Where Does Language Complexity Evolve?

I'm not entirely sold on this article's conclusion about the circumstances in which language complexity evolves, at least not based upon the data presented, even though there is good evidence that large numbers of language learners tend to reduce grammatical complexity.

Polysynthetic languages are very common in the New World and just across the Beringian land bridge from it (which could also be connected to the Paleo-Siberian cases), suggesting that most instances of it could be derived from a common source creating a Founder effect. 

Also, while these languages are small and isolated now, this hasn't always been the case. Athabaskan-Eyak-Tlingit and Nahuatl, for example, historically were quite expansive and had lots of contact with other language families.

The second cluster is from Aboriginal Australians and Papuans who derive from the first wave of modern human migration Out of Africa and into Asia around the time of the Toba eruption. 

There is a third cluster in the Caucuses, involving just one of the language families there, which are associated with early migrants from the first wave of Fertile Crescent agriculture in the highlands of West Asia. 

There are apparently other instances in South Asia and East Asia.

A handful of major language expansions, none of which happened to be polysynthetic make up a huge share of all languages spoken today. These include the Indo-European language family, the Afro-Asiatic languages, the Bantu language family, the Dravidian languages, and the arguable Altaic language family. European and Chinese colonial empires further reduced the size of many languages (long after their features were well intact), for reasons unrelated to language complexity. 

There are polysynthetic or borderline polysynthetic languages listed in the following major language families: the Sino-Tibetan languages (seemingly all in the Tibetan-Burmo branch), the Austroasiatic languages (3 Munda languages in Northeast India), the Austronesian languages (5 borderline seemingly Formosan languages) 

If only a minority of pre-expansion languages were polysynthetic, it wouldn't be surprising if the main expanding languages didn't end up including them.

Significance

A global test reveals statistically robust support for the hypothesis that complex word forms are more likely to develop in isolated languages. Polysynthesis, where words are built from many units to convey complex meanings, is more likely to occur in smaller populations and less likely to occur with many languages in contact. By building a global database of polysynthetic languages and analyzing in a phylospatial framework, this study highlights the potential for macroevolutionary methods to test hypotheses about language evolution and contribute to long-standing debates in linguistics.

Abstract

Evolution of complexity in human languages has been vigorously debated, including the proposal that complexity can build in small, isolated populations but is often lost in situations of language contact. If it is generally true that small, isolated languages can build morphological complexity over time, but complexity tends to be lost in situations of language contact, then we should find that forms of language complexity that have evolved multiple times will tend to be associated with population size, isolation, and language age. 

We test this hypothesis by focusing on one particular form of morphological complexity, polysynthesis, where words built from many parts embody complex phrases. By assembling a global database of polysynthetic languages and conducting phylospatial analyses, we show that languages with highly complex word morphology are more likely to have small population sizes, less likely to occur with many other languages in direct contact, and have a greater tendency to be on long phylogenetically isolated lineages. 

These findings are consistent with the hypothesis that languages that evolve in isolation for long periods may be more likely to accrue morphological complexity. Polysynthetic languages also tend to have higher levels of endangerment. Our results provide phylogenetically informed evidence that one particular form of complex language morphology is more likely to occur in small, isolated languages and is prone to loss in contact.

Lindell Bromham, Keaghan Yaxley, Oscar Wilson, and Xia Hua, "Macroevolutionary analysis of polysynthesis shows that language complexity is more likely to evolve in small, isolated populations" 122(24) PNAS e2504483122 (June 12, 2025) (pay per view; but open access supplemental materials).

The languages counted as polysynthetic and borderline, according to the Supplemental Materials, are below the fold.

A Potentially Good New World Population Genetics Study Bumbled

A paper was published last year about the population genetics and historical genetics of the Blackfoot people. It compared a modest sample of Blackfoot affiliated genomes with other New World and Old World genomes. A small sample size isn't a big problem for a paleo-genetic study, however, because each individual's DNA has so many data points and generations of intermarriage in a fairly closed gene pool makes each individual highly representative of the population as a whole. But while the study does lots of things right, but makes a critical error in its analysis, which seriously detracts from the reliability of the analysis. This error arises from a weak review of the literature and deficient peer-review, which leads to an erroneous analysis.

The big problem with the paper is that it makes flawed assumptions about the peopling of the Americas. It relies on a model in which all Native Americans fit into two groups: Native North Americans (ANC-B) and Central and Southern Americans (ANC-A), and tries to determine where the Blackfoot people fit into that model.

The trouble is that the established paradigm is more complicated. While ANC-A is a valid and pretty much unified group that descend from basically Pacific coast route peoples in a primary founding population wave perhaps 14,000 years ago, Native Americans in North America have a more complex ancestry.

North American Native Americans have the lineages found in ANC-A (which results from a serial founder effect) and probably a least two other clades close in time to the initial founding era that spread into different parts of North America. 

Then, around 3500-2400 BCE, the ancestors of the Na-Dene people migrated to Alaska from Northeast Asia and admixed with pre-existing populations (their languages have remote but traceable connections to the Paleo-Siberian Ket people, whose language family is named after the Yenesian River in central Siberia) and are associated with the Saqqaq Paleoeskimo culture who also were the source of the Dorest Paleo-Eskimo populations (see also here and here) About 10% of Na-Dene ancestry is distinct from the initial founding population of the Americas.[2] The Na-Dene, like Inuits, have Y-DNA haplogroups that are specific to them and of more recent origin that the founding Y-DNA haplogroups of the Americas.[3].

And then, a final significant pre-Columbian wave with lasting demographic impact arrived from Northeast Asia, perhaps around 500s and 600s CE, and they are the ancestors of the Inuits (a.k.a. modern Eskimo-Aleut peoples) who have their roots in an Arctic and sub-Arctic population also known as the Thule. The 6th to 7th century CE Berginian Birnirk culture (in turn derived from Siberian populations) is the source of the proto-Inuit Thule people, who were the last substantial and sustained pre-Columbian peoples to migrate to the Americas.

A paper in 2020 refined and confirmed this analysis, and the 2024 paper even adopts its NNA v. SNA classification while failing to recognize the distinct temporal waves involved in the pre-Columbian peopling of the Americas.

See generally:

[1] Maanasa Raghavan, et al., "The genetic prehistory of the New World Arctic", Science 29 August 2014: Vol. 345 no. 6200 DOI: 10.1126/science.1255832.

[2] David Reich, et al., "Reconstructing Native American population history", Nature 488, 370-374 (16 August 2012) doi: 10.1038/nature11258

[3] Matthew C. Dulik, "Y-chromosome analysis reveals genetic divergence and new founding native lineages in Athapaskan- and Eskimoan- speaking populations", PNAS (May 29, 2012) doi: 10.1073/pnas/1118760109

[4] Erika Tamm, et al., "Beringian Standstill and Spread of Native American Founders", PLOS One DO: 10.1381/journal.pone.0000829 (September 5, 2007).

[5] Alessandro Achilli, "Reconciling migration models to the Americas with the variation of North American native mitogenomes", 110 PNAS 35 (August 27, 2013) doi: 10.1073/pnas.1306290110

[6] Zegura, et al., "High-Resolution SNPs and Microsatellite Haplotypes Point to a Single, Recent Entry of Native American Y Chromsomes into the Americas.", Mol. Biol. Evol. (2004) 21(1):164-175 doi: 0.1093/molbev/msh009

[7] Judith R. Kidd, et al., "SNPs and Haplotypes in Native American Populations", Am J. Phys Anthropol. 146(4) 495-502 (Dec. 2011) doi: 10.1002/aipa/21560

The critical problem with the paper is that Athabascans are a poor representative of Northern Native American lineages from the founding era ca. 14,000 years ago, because they have significant Na-Dene wave admixture, also shared, for example, with the Navajo, who migrated in turn migrated from what is now central to western Canada to the American Southeast around 1,000 CE (possibly, in part, due to the push factor of the incoming wave of proto-Inuits). 

In contrast, the vast majority of North American Native Americans have no Na-Dene or Inuit ancestry and are in population genetic continuity with one or more of the several founding populations of North America. Almost any other choice of a North American Native American comparison population would have been much, much better.

In contrast, the Karitiana are indeed representative (and the standard choice to represent) the ANC-A population.

It is entirely plausible that the Blackfoot are indeed from a wave of North American founding population that is under sampled and that their lineage is not represented in prior published works. 

Latin American indigenous peoples (and to a lesser extent and more recently, Canadian First Peoples) have, in general, been more receptive to population genetic work by anthropologists and Native American populations in the United States who have given these researchers the cold shoulder until very recently, due to a historical legacy that has understandably fostered distrust of people associated with the establishment in the U.S. including anthropologists. So, Native Americans in the U.S. are greatly under sampled.

But, because the thrust of the paper heavily relies on comparisons between Blackfoot DNA and Athabascan DNA with misguided assumptions about the Athabascan population histories entering into the calculations and analysis, it is hard to confidently extract reliable conclusions from that analysis. The Athabascan may be mostly ANC-B, but are probably the most divergent sample one could use to represent that population, particularly since no attempt is made to distinguish the ancestry components in that population. This seriously confounds the efforts to pin down the prehistoric time line.

A good quality peer-review should have caught this problem, but peer-review in practice is less effective than it is given credit for being.

Realistically, the only way to really do it right would be to withdraw the 2024 paper and replace it with a new paper that reanalyzes the Blackfoot genetic data by comparing it to a more suitable representative of North American Native American ancestry.

Studies of human genomes have aided historical research in the Americas by providing rich information about demographic events and population histories of Indigenous peoples, including the initial peopling of the continents. The ability to study genomes of Ancestors in the Americas through paleo-genomics has greatly increased the power and resolution at which we can infer past events and processes. However, few genomic studies have been completed with populations in North America, which could be the most informative about the initial peopling process. Those that have been completed in North America have identified Indigenous Ancestors with previously undescribed genomic lineages that evolved in the Late Pleistocene, before the split of two lineages [called the “Northern Native American (NNA)” or “ANC-B” and “Central and Southern American (SNA)” or “ANC-A” lineages] from which all present-day Indigenous populations in the double continent that have been sampled derive much, if not all, their ancestry before European contact. Specifically, the lineage termed “Ancient Beringian” was ascribed to a genome in an Ancestor who lived 11,500 years ago at Xaasaa Na’ (Upward Sun River) and named Xach’itee’aanenh t’eede gaay (USR1) by the local Healy Lake Village Council in Alaska. An Ancestor who lived 9500 years ago at what is now called Trail Creek Caves on the Seward Peninsula, Alaska, also belongs to the Ancient Beringian lineage. In addition, another Ancestor, under the stewardship of Stswecem’c Xgat’tem First Nation, who lived in what is now called British Columbia, belongs to a distinct genomic lineage that predates the NNA-SNA split but postdates the split from Ancient Beringians on the Americas’ genomic timeline. This Ancestor was identified at Big Bar Lake near the Frasier River and lived 5600 years ago. Thus, these previous studies of North American Indigenous Ancestors have successfully helped to identify previously unknown genomic diversity. However, the ancient lineages identified in these studies have not been observed in samples of Indigenous peoples of the Americas living today. Research in Mesoamerica and South America suggests that certain sampled populations (e.g., Mixe) have at least partial ancestry in present-day Indigenous groups from unknown genomic lineages in the Americas, possibly dating as far back as 25,000 years ago. . . .

With multiple genomic analyses showing the ancient Blood/Blackfoot clustering together with present-day Blood/Blackfoot but on a separate lineage from other North and South American groups, we created a demographic model using momi2, which used the site frequency spectra of present-day Blood/Blackfoot, Athabascan (as a representative of Northern Native American lineage), Karitiana (as a representative of Southern Native American lineage), and Han, English, Finnish, and French representing lineages from Eurasia. The best-fitting model shows a split time of the present-day Blood/Blackfoot at 18,104 years ago, followed by a split of Athabascan and Karitiana at 13,031 years ago.

The paper and its abstract are as follows:

Mutually beneficial partnerships between genomics researchers and North American Indigenous Nations are rare yet becoming more common. Here, we present one such partnership that provides insight into the peopling of the Americas and furnishes another line of evidence that can be used to further treaty and aboriginal rights. We show that the genomics of sampled individuals from the Blackfoot Confederacy belong to a previously undescribed ancient lineage that diverged from other genomic lineages in the Americas in Late Pleistocene times. Using multiple complementary forms of knowledge, we provide a scenario for Blackfoot population history that fits with oral tradition and provides a plausible model for the evolutionary process of the peopling of the Americas.

Dorothy First Rider, et al., "Genomic analyses correspond with deep persistence of peoples of Blackfoot Confederacy from glacial times" 10(14) Science Advances (April 3, 2024).

Population Replacement In The Columbian Highlands

In Europe, the first farmers of Europe, derived from Western Anatolian farmers, largely replaced Europe's original hunter-gatherers (who actually show continuity between the periods before and immediately after the Last Glacial Maximum), and in turn, received very substantial genetic admixture from late Copper Age/early Bronze Age Indo-Europeans from more or less where Ukraine is today. This diluted both first farmer ancestry, and the already highly diluted European hunter-gather ancestry that was admixed into those first farmer populations. In some places, like Britain, the population replacement of first farmers by Indo-Europeans was nearly complete.

Something similar apparently happened in East and Southeast Asia.

A new study established that the Americas did not break from this pattern, with some of its early agriculturists replacing pre-existing hunter-gatherer populations in a similarly genocidal pattern. If anything, this replacement was even more complete.

Sometime between 4000 BCE and 0 CE, in the Columbian highlands, probably coinciding with a new archaeological culture whose artifacts appear around 1000 BCE to 800 BCE, a millennium after maize cultivation began around 1800 BCE (but possibly before the full blown ceramic culture emerged), a clade of indigenous South American hunter-gatherers (with ancestry dating back to the initial wave of human settlement of South America) were replaced by a different group of indigenous South Americans.

The 1800 BCE date is from A. Gómez, et al., "A Holocene pollen record of vegetation change and human impact from Pantano de Vargas, an intra-Andean basin of Duitama, Colombia." 145 Rev. Palaeobot. Palynol. 143–157 (2007) (full paper available here), and really only definitively points to deforestation and Amaranth cultivation at that point in the highlands of Columbia.

From Wikipedia.

The population that replaced them, which is genetically linked to the speakers of Chibchan languages and probably originated in Central America, has remained the dominant population of the region in genetic continuity with their ancestors since this population replacement occurred, although later populations admixed with them and brought new languages in some parts of the region. 

There is no evidence that anyone from the pre-agricultural, pre-ceramic culture that was replaced in the Columbian highlands survived, or even significantly admixed with surviving populations.

The new agriculturalist culture did not really come into its own archaeologically until 1000 BCE to 800 BCE, so we can't know for sure if the replacement took place suddenly (although the lack of admixture between the new and old populations suggests that it did) or more gradually, or how long after maize cultivation, a thousand years earlier than this culture's pots appeared, the population replacement happened. 

Conservatively, it happened in some short time period between 1800 BCE and 800 BCE (about 3,000 to 4,000 years after it happened in Europe). Realistically, it probably happened on the later side of that time range when other components of the emerging farmer culture, like pottery and possibly other key domesticated plants and/or animals, joined with improved maize cultivation to give rise to a technologically dominant new culture.

The introduction and discussion sections of a new study released May 28, 2025 in the journal Scientific Advances by Kim-Louise Krettek, et al., explain that:

Genetic studies on ancient and present-day Indigenous populations have substantially contributed to the understanding of the settlement of the Americas. Those studies revealed that the population ancestral to non-Arctic Native Americans derives from a genetic admixture between ancient East Asian and Siberian groups somewhere in North-East Asia before 20,000 years before the present (yr B.P.). Around 16,000 yr B.P., after its arrival in North America, this genetic ancestry split into two lineages known as northern Native American and southern Native American. While northern Native American ancestry is largely confined to ancient and current populations of North America, the southern Native American lineage expanded further south and constitutes the main ancestry component of ancient and present-day Indigenous South Americans. 

Southern Native American ancestry diversified within North America into at least three sublineages, i.e., one related to the Clovis-associated Anzick-1 individual from western Montana (USA), one found in ancient California Channel Islands individuals and the last one representing the main ancestry source of modern-day Central and South Americans.  

Each of these sublineages provided a wave of ancestry into the gene pool of ancient South Americans. Individuals from Chile and Brazil dating back to around 12,000 and 10,000 yr B.P., respectively, were more genetically related to the Anzick-1 genome than individuals from the eastern Southern American coast, Southern Cone and the Andes from 10,000 yr B.P. onward. In addition, the California Channel Islands ancestry was found in the Central Andes by 4200 yr B.P. and became widespread in the region thereafter. However, the exact timing of these population movements into the southern subcontinent remains largely unsolved to date. 

The Isthmo-Colombian area, stretching from the coast of Honduras to the northern Colombian Andes, is critical to understanding the peopling of the Americas. Besides being the land bridge between North and South America, it is at the center of the three major cultural regions of Mesoamerica, Amazonia, and the Andes. At the time of European contact, the region was inhabited by a complex mosaic of human populations, mainly speakers of Chibchan, Chocoan, Carib, and Arawakan languages. 

Among those populations, those who were speakers of Chibchan languages were the most widespread in the region in terms of demography, cultural diversity, and territorial distribution. Chibchan is a language family with multiple, highly distinct branches, many of which are still spoken today in different regions of the Isthmo-Colombian area. The homeland and antiquity of the Proto-Chibchan language and the ancestor of all Chibchan languages remain subjects of debate. High intrafamily variation in terms of lexicon and grammar suggests that the language family is ancient and began diversifying several thousand years ago. The locus of that incipient diversification, however, is still uncertain. Most scholars believe that this protolanguage began to diversify in Lower Central America, where the largest number of these languages is spoken today. However, some evidence suggests that Proto-Chibchan might have originated in South America and then diversified in Central America at a much later date. 

Genetic studies of ancient and present-day Isthmo-Colombian Indigenous populations revealed a distinctive ancestry component primarily associated with speakers of Chibchan languages. However, whereas mitochondrial DNA (mtDNA) studies suggested a migration of Chibchan-related ancestry from Central America into Colombia and Venezuela, genome-wide studies favored an opposite, south-to-north population movement. According to the latter model, speakers of Chibchan languages from Central America are not direct descendants of the first settlers in the region but, instead, derive from a more recent back migration from South to Central America. 

The southernmost region of the Isthmo-Colombian area is the Altiplano Cundiboyacense (hereafter Altiplano). This plateau with an average altitude of 2600 m in the Eastern Cordillera of the Colombian Andes was inhabited by ancient hunter-gatherer groups from the Late Pleistocene. During the Early and Middle Holocene phases of the Preceramic period (~11,500 to 4000 yr B.P.), populations on the Altiplano underwent multiple cultural transformations, most notably increased sedentism and a transition from a hunter-gatherer subsistence to the introduction of horticultural practices and forest management. However, it was not until the early Late Holocene, ~3800 yr B.P., that the first clear evidence of maize cultivation appeared. 

During the subsequent Formative period (~3000 to 1000 yr B.P.), a distinct type of pottery emerged on the Altiplano that is referred to as the Herrera ceramic complex, also known in the literature as the Herrera period (2800 to 1200 yr B.P.). It is still highly debated whether Herrera-associated groups on the Altiplano derived from an in situ development of local hunter-gatherers or were a consequence of population dispersals into the region. 

Around 1200 yr B.P., a cultural phase, known as the Muisca period, began on the Altiplano and lasted until the imposition of the Hispanic Colonial regime in the mid-16th century. Most available evidence is suggestive of population continuity with the preceding Herrera period. The Muisca period is characterized by a relatively continuous process of demographic growth, development of agriculture and trade, and social and political complexification. These factors played a considerable role in shaping the Muisca culture and gave rise to the Chibchan-speaking population that dominated the Altiplano until European colonization. 

While several studies have reported mtDNA data from ancient Colombian individuals, genome-wide data from this region are still entirely lacking to date. In this study, we generated mtDNA and genome-wide data of 21 ancient individuals from two areas of the Altiplano (Bogotá plateau and Los Curos). Our data, spanning a time transect between around 6000 and 500 yr B.P., provide an opportunity to explore several key questions: 

(i) Which southern Native American genetic ancestry do Preceramic individuals from the Altiplano derive from? 

(ii) Were the cultural transformations associated with the Herrera and Muisca periods accompanied by migrations and demographic changes? 

(iii) How is the genetic ancestry observed in speakers of Chibchan languages related to that of ancient individuals from the Altiplano? 

(iv) What are the genetic relationships between the generated ancient genomes and the existing genomic data of present-day Indigenous communities from Colombia and neighboring regions?

In this study, we generated genome-wide data from 21 individuals spanning a time transect of almost 6000 years from the Altiplano, which represents the southern edge of the Isthmo-Colombian area. Our findings contribute to a better understanding of the population history of this area, a key region in the peopling process of South America. We show that the hunter-gatherer population from the Altiplano dated to around 6000 yr B.P. lack the genetic ancestry related to the Clovis-associated Anzick-1 genome and to ancient California Channel Island individuals, suggesting their affiliation to the southern Native American lineage that became the primary source of ancestry of South Americans by 9000 yr B.P. 

However, unlike ancient genomes from the Andes and the Southern Cone that are associated with the same wave of ancestry, the analyzed Preceramic individuals from Colombia do not share distinct affinity with any ancient or modern-day population from Central and South America studied to date. Colombia_Checua_6000BP can thus be modeled as a previously undescribed distinct lineage deriving from the radiation event that gave rise to multiple populations across South America during its initial settlement. 

The cultural transition between the Preceramic and Herrera periods is associated with a seemingly complete replacement of the local genetic profile. This challenges the model where local hunter-gatherers developed in situ as suggested by morphometric studies and an ancient mtDNA time transect. Instead, our study provides evidence for a major genetic turnover on the Altiplano occurring after 6000 yr B.P. but before 2000 yr B.P. Since the mechanisms and precise temporal scale of this replacement event remain uncertain, we cannot directly associate it with the emergence of maize cultivation ~3800 yr B.P. However, our data do support the archaeological hypothesis that the introduction of pottery associated with the Herrera ceramic complex was mediated through population dispersals. 

Our results show that the incoming genetic ancestry on the Altiplano is related to ancient and present-day populations speaking Chibchan languages from Central America. This can be explained most parsimoniously by Chibchan-related migrations from Lower Central America to South America, rather than back-migration to the isthmus. 

A separate study found evidence for a previously unknown south-to-north expansion of Chibchan-related ancestry from Lower Central America into the Mayan territories of Belize by 5600 yr B.P. Therefore, rather than modeling Central American populations associated with Chibchan languages as deriving from a mixture between North and South American ancestries, these results are consistent with an origin of Chibchan-related ancestries in Lower Central America, followed by bidirectional gene flow toward both Meso- and South America. This model of an original “Chibchan homeland” in Central America is supported not only by mtDNA studies on present-day populations who speak Chibchan languages but also from linguistic observations, indicating that the isthmus region exhibits the highest diversity within this language family. 

From an archaeological perspective, the Chibchan-related ancestry is first identified in 2000-year-old individuals associated with Herrera ceramics. In addition, previously sequenced Ceramic-associated individuals from Venezuela dated to 2400 yr B.P. also showed a high affinity to Central American populations speaking Chibchan languages. Despite the similar ancestry pattern and temporal frame, the two populations do not appear to form a simple sister group. This could be in line with linguistic evidence that suggests multiple, distinct Chibchan language expansions into South America, but additional studies will be necessary to further clarify this issue. 

After the arrival of the Chibchan-related ancestry, which completely reshaped the genetic landscape of the region, we find evidence of a long period of genetic continuity in the genetic profile of the local populations for over 1500 years (from at least 2000 to 500 yr B.P.). The stability in genetic ancestry encompasses the end of the Herrera period and the beginning of the Muisca period. This points to a scenario in which populations speaking languages from the Chibchan lineage would have settled the Altiplano before the emergence of traits normally associated with the Muisca culture, and it shows that this cultural transition took place without a substantial migration from regions with a distinct genetic ancestry composition. In addition, such a genetic continuity extends through different cultural phases within the Muisca period and persists until the Spanish colonization. Colonial linguistic documentation established that Muisca people spoke a now extinct Chibchan language. Our findings not only confirm their genetic link with speakers of Chibchan languages from Central America but also suggest that ancestral Chibchan languages, possibly basal to the Magdalenic branch that gave rise to the documented Muisca language, might have already been spoken on the Altiplano during the pre-Muisca Herrera period. 

While the representation of Indigenous populations in our dataset is certainly not exhaustive, the observed spatial pattern in the genetic affinity of post-2000 yr B.P. ancient Colombians with present-day Indigenous populations raises questions regarding the uneven distribution of populations speaking Chibchan languages across the Isthmo-Colombian area at the time of the Hispanic colonization, also referred to as a Chibchan “archipelago”. 

One possible explanation is that this distribution resulted from separate dispersals from Central America to different locations of northern South America rather than a single expansion wave, as suggested by the internal branching pattern of the Chibchan language family. However, it is also possible that the initial spread was more widespread and got later fragmented by post-Chibchan migration and admixture events. The observation that Chibchan-affiliated populations from northern Colombia have a significantly reduced genetic affinity to post-2000–yr B.P. ancient Colombians than to Lower Central Americans supports the role of population admixture in shaping the genetic diversity of northern South America.

Also, while the earlier South American hunter-gatherer clade that went extinct probably dated to the founding wave of the modern humans in South America, they did not have notable Australasian or Melanesian ancestry, disfavoring the existence of a dramatically genetically distinct founding population of the Americas that preceded the main founding wave of modern humans and has Australasian or Melanesian genetic affinities that ancient.

Ancient UP Agriculture

Drone based LIDAR has made a major new find in North America:

A new study has found that a thickly forested sliver of Michigan’s Upper Peninsula is the most complete ancient agricultural location in the eastern United States. The Sixty Islands archaeological site is recognized as the ancestral home of the Menominee Nation. Known to the members of the tribe as Anaem Omot (Dog’s Belly), the area is a destination of pilgrimage, where remains of the settlement date to as far back as 8,000 B.C.

Located along a two-mile stretch of the Menominee River, Sixty Islands is defined by its cold temperatures, poor soil quality and short growing season. Although the land has long been considered unsuitable for farming, an academic paper published on Thursday in the journal Science revealed that the Menominee’s forbears cultivated vast fields of corn and potentially other crops there.

From the New York Times.

I'll update if time permits after reading the full paper.

New World Y1K Demographic Trends

Viewing event 350 years apart as part of the same trend is further in the direction of lumping than I'm comfortable with, but it is good to have a perspective on the pre-Columbian Americas that isn't static, with the implicit assumption that it was always the way it was when Europeans first encountered it.

[A] team led by archaeologist Robert Kelly of the University of Wyoming has studied this period using a previously assembled database of some 100,000 radiocarbon dates from across the United States. (See “Save the Dates.”) They used the dates to track population movements and demographic decline during this turbulent era, which was marked by drought, warfare, and disease. “We knew in a piecemeal fashion that these conditions drove demographic changes in different regions,” says Kelly. “But the radiocarbon data gives us a powerful new tool to understand population decline across the continent.”

After dividing the United States into 18 watersheds, the team analyzed the frequency of radiocarbon dates in each region and demonstrated that a cascading demographic collapse began in the central Rockies around a.d. 800 and later accelerated in multiple regions of central North America after 1150. The team’s analysis shows that the population of watersheds in California, the Pacific Northwest, the Great Lakes, and New England actually grew during the same period. This was likely because groups made their way from regions stricken by drought and warfare toward the coasts. Nonetheless, the radiocarbon data suggests that the overall Native American population declined by at least 30 percent from its peak before 1150.

From Archaeology Magazine.

More On 22,000 Year Old Footprints In New Mexico

According to a new study, ancient footprints and drag marks at White Sands National Park in New Mexico suggest the earliest known North Americans used wooden travois-like "vehicles" to transport goods, and possibly even people, 22,000 years ago.

This account is based upon:

A travois is crafted from one or more wooden poles and is one of the simplest prehistoric vehicles. Although these devices likely played vital roles in the lives of ancient peoples, they have low preservation potential in the archaeological record. Here we report linear features associated with human footprints, some of which are dated to ∼22,000 years old, preserved in fine-grained sediments at White Sands National Park (New Mexico, USA). Using a range of examples, we identify three morphological types of trace in late Pleistocene sediments. Type I features occur as single, or bifurcating, narrow (depth > width) grooves which extend in planform from 2 to 50 m in length and trace either straight, gently curved or more irregular lines. They are associated with human footprints, which are truncated longitudinally by the groove and are not associated with other animal tracks. Type II examples are broader (width > depth) and form shallow runnels that typically have straight planforms and may truncate human footprints to one side. Type III examples consist of two parallel, equidistant grooves between 250 and 350 mm apart. They trace gently curving lines that can extend for 30+ m. Human footprints are associated with these features and may occur between, and to the side of, the parallel grooves. We review a range of possible interpretations including both human and non-human explanations and conclude that the most parsimonious explanation is that they represent drag marks formed by travois consisting of a single pole or crossed poles pulled by humans, presumably during the transport of resources. As such this unique footprint record may represent one of the earliest pieces of evidence for the use of transport technology.

Bennett, M. R., et al., "The ichnology of White Sands (New Mexico): Linear traces and human footprints, evidence of transport technology?" Quaternary Science Advances, 17(100274), 100274 (2025) (open access) doi:10.1016/j.qsa.2025.100274

The dating was confirmed in this 2023 paper:

Editor’s summary 

Traditionally, researchers believed that humans arrived in North America around 16,000 to 13,000 years ago. Recently, however, evidence has accumulated supporting a much earlier date. In 2021, fossilized footprints from White Sands National Park in New Mexico were dated to between 20,000 and 23,000 years ago, providing key evidence for earlier occupation, although this finding was controversial. Pigati et al. returned to the White Sands footprints and obtained new dates from multiple, highly reliable sources (see the Perspective by Philippsen). They, too, resolved dates of 20,000 to 23,000 years ago, reconfirming that humans were present far south of the ice sheets during the Last Glacial Maximum. 

—Sacha Vignieri 

Abstract 

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.

Jeffrey S. Pigati, et al., "Independent age estimates resolve the controversy of ancient human footprints at White Sands" 382 (6666) Science 73-75 (October 5, 2023).

Human Migration To South America

A new, rather mediocre, study that emphasizes genetic diversity in South America tends to track the New World settlement paradigm rather closely. Honestly, for a major new paper in a major scientific journal, it adds surprisingly little to existing knowledge. 

Uncontacted or recently contacted populations in Amazonia and Papuans are the least genetically diverse.  This study, by not mentioning it at all, seems to disfavor the hypothesis of ancient Papuan/Australasian ancestry in Amazonian populations in South America, although this is a key issue in South American population history that really should have been at least discussed in this paper, even if it couldn't reach a definitive conclusion regarding this point with its own data.

The paper also, implicitly suggests (consistent with prior research), that progenitor modern human populations that left foot prints in New Mexico about 23,000 years ago made only an indiscernible impact, if any, on the primary founding population of the Americas starting around 14,000 years ago. A better discussion of how the genetic profiles of Native American in North America differs from those in South America would also have been welcome. It seems to suggest a somewhat older than conventional population history for the founding population of North America, but does so with little meaningful discussion of North American population genetics.

The lack of data from the Atlantic coast of South America and the very thin data from the Amazon, even compared to prior studies of South American genetics, also suggests to me that it is possible that there could be five rather than four main branches of South American settlement. Even if one can't find "pure" indigenous South American ancestry in this region, it should be possible from large databases of modern populations in this region from prior studies, which is home to a large share of all South Americans, to make strong inferences about it from individuals modern populations in the region with indigenous admixture.

There is also too little discussion of the population genetic impact of the Columbian Exchange on either the main different population groups it infers in South America or on the strength of the inferences it is making. We would expect this event in the last 500 years to cause strong fitness based selection, and possibly hard selective sweeps on HLA genetic diversity, an rate unprecedented in the previous 13,500 years, and HLA genetic diversity is one of the important pieces of data that the study examines. But this question isn't elevated or focused upon by the authors.

Editor’s summary

From our origins in Africa, humans have migrated and settled across the world. Perhaps none of these migrations has been the subject of as much debate as the expansion into and throughout the Americas. Gusareva et al. used 1537 whole-genome sequenced samples from 139 populations in South America and Northeast Eurasia to shed light on the population history of Native Americans. Collected as a part of the GenomeAsia 100K consortium, analysis of these data showed that there are four main ancestral lineages that contributed to modern South Americans. These lineages diverged from each other between 10,000 and 14,000 years ago, and this analysis reveals more details of the population history dynamics in these groups. —Corinne Simonti

Abstract

Genome sequencing of 1537 individuals from 139 ethnic groups reveals the genetic characteristics of understudied populations in North Asia and South America. Our analysis demonstrates that West Siberian ancestry, represented by the Kets and Nenets, contributed to the genetic ancestry of most Siberian populations. West Beringians, including the Koryaks, Inuit, and Luoravetlans, exhibit genetic adaptation to Arctic climate, including medically relevant variants. 

In South America, early migrants split into four groups—Amazonians, Andeans, Chaco Amerindians, and Patagonians—~13,900 years ago. Their longest migration led to population decline, whereas settlement in South America’s diverse environments caused instant spatial isolation, reducing genetic and immunogenic diversity. These findings highlight how population history and environmental pressures shaped the genetic architecture of human populations across North Asia and South America.

Abstract

INTRODUCTION

During the late Pleistocene, humans expanded across Eurasia and eventually migrated to the Americas. Those who reached Patagonia, at the southern tip of South America, completed the longest migration out of Africa.

RATIONALE

The extent of basal divergences, admixture, and degrees of isolation among Indigenous North Eurasian and Native South American populations remain debated, with most insights derived from genome-wide genotyping data. This study aims to deepen our understanding of the ancient dynamics that shaped contemporary populations in North Eurasia and the Americas. By using large-scale whole-genome sequencing of 1537 individuals from 139 ethnic groups in these regions, we examined population structures, elucidated prehistoric migrations, and explored the influence of past environmental factors on the diversification of human populations.

RESULTS

Advances in large-scale genomic sequencing have considerably enhanced our understanding of the genetic ancestry of human populations across North Eurasia and South America. Our analysis reveals that all contemporary Siberians, as well as some Northeast Europeans and Central Asians, share ancestry with the West Siberian groups, represented by the Kets and Nenets. Their ancestors were widespread across Siberia 10,000 years ago (ya), but now these groups face population decline by 73.6% and are becoming a minority.

The populations of west Beringia, including the Koryaks, Inuit, and Luoravetlans, are the most genetically distinct from other Siberians. These groups have adapted to Arctic conditions with genetic variations related to lipid metabolism, thermogenesis, sensory perception, and the regulation of reproductive and immune functions. 

We were not able to identify a specific Siberian group as the direct ancestors of Native Americans owing to deep divergence and limited genetic continuity. However, west Beringian populations remain closely related to Native Americans. Koryaks and Inuit show 5 and 28% Native American ancestry, respectively, owing to gene flow between 700 and 5100 ya.

We estimated the split time of Native South Americas into Amazonians, Andeans, Chaco Amerindians, and Patagonians to have occurred 13,900 to 10,000 ya. Migration and settlement across the continent led to population isolations due to geographic boundaries and a reduction in their genetic diversity, particularly affecting immune genes, such as the human leukocyte antigen (HLA) genes. Over the past 10,000 years, all four Native South American lineages have experienced population declines ranging from 38 to 80%. This dramatic decline, combined with the loss of traditional lifestyles, cultural practices, and languages, has pushed some Indigenous communities, such as the Kawésqar, to the brink of extinction.

CONCLUSION

The migration to an uninhabited continent of South America through the narrow Isthmus of Panama resulted in a founder effect among Native South Americans, leading to reduced genetic diversity compared with that of Indigenous populations of North Eurasia. Over 13,900 years, geographic barriers within the continent further isolated Indigenous groups, subsequently reducing genetic diversity. These groups faced a profound challenge with the arrival of European colonists in the 1600s, who introduced new adversities that threatened their long-standing endurance. 

Genetic ancestry and nucleotide diversity. 

Colors represent genetic ancestries estimated by whole-genome sequencing data of contemporary human populations. Countries having no data remained empty. Circle size indicates the average nucleotide diversity of each population.

Elena S. Gusareva, et al., "From North Asia to South America: Tracing the longest human migration through genomic sequencing" 388 (6748) Science (May 15, 2025) DOI: 10.1126/science.adk5081

The introduction in the body text puts the findings in context:

The late Pleistocene saw the expansion of humans into the frigid lands of Eurasia. The earliest known presence of modern humans in northern Eurasia at latitudes greater than 50°N was around 45,000 years ago (ya) in West Siberia, and by 31,600 ya, humans had migrated far east toward Beringia, north of the Arctic Circle at 71° N. The earliest human remains identified in this region are two Yana Rhinoceros Horn Site individuals that, despite their extreme Northeast Siberian geographical location, show substantial genetic relatedness to early West Eurasian hunter-gatherers. 

The Upper Palaeolithic people who initially populated Northeast Siberia were then replaced by arrivals from East Asia. The Kolyma1 remains, excavated near the Chukotka region and dated as being from 9800 ya, demonstrate greater affinity to East Asians and present-day west Beringian populations, such as Koryaks and Luoravetlans (also known as Chukchi), as well as to Native Americans. The linguistic and cultural diversity of present-day Indigenous Siberian populations is mirrored by the complex patterns of admixture, as shown by genome-wide genotype data analysis. This genetic structure in Siberians, comprising several ancestral components, is estimated to have emerged within the past 10,000 to ~3400 years. The Western Eurasian ancestry component presented in a majority of Indigenous Siberian populations is not the result of postcolonial Russian admixture but one of the ancient components dating back to 12,500 to 25,000 ya in different Siberian populations. Among the present-day populations of Northeast Eurasia, the Koryaks from the Kamchatka Peninsula and the Inuit from Chukotka show the closest genetic relatedness to Native North Americans. 

The migration of humans to the Americas occurred when the Bering Land Bridge was still open, with the earliest human remains in North America found in the Clovis burial site in western Montana dating back to around 12,700 ya. However, recent evidence suggests human presence in North America from at least 23,000 ya. By the time the Ice-Free Corridor opened up and became suitable for travel around 13,300 ya, humans were already widely dispersed in North America, likely owing to Pacific coastal migration routes. The divergence between northern and southern Native American populations is estimated to have occurred between 17,500 and 14,600 ya south of the North American ice sheets, according to modern and ancient genomic analyses. The rapid dispersal of humans in South America is suggested by archaeological records, which date the earliest human presence in North Patagonia, the southernmost tip of the Americas, to 14,500 ya. However, the number of basal divergences, founding populations, admixture, and the degrees of isolation among Native South American populations remain a subject of debate, with most of the current understanding coming from analyses of genome-wide genotyping or ancient DNA data. Additionally, fine-scale population genetic studies based on high-coverage whole-genome sequencing datasets for contemporary populations of North Eurasia and South America have not been performed to date.

The body text's discussion of population decline in South America (which has been continuous and not just entirely due to the Columbian exchange) is notable since rare haplotypes and ancestrally informative genes are strongly prone to being purged in periods of declining population (while happens only rarely in expanding populations). Consistent with this these populations have low genetic diversity.

The population split time estimates also suggest that the divergence of the four Native South American lineages occurred over a short period, from 13,900 to 10,000 ya. All four lineages show a continuous population decline. However, the Andean highlanders managed to maintain their population size during the rise of maize horticulture around 5200 to 3700 ya. It has declined by 45.1% since then (Ne from 1771 to 972), whereas Chaco Amerindians have declined by 46.89% (Ne from 1448 to 769) since 10,000 ya. Amazonians and especially Patagonians have seen a dramatic decrease in population size over the past 10,000 years, with declines of 66.59% (Ne from 1368 to 457) and 79.68% (Ne from 1171 to 238), respectively.

To assess the impact of population decline on genetic diversity, we estimated genome-wide runs of homozygosity (ROHs) segments. In Native South Americans, the average number and length of ROHs segments estimated across all populations were 10.5 and 1.3 times higher than those in Africans (Yoruba) and 3.75 and 1.2 times higher than those in Northeast Europeans, respectively. The highest abundance of extended ROHs was observed in Amazonians, Patagonian Kawésqar, and Chaco Amerindians and was similar to that seen in isolated island populations, such as the Andamanese and Baining. This high homozygosity is likely the result of the founder effect due to long-distance migration and/or population isolation. The strong correlation between the average total number of ROHs and the average nucleotide diversity (Pearson correlation coefficient r = –0.78) supports the idea that the extended homozygosity is a result of population history.

The body text of the discussion section notes that:

Our analysis of whole-genome datasets also allowed us to infer the split time between North Eurasians and Native Americans, which occurred between 26,800 and 19,300 ya. This finding is consistent with estimates based on the recently published paleontological discovery of human footprints in North America (south-central New Mexico) dating back to 23,000 and 21,000 ya, as well as with other genetic studies, despite differences in the cohorts that were investigated. 

A previous study of ancient genomes suggests limited genetic continuity in Beringia, as the most recent Arctic colonization occurred 6000 ya. Therefore, it is likely that the first ancestors of the Native Americans in this region were replaced by the most recent wave of migration. We could not identify a specific Siberian group as direct Native American ancestors among the contemporary Indigenous populations in our dataset. However, we show that west Beringian populations, such as Inuit, Luoravetlans, and Koryaks, are genetically the closest to Native Americans. Moreover, we revealed the gene flow from Native Americans back to Inuit and Koryaks in Chukotka and the Kamchatka Peninsula between 700 to 5100 ya. Our analyses also demonstrated the shared ancestry between the west Beringian populations and contemporary Native North Americans, particularly the Chipewyan from Canada. This genetic relatedness is consistent with the PCA results. These findings are in line with previous reports that describe multiple waves of Northeast Asian gene flow into North Americans, including Neo-Inuit lineages. 

By using our genome sequencing data from diverse Native South Americans, we have discovered that the simultaneous split of the four Native South American ancestral lineages occurred between 13,900 and 10,000 ya from a common ancestral population in Mesoamerica. This rapid radial dispersal and the establishment of sedentary settlements across South America are supported by previous genetic studies and the archaeological findings of early technologies (such as stone tools) that indicate regional cultural diversification in South America from at least 13,000 ya. This divergence occurred shortly after the split of the ancestral Native American lineages into northern and southern branches, which happened between 17,500 and 14,600 ya south of the North American ice sheets. By the time the Ice-Free Corridor was fully opened 14,300 to 13,300 ya during the abrupt warming, humans were already widely dispersed in North America. 

Our study shows that the human migration across South America resulted in population splits with a loss of genetic diversity due to founder effects. Geographical and environmental boundaries caused population isolation and further enhanced the genetic homogenization, similar to islander populations. The demographic history has greatly influenced the Patagonian Kawésqar, whose ancestors migrated the farthest distance out of Africa. They have the smallest effective population size and one of the smallest genetic distances between community members. It has been reported that contemporary Native Patagonians (including the Kawésqar) show the highest genetic affinity to ancient Patagonian maritime individuals that lived 1000 ya, indicating genetic continuity in the region. Our study cannot provide evidence for the reported back migration from the Southern Cone along South America's Atlantic coast owing to a lack of data on east coastal Native South American populations. 

Our study also suggests that close genetic relatedness in Indigenous populations, along with reduced heterozygosity in HLA genes, may impact antigen recognition ability to new unexposed pathogens. In combination with socioeconomic factors and limited access to medical care, this could pose a potential health risk. High–pathogen load regions, such as Southeast Asia, tend to have a higher diversity of promiscuous HLA-DRB1 alleles, which allows them to respond to a wider range of extracellular pathogens. However, emerging evidence that divergent allele advantage (a mechanism where the HLA genotypes present a broader set of epitopes) and increase in HLA alleles promiscuity level may counterplay the effect of loss of heterozygosity in HLA genes. Our work highlights a noteworthy implication for future research in population-based disease cohorts: Epitope-binding repertoire studies are essential for identifying the dynamic effects of limited HLA diversity on disease susceptibility. 

Access to the vastness of the South American continent was constrained by the relatively small landmass of the Isthmus of Panama. Consequently, migrating groups could only inhabit the continent from a singular direction, limiting the genetic diversity of human individuals. This ultimately led to the emergence of the four ancestries described in our analysis. Although Indigenous groups managed to maintain their populations for over 13 millennia with minimal interaction with other groups, their endurance faced a critical challenge with the arrival of the initial colonists in the 1600s.

Cannibalism Was A Thing In Post-Glacial Hunter-Gather Poland

Just two thousand years after the Last Glacial Maximum in Europe, near the fringe of the retreating glaciers, the hunter-gathers repopulated Europe from refugia in the Caucuses, on the Italian Peninsula, and from Iberia. These people sometimes practiced cannibalism. We don't fully understand why, but their life did involve living on the brink of starvation for extended period of time. 

It could be that the taboo against cannibalism was first broken in some situation where it was dictated by dire necessity, and that once this taboo was broken, the practice morphed into something with religious significance or a way to treat troublesome rivals or enemies, that perhaps helped them deal with the guilt that arose from breaking the taboo the first time. 

Then again, human sacrifice and cannibalism were practiced in the Americas after the Neolithic revolution occurred independently there in circumstances where the threat of starvation was probably a more distant memory.

The manipulation of human corpses started to become commonplace during the Upper Paleolithic. This well-documented behavior among Magdalenian peoples consists of perimortem manipulation and the removal of soft tissues and has been understood as forming part of the cultural repertoire of mortuary actions. 

The study of these practices has given rise to several interpretations with the consumption of human flesh (cannibalism) occupying a central position. The human assemblage of Maszycka Cave (18,000 cal. BP) is part of this ongoing debate. Although initial research in the 1990s suggested cannibalism, more recent studies challenge this interpretation arguing that the low incidence of human activity rule out the likelihood of processing for the purpose of consumption and proposing skull selection as a funerary practice. 

This study reviews the assemblage and presents previously unpublished postcranial skeletal specimens along with evidence of whole-body manipulation for consumption. This behavior is also observed in other chronologically and culturally similar assemblages throughout continental Europe, suggesting that cannibalism was integral practice within the cultural systems of these Magdalenian groups.

Marginedas, F., Saladié, P., Połtowicz-Bobak, M. et al. New insights of cultural cannibalism amongst Magdalenian groups at Maszycka Cave, Poland. 15 Sci Rep 2351 (2025). https://doi.org/10.1038/s41598-025-86093-w

Human Sacrifice In Northern Peru Ca. 500 CE

A new study analyzed the remains of six people at an elite burial in northern coastal Peru in the Moche culture. One boy and one girl were human sacrifices. They were strangled to death which was the norm for human sacrifices in this region. Unexpectedly, the sacrificed children were themselves part of this royal family. The boy was sacrificed with his father. The girl who was sacrificed was the niece of the woman whom she was sacrificed with, who was the highest ranking figure, probably a queen. The graves were the subject of a memorial fire for at least 166 years.

Ancient DNA From Siberia As A Source For Modern Populations

Different strains of Siberian ancestry spread east to the New World and west to Scandinavia.

Human populations across a vast area in northern Eurasia, from Fennoscandia to Chukotka, share a distinct genetic component often referred to as the Siberian ancestry. Most enriched in present-day Samoyedic-speaking populations such as Nganasans, its origins and history still remain elusive despite the growing list of ancient and present-day genomes from Siberia. 

Here, we reanalyze published ancient and present-day Siberian genomes focusing on the Baikal and Yakutia, resolving key questions regarding their genetic history. First, we show a long-term presence of a unique genetic profile in southern Siberia, up to 6,000 yr ago, which distinctly shares a deep ancestral connection with Native Americans. Second, we provide plausible historical models tracing genetic changes in West Baikal and Yakutia in fine resolution. Third, the Middle Neolithic individual from Yakutia, belonging to the Belkachi culture, serves as the best source so far available for the spread of the Siberian ancestry into Fennoscandia and Greenland. These findings shed light on the genetic legacy of the Siberian ancestry and provide insights into the complex interplay between different populations in northern Eurasia throughout history.

Haechan Gill, Juhyeon Lee, Choongwon Jeon, "Reconstructing the Genetic Relationship between Ancient and Present-Day Siberian Populations" 16(4) Genome Biology and Evolution evae063 (March 25, 2024) https://doi.org/10.1093/gbe/evae063

Clovis People Used Bones Of Small Predators For Needles

The Clovis people (who are not the first indigenous American culture, although they are derived from the Founding population of the Americas whose main wave of expansion came about fifteen hundred years earlier) are known for the spears that they used to hunt big game in North America before the Younger Dryas event wiped out their culture. But to survive in North America, they also needed needles to make clothing so they could function in this relatively cool region.

Tiny artifacts unearthed at a Wyoming site where a mammoth was butchered 13,000 years ago are revealing intriguing details about how the earliest Americans survived the last ice age.

Archaeologists found 32 needle fragments made from animal bone buried almost 15 feet (nearly 5 meters) underground at the La Prele site in Converse County. They are not the earliest eyed needles in the archaeological record, but for the first time scientists have been able to identify what the needles were made of by analyzing protein information contained in the bone collagen. The results were not what they expected.

“We had assumed they would be made out of bison or mammoth bone, which comprise most of the animal bones found at La Prele and other sites of its age in the High Plains and Rocky Mountains of North America,” said Wyoming state archaeologist Spencer Pelton, lead author of a new study on the needles published November 27 in the scientific journal PLOS ONE.

Instead, the needles were created from the bones of red foxes, bobcats, mountain lions, lynx, the now-extinct American cheetah, and hares or rabbits, the study found.

“It was extremely surprising that these needles were made out of small carnivores,” Pelton said.

From CNN. 

More Nazca Lines Found

So says the New York Times, and don't bring aliens into it. It took a century to find the previous 430 of them. There could be as many as 500 more yet to be rediscovered.

Hundreds More Nazca Lines Emerge in Peru’s Desert

With drones and A.I., researchers managed to double the number of mysterious geoglyphs in a matter of months.

Some 303 previously uncharted geoglyphs made by the Nazca, a pre-Inca civilization in present-day Peru dating from 200 B.C. to 700 A.D., were identified with the help of machine learning. . . . 

The Nazca people carved the designs into the earth by scraping back the pebbled, rust-colored surface to expose the yellow-gray subsoil. Little is known about the shadowy culture, which left no written record. Aside from the etchings, pretty much all that exists of the civilization are pieces of pottery and an ingenious, still functioning irrigation network.

The ancient geoglyphs have attracted theories that range from the religious (they were homages to powerful mountain and fertility gods) to the environmental (they were astronomical guides to predict infrequent rains in the nearby Andes) to the fantastical (they were landing strips and parking lots for alien spacecraft).

Dr. Sakai said that geoglyphs were drawn near pilgrimage routes to temples, which implies that they functioned as sacred spaces for community rituals, and could be considered planned, public architecture. The newly discovered geoglyphs are mainly located along a network of trails that wound through the pampa. They were most likely made by individuals and small groups to share information about rites and animal husbandry.

Pre-Colombian New World Admixture In Ancient Easter Island Genomes

Polynesian people reached Easter Island around 1250 CE and were the first humans there. Europeans first reached the island in 1722 CE, at which time there were 1,500 to 3,000 people living there. European diseases, Europeans killing them, and Portuguese slave traders brought the Polynesian population down to a low point of 110 people some time after the 1860s. This paper's introduction suggested that as many as 15,000 people were living on the island on its pre-European peak, but later studies and this paper suggest that this peak population was greatly overestimated. The best fit to the genetic data shows a steady but slow population increase on the island after it was settled until European first contact, and the ecological collapse theory is rejected.

About 10% of Easter Island ancestry comes from pre-Columbian admixture with the indigenous peoples of the Americas as a result of admixture events in the time period from 1250-1430 CE, with a best fit timing in the late 1300s. This date also strongly favors admixture with indigenous Americans after, and not before the ancestors for the sampled individuals arrived on Easter Island. In particular, "the Native American component in Ancient Rapanui to be most closely related to Pacific Coast South Americans and not North Americans or populations east of the Andes further substantiates trans-Pacific contacts between Polynesians and Native Americans."

This further corroborates prior evidence of pre-Columbian contact between Polynesians and the pre-Columbian peoples of the Americas, and is also consistent the with expected time frame of these contacts from prior data.

we reconstructed the genomic history of the Rapanui on the basis of 15 ancient Rapanui individuals that we radiocarbon dated (1670–1950 CE) and whole-genome sequenced (0.4–25.6×). We find that these individuals are Polynesian in origin and most closely related to present-day Rapanui, a finding that will contribute to repatriation efforts. Through effective population size reconstructions and extensive population genetics simulations, we reject a scenario involving a severe population bottleneck during the 1600s, as proposed by the ecocide theory. Furthermore, the ancient and present-day Rapanui carry similar proportions of Native American admixture (about 10%). Using a Bayesian approach integrating genetic and radiocarbon dates, we estimate that this admixture event occurred about 1250–1430 CE.

From here. The body text of the article provides some background:

several pieces of evidence suggest that Rapa Nui did not constitute the easternmost point of long sea voyages and that Polynesian peoples eventually reached the Americas before Columbus. 

Genetic studies on present-day individuals have supported such contact. Present-day Rapanui were found to harbour Native American and European admixture in their genomes. Notably, in that work, Native American admixture (dated 1280–1495 CE) was estimated to pre-date European admixture (dated 1850–1895 CE). 

More recently, Native American admixture was detected not only in present-day individuals from Rapa Nui, but also from Rapa Iti, Tahiti, Palliser, Nuku Hiva (North Marquesas), Fatu Hiva (South Marquesas) and Mangareva. In that study, the Native American gene flow in the different islanders was dated between 1150 (South Marquesas) and 1380 CE (Rapa Nui), in line with the date estimated in ref. 5. 

However, the only two ancient DNA studies of ancient Rapanui so far did not find evidence for Native American admixture. The first study focused on mitochondrial DNA from 12 individuals, whereas the second analysed low-depth (0.0004–0.0041×) whole-genome data from 5 individuals dating before and after European contact. In the latter, downstream population genetic analyses confirmed that the five ancient individuals were Polynesian. However, even though the analysed human remains were post-dating the inferred Native American admixture time, no Native American ancestry was reported in these ancient genomes, casting doubt on the findings based on data from present-day populations.

The admixture and Native American contract dates cited above are also just in the right time frame to explain the geographic distribution and lack of fixation of "Paleo-Asian" ancestry in modern South American populations, although that scarce Paleo-Asian component is very small and is seemingly not a very close match to Polynesian ancestry. 

The geographic spread and lack of fixation of the Paleo-Asian component in South America is inconsistent and irreconcilable with a time depth greater than that of the primary founding population of the Americas for that genetic ancestry component.