Supplementary Data 7)."

Modern Mexicans are a mixture of European and North American native people. It is reasonable that they are different from secluded Amazonian natives. The Mixe natives are North American, which lack this Population-Y signal. It does not appear to me that they "exacerbate" the population Y signal.

Posth et al. didn't detect it among the ancient samples they used, this does not mean it is a false positive, perhaps their sample did not include the members of this first peopling wave which was erased by later "ancient" people via Beringia, with Siberian genetic imprints.

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

On the Australasian imprint in Paleoindians (Part 1)

See part 2 here

In this post I am sharing text from a paper published in 2022 (Silva, M. A. C. e ., Ferraz, T., & Hünemeier, T.. (2022). A genomic perspective on South American human history. Genetics and Molecular Biology, 45(3), e20220078. https://doi.org/10.1590/1678-4685-GMB-2022-0078. Online) that summarizes the current (in 2022) knowledge about the peopling of South America, and provides early dates and information on the Australasian genetic imprint found there:

Taken together, the current archeological evidence supports that humans were present in the Americas at least 20 ka BP during the peak of the LGM (Ardelean et al., 2020; Bennett et al., 2021). Although the identity of these first Americans remains an open question, genetics has given us some insight into who they may have been, as revealed by the faint signal of shared ancestry with modern-day Australasian peoples (Skoglund et al., 2015; Castro e Silva et al., 2021). This data supports the hypothesis that the initial settlers were more closely related to the ancestors of modern Australasians than to those of East Asians and also implies that their contribution to post-LGM Native American populations was mostly absent and seldom minimal. In this scenario, these first human groups to reach the continent would have been later replaced by the ANA descendants, starting by the end of the LGM, and only rarely would have admixed with them. Furthermore, our recent findings show a lot of variation within populations (Castro e Silva et al., 2021), which suggests that some of these first Americans could have lived in relative isolation until very recently when admixed with SNA populations. Furthermore, most of the genetic contribution from these early ancestors might have been erased by the intense population dynamics during the Holocene and by the successive inflows of distinct SNA groups in the case of South America (Posth et al., 2018).
Considering that continental glaciers completely blocked northern North America throughout the LGM period, an early settlement of the Americas requires an alternate pathway. This alternative is provided by the so-called coastal migration theory (CMT) (Davis and Madsen, 2020), which proposes that the Pacific Rim shorelines were used as a route into the Americas from Asia by groups of humans adapted to a seaside lifestyle, likely based on the exploitation of the resourcefully rich environments of kelp forests present along both continents’ Pacific coasts (Erlandson et al., 2007). In that case, it could also help explain the absence of the Australasian signal in North America if the dispersal was rapid and mostly restricted along the Pacific coast, resulting in more significant population growth in South America at the expense of North America. Most interestingly new evidence points to the existence of a very large number of islands in the Bering Sea to the south of Beringia between 30 and 8 ka BP, named the Bering Transitory Archipelago (BTA), which would have greatly enhanced the availability of marine resources and also facilitated sea travel through more easily navigable and protected waters (Dobson et al., 2021).
Finally, some genetic and morphometric analyses of Northeastern and Southeastern Asians (NEA and SEA, respectively) provide some intriguing pieces of evidence on the origins of the Native American-Australasian connection. First, a link between the Onge and the ancient SEA hunter-gatherers, known as Hòabìnhians, is demonstrated by the genetic affinity between the Onge and two Hòabìnhians from Laos and Malaysia with approximately 8 and 4 ka BP (McColl et al., 2018), implying that the latter are closely related to the Onge’s ancestors. Second, morphological affinities between the Onge (a SEA population) and the NEA (Matsumura et al., 2019) support the hypothesis that a group closely linked to the Onge - thus also likely related to the Hòabìnhians - was involved in an admixture event with the ANA and thus responsible for the Australasian genetic affinity observed in indigenous Americans (Skoglund et al., 2015). There is also solid evidence that the distribution of modern-day Australasian and East Asian ancestors was significantly different across East Asia during the Pleistocene and that populations like the Jomon from Japan show very clear indications of a mixture of northern and southern Asian ancestries (McColl et al., 2018; Wang et al., 2020); this is particularly meaningful given that Japan is a likely candidate and the proposed birthplace of the First Americans in the CMT framework. These findings illustrate how important it is to comprehensively elucidate East Asian population history in order to grasp the full picture of the Americas’ peopling. "

Below is the map in Skoglund et al.'s 2015 paper regarding Australasian and Amerindian affinities.

Original image caption: heatmap of CHROMOPAINTER statistics. For non-Americans we display the symmetry statistic S(non-American; Mixe, Suruí & Karitiana) for donating as many haplotypes to Mixe as to Suruí & Karitiana. For the Americas we plot S(Onge; Mixe, American) for receiving as many haplotypes from the Onge as do the Mixe.. Fig 1 in Skoglund et al.

The Population-Y

Skoglund et al. 2015 paper discovered this Australasian signal. They write the following:

" we do find that a model where Amazonians receive ancestry from the lineage leading to the Andamanese fits the data in the sense that its predicted f4-statistics are all within 2 standard errors of statistics computed on the empirical data (Extended Data Figure 6; Extended Data Figure 7; Extended Data Table 3). These results do not imply that an unmixed population related anciently to Australasians migrated to the Americas. While this is a formal possibility, an alternative model that we view as plausible is that the ‘Population Y’ (we use ‘Population Y’ after Ypykuéra, which means ‘ancestor’ in the Tupi language family spoken by the Suruí and Kartiana) that contributed Australian related ancestry to Amazonians was already mixed with a lineage related to First Americans at the time it reached Amazonia. When we model such a scenario, we obtain a fit for models that specify 2%-85% of the ancestry of the Suruí, Karitiana, and Xavante as coming from Population Y (Figure 2). These results show that quite a high fraction of Amazonian ancestry today plausibly comes from Population Y. At the same time, the results constrain the fraction of Amazonian ancestry that comes from an Australasian related population (via Population Y) to a much tighter range of 1%-2% (Figure 2).
We have provided compelling evidence that a Population Y that has ancestry from a lineage more closely related to present-day Australasians than to present-day East Asians and Siberians, contributed a small fraction of the DNA of Native Americans from Amazonia and the Central Brazilian Plateau."

Onge people

You can see some Onge people in the following picutre (source):

These people in the Anadaman islands of the Gulf of Bengal, in the Indian Ocean close to both India and Myanmar, are among the oldest (if you accept the Out of Africa hypothesis) humans after H. sapiens left Africa, and lived in isolation on their insular territory.

Their dark African-like skin is convergent evolution to adapt to their tropical habitat.

How did it reach America and the Amazon?

A paper from 2021 analyzed the matter in depth (to validate its reality -the signal could have been an artifact in the tools used, that mistook a strong genetic drift in the Amazonian people it was found in, for an ancient Australasian imprint.

It confirmed it was a real signal: "Here, we show the Australasian genetic signal is present in the Pacific coast region, indicating a more widespread signal distribution within South America and implicating an ancient contact between Pacific and Amazonian dwellers. We demonstrate that the Australasian population contribution was introduced in South America through the Pacific coastal route before the formation of the Amazonian branch, likely in the ancient coastal Pacific/Amazonian population. In addition, we detected a significant amount of interpopulation and intrapopulation variation in this genetic signal in South America.."

The study found the signal not only in Amazonian Suruí and Karitiana, and also among people living on the NW Pacific Coast of Peru like the Sechura, Chotuna, and Narihuala. The authors conclude that "Our results showed that the Australasian genetic signal, previously described as exclusive to Amazonian groups, was also identified in the Pacific coastal population, pointing to a more widespread signal distribution within South America, and possibly implicating an ancient contact between Pacific and Amazonian dwellers."

But no explanation on how did these genes end up in South America. Yes, the current belief is that the predecessors of modern East Asians were related to the Onge, and that these people moved by boat along the sea, bypassing Beringia and reaching America first, where they were later diluted by successive waves from Beringia.

To be Continued in Part 2.

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

Ancient Australasian signal found in South American natives

A paper published earlier this year (Deep genetic affinity between coastal Pacific and Amazonian natives evidenced by Australasian ancestry. Marcos Araújo Castro e Silva, et al. PNAS April 6, 2021 118 (14) e2025739118; https://doi.org/10.1073/pnas.2025739118), suggest that the very early or even the earliest people to reach South America carried a genetic component that is not found in North or Central America, and that is linked to a "Y Population" the genetic signal inherited from this group (called "Y" after "Ypikuéra" or "ancestral" in Tupi language") is only found among Australasian people.

The paper reports that the Y-population signal originally found among Amazonian Amerindians is also found in natives from other parts of Brazil, and also in the Pacific coastal population of South America.

The authors write: "The best-fitted model showed that the Pacific coast is a mixed group of South American ancestry and a small non-American contribution associated with a sister branch of Onge, as also observed for Karitiana and Suruí. They suggest that the presence of this signal on the Pacific coast suggests that the original population reached the area following a coastal route.

The Onge are people that live in the Andaman islands, in the Bay of Bengal, dark skinned isolated people... and they are linked to South American natives.

Did they land in North America and Mesoamerica and die out? Did they bypass the northern part of the Americas and settle in the South?. The lack of this signal in the northern part of the continent is not explained in the paper.

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Patagonian Monsters - Cryptozoology, Myths & legends in Patagonia Copyright 2009-2021 by Austin Whittall ©