Monday, May 22, 2023

Earliest evidence of wine consumption in the Americas found in Caribbean

 

  • Earliest evidence of wine drinking in the Americas found in Caribbean pottery vessels
  • No evidence of fish in ceramics suggests tendency for indigenous people to cook proteins on barbeques
  • Research is first study to use molecular analysis methods on 15th century ceramics from Puerto Rico region

Scientists have found what they believe to be the earliest known evidence of wine drinking in the Americas, inside ceramic artefacts recovered from a small Caribbean island. Forty ceramic sherds were examined in the first study to have used molecular analysis techniques – Gas Chromatography and Mass Spectrometry - to investigate 15th century pottery from the Puerto Rico region.

The research focused on artefacts from the island of Isla de Mona, situated between the Dominican Republic and Puerto Rico. The findings, published in Archaeological and Anthropological Sciences , address questions around dietary changes and cultural exchanges in the Greater Antilles prior to and after European arrival.

Olive jar reveals earliest evidence of wine in the area

In a study was led by the Dr Lisa Briggs , Visiting Researcher at the British Museum and 75th Anniversary Research Fellow at Cranfield University, alongside the University of Leicester.

The analysis included sherds from a Spanish olive jar that could be dated between 1490-1520 AD. The rounded style of the jar shows it to be this early and aligns it to the timing of when Columbus first noted the existence of the island in his diary in 1494.

The olive jar, used then as a general container for all sorts of food and liquid goods, transporting them on Spanish ships, had evidence of wine residues inside.

“Whether consumed by Europeans or members of the indigenous population, this is direct evidence for the importation and drinking of European wine to a tiny island in the Caribbean shortly after the arrival of Spanish colonialists,” say the researchers.

Fusion food experience over 500 years ago

As first generations of Spanish colonists brought European traditions of wine consumption to the area, despite their conquest over indigenous people the local traditions for cooking on barbeques continued.

The researchers believe that barbeque cooking was commonplace among the Taino community, indigenous to this area in the Caribbean, and adopted by early colonists. With no large mammals on the Caribbean islands in this area, it’s likely that the indigenous population would have barbequed a large rodent-like animal called a hutier, as well as iguanas.

Indigenous people in this area of the Caribbean cooked fish and meat with charcoal over a raised grill, and the origin of the word ‘barbeque’ is traced to ‘Barbacoa’ – a word used by the Taino people. The researchers suggest that in some ways, two culinary traditions came together - creating a fusion food and drink experience hundreds of years ago.

Dr Briggs continued: “Two culinary worlds collided in the Caribbean over 500 years ago, driven by the early Spanish colonial impositions. We really didn’t know much about the culinary heritage of this area and the influence of early colonialists on food traditions, so uncovering the discoveries have been really exciting.

“The strong culinary traditions of the Taino people in creating the barbeque held firm despite Spanish colonialism, and influenced food right round the world. This continues today, as we are all familiar with a barbeque. I’m really pleased that this research shines a light on the cultural heritage of this community.”

Indigenous culinary traditions persisted despite colonisers

On excavating the area last year, scientists from the British Museum found many fish and meat bones around the site – but crucially none were found inside cooking pots.

In the Caribbean ceramics analysed, there was no evidence they were used for dairy or meat products. Whilst dairy products were long a staple of European cooking, this does not appear to be the case on Isla de Mona – giving further evidence that indigenous culinary traditions persisted in the face of colonialism and imported ceramic vessels.

“This offers an interesting insight into culinary exchange on the island,” the researchers say. “...it appears traditional foodways were maintained even after an influx of European colonists arrived on the island with their glazed ceramics and olive jars. The lack of evidence for dairy products in our samples further suggests that European colonialists quickly came to adopt and rely on indigenous culinary traditions.”

This indicates that the indigenous people continued to cook proteins on charcoal over a raised grill, and vegetable dishes in the ceramic pots. This culinary tradition is far apart from the contemporary European preference for stews and casseroles – with cooking pots from that area often including meat remnants.

The research paper Molecular evidence for new foodways in the early colonial Caribbean: organic residue analysis at Isla de Mona, Puerto Rico involved a team of researchers from Cranfield University, Leicester University, the University of East Anglia, the University of York and the British Museum.

Sunday, May 21, 2023

Oldest architectural plans detail mysterious desert mega structures


Peer-Reviewed Publication

UNIVERSITY OF FREIBURG

Image 1 

IMAGE: THE DIMENSIONS OF DESERT DRAGONS ONLY BECOME APPARENT FROM THE AIR: AT JEBEL AZ-ZILLIYAT IN SAUDI ARABIA, THE TRUE-TO-SCALE ENGRAVING DEPICTS NEARBY DESERT DRAGONS. view more 

CREDIT: OLIVER BARGE, CNRS

Although human constructions have modified natural spaces for millennia, few plans or maps predate the period of the literate civilizations of Mesopotamia and Ancient Egypt. Researchers from the French research organisation "Centre national de la recherche scientifique" (CNRS), together with Prof. Dr. Frank Preusser from the University of Freiburg, have now been able to identify engravings in Jordan and Saudi Arabia as the oldest known true-to-scale construction plans in human history. The 8,000 to 9,000-year-old engravings depict so-called desert dragons – kilometre long prehistoric megastructures used to trap animals. "Conclusions can be drawn from the findings about the people of the time. The ability to transfer a large space to a small, two-dimensional plan represents a milestone in intelligent behaviour," explains Preusser. The results, which were published in mid-May in the scientific journal PLOS ONE, should help to understand how desert dragons were conceived and built.

Scale plans of desert dragons discovered in Jordan and Saudi Arabia

Both finds are representations of nearby desert dragons engraved with stone tools. First sighted from aircrafts in the 1920s, desert dragons, up to five kilometres long, consist of stone walls that converge in a complex bounded by pits. As archaeologists have been able to determine in recent years, they were used for large-scale trapping of wild animals. In Jordan, there are eight desert dragons in the area of Jibal al-Khasabiyeh. There, the researchers found a depiction engraved in stone that measures 80 by 32 cm, its age is about 9,000 years. At Jebel az-Zilliyat in Saudi Arabia, two visible pairs of dragons are found three and a half kilometres apart. Here, too, a scaled engraving dating back about 8,000 years was discovered with a total length of 382 cm and a width of 235 cm.

Plans of large structures have so far only been attested by rough representations, in stark contrast to the precision of the engravings of al-Khashabiyeh and az-Zilliyat. The question of their exact use and how they were implemented, especially due to the difficulty of grasping the entire complex from the ground, remains for the time being the secret of the people by whom they were created.

 

Overview of facts:

  • Crassard R., Abu-Azizeh W., Barge O., Brochier J.É., Preusser F., Seba H., Kiouche A.E., Régagnon E., Sánchez Priego J.A., Almalki T., Tarawneh M., 2023. The oldest plans to scale of humanmade mega-structures. PLOS ONE 18(5): e0277927. https://doi.org/10.1371/journal.pone.0277927
  • Frank Preusser is Professor for Sedimentology at the Institute for Earth and Environmental Sciences, Faculty of Environment and Natural Resources, at the University of Freiburg. His research emphasis is on the response of terrestrial sedimentary systems to climate change and human impact during the Quaternary. In particular, he is investigating the erosion and depositional history of the Alps and environmental developments on the Arabian Peninsula. A special interest is on geochronology, specifically luminescence dating.
  • The South-Eastern Badia Archaeological Project (SEBAP; research at Jibal al-Khashabiyeh) is funded by grants from the French Ministry of Foreign Affairs, Al-Hussein Bin Talal University (project No. 164/2016) and the CNRS National Institute for Humanities and Social Sciences. The GLOBALKITES project (research at Jebel az-Zilliyat) was funded by a French National Research Agency grant ANR-12-JSH3-0004-01 (RC). The Dumat al-Jandal archaeological project (research at Jebel az-Zilliyat) was funded by grants from the Saudi Heritage Commission, the French and Italian Ministries of Foreign Affairs, CNRS UMR-8167 Orient & Méditerranée, the University L’Orientale of Naples (Guillaume Charloux and Romolo Loreto).

Friday, May 19, 2023

Human ancestry has been shaped by mixing and matching alleles


Peer-Reviewed Publication

SMBE JOURNALS (MOLECULAR BIOLOGY AND EVOLUTION AND GENOME BIOLOGY AND EVOLUTION)

An artistic representation of African population genetics. 

IMAGE: THE EXTENSIVE ADMIXTURE FOUND IN AFRICAN GENOMES IS SYMBOLIZED BY A MARBLED PAINT EFFECT. view more 

CREDIT: JOSEPH LACHANCE ET AL.

The course of human history has been marked by complex patterns of migration, isolation, and admixture, the latter a term that refers to gene flow between individuals from different populations. Admixture results in a blending of genetic lineages, leading to increased genetic diversity within populations. In addition to admixture among modern human populations, ancient humans reproduced with other hominin groups, such as Neanderthals and Denisovans. This resulted in fragments of DNA from these ancient lineages being passed down to modern humans in a process known as introgression. Two recent studies published in Genome Biology and Evolution examine patterns of admixture in two different regions of the world—Africa and the Americas—revealing how this process has shaped the genomes of modern humans.

Africa is the birthplace of humanity, where our species originated and diversified. Because of this, Africa contains the highest levels of genetic diversity and population structure among humans, with non-African populations largely representing a subset of the genetic variation present on the African continent. Genomes of Africans contain mixtures of multiple ancestries, each of which has experienced different evolutionary histories. In the article “Evolutionary Genetics and Admixture in African Populations,” researchers from two institutes – Georgia Institute of Technology and Mediclinic Precise Southern Africa – reviewed how multiple demographic events have shaped African genomes over time (Pfennig, et al. 2023). According to Joseph Lachance, one of the review’s authors, “What stands out is the sheer complexity of human demographic history, especially in Africa. There are many examples of population divergence followed by secondary contact, the legacy of which is written in our genomes.”

For example, ancient introgression from archaic “ghost” populations of hominins that are no longer extant contributed approximately 4–6% of the ancestry of present-day Khoe-San, Mbuti, and western African populations. More recent demographic events that have occurred over the last 10,000 years have similarly resulted in admixture among modern humans, including gene flow among different click-speaking Khoe-San populations, the spread of pastoralism from eastern to southern Africa, and migrations of Bantu speakers across the continent.

Importantly, biomedical studies often fail to capture this diversity, resulting in implications for the health and disease of those with African ancestry. A better understanding of genetic architecture can help predict disease risk in a population or even inform clinical decision-making for individual patients. Such information is critical for equitable biomedical research, leading the study’s authors to call for more ethically conducted studies of genetic variation in Africa. “A critical point right now is the relative lack of African genetic data,” says Lachance. “Most genomic studies have focused on Eurasian populations, and this limitation can exacerbate existing health inequities.”

One avenue for better understanding the genetic architecture of African genomes is the study of ancient DNA: “Going forward, analysis of ancient DNA is expected to become much more common. Future studies are also likely to focus on fine-scale population structure in Africa. However, logistical and financial obstacles persist. There is a clear need for funding mechanisms that build research capacity in Africa.”

A second article recently published in GBE, titled “The impact of modern admixture on archaic human ancestry in human populations,” focuses on admixture in the Americas (Witt, et al. 2023), which were colonized by modern humans relatively recently. The first people to enter the continent were Indigenous Americans who migrated from Siberia. Subsequent migration of Europeans and Africans due to European colonization and the Transatlantic slave trade resulted in admixed populations that combine ancestries from different continents.

In the study, researchers from Brown University, the Universidad Nacional Autónoma de México, and the University of California-Merced analyzed how the resulting gene flow between modern humans redistributed archaic ancestry in admixed genomes. They used data from the 1000 Genomes Project that were acquired from several admixed populations, including Colombians from Medellin, individuals with Mexican Ancestry from Los Angeles, Peruvians from Lima, and Puerto Ricans from Puerto Rico. These genomes were compared to the high-coverage genomes of Neanderthals and Denisovans, ancient hominins that diverged from modern humans about 500,000 years ago and mated with humans in Eurasia before going extinct about 40,000 years ago.

According to one of the study’s authors, Kelsey Witt from Brown University, these admixed populations are relatively understudied compared to more homogeneous populations. “It is common in studies like this for admixed populations to be excluded because the multiple ancestry sources can make those questions harder to answer. For this work, we wanted to focus on admixed populations to determine what we could learn from them, and whether admixed populations could provide information about all of the ancestry sources that contributed to them.”

The study found that the amount of introgression from Neanderthals and Denisovans was proportional to the amount of Indigenous American or European ancestry in each population. Although European and Indigenous American tracts in these admixed genomes have approximately equal proportions of Neanderthal variants, Denisovan variants are found primarily in Indigenous American tracts. This reflects the shared ancestry between Indigenous Americans and Asian populations, which also have higher levels of Denisovan introgression.

Moreover, by searching for archaic alleles present at high frequency in admixed American populations but low frequency in East Asian populations, the study’s authors identified several genes as candidates for adaptive introgression. These genes were related to multiple pathways including immunity, metabolism, and brain development. Such findings have potential implications for the health of individuals in these admixed populations. “We’ve seen many examples of genetic mismatch in the literature,” says Witt, “where some variants were adaptive at some point in the past, but in the present environment, they have a negative impact on health. In addition, in admixed populations, genetic variants that are unique to separate populations may now interact in unexpected (sometimes negative) ways when they are present in the same individual. Our work suggests that some archaic variants are specific to some ancestry sources and not others."

Like Lachance, Witt knows that additional research is needed to continue to untangle the effects of admixture on modern humans. “In a lot of ways, admixed populations in the Americas are straightforward to study because we have a good idea of the timing and number of gene flow events,” notes Witt. “I’d like to apply this work to other admixed populations, where we may not know when admixture occurred or which populations contributed to it, or in cases where the contributing populations are more closely related. I think that the answers in those cases may not be as clear-cut, but they may contribute to a better understanding of those recent admixture events.”

These studies show admixture has played a significant role in shaping human evolution, both in Africa and in the Americas. Admixture not only reshuffles the genetic variation within and between populations, but also introduces new sources of variation that may have adaptive potential. By comparing the genomes of admixed populations with those of their ancestral groups and with those of archaic humans, these studies reveal how the mixing and matching of alleles has shaped the evolution of our species.

Humanity’s earliest recorded kiss occurred in Mesopotamia 4,500 years ago


Written sources document that kissing was practiced by the peoples of the ancient Middle East 4,500 years ago, conclude researchers from the University of Copenhagen and University of Oxford in a new article published in the journal Science.

Peer-Reviewed Publication

UNIVERSITY OF COPENHAGEN - FACULTY OF HUMANITIES

Baked clay couch with erotic scene 

IMAGE: BABYLONIAN CLAY MODEL SHOWING A NUDE COUPLE ON A COUCH ENGAGED IN SEX AND KISSING. DATE: 1800 BC. view more 

CREDIT: © THE TRUSTEES OF THE BRITISH MUSEUM

Recent research has hypothesised that the earliest evidence of human lip kissing originated in a very specific geographical location in South Asia 3,500 years ago, from where it may have spread to other regions, simultaneously accelerating the spread of the herpes simplex virus 1.

But according to Dr Troels Pank Arbøll and Dr Sophie Lund Rasmussen, who in a new article in the journal Science draw on a range of written sources from the earliest Mesopotamian societies, kissing was already a well-established practice 4,500 years ago in the Middle East. And probably much earlier, moving the earliest documentation for kissing back 1,000 years compared to what was previously acknowledged in the scientific community.

“In ancient Mesopotamia, which is the name for the early human cultures that existed between the Euphrates and Tigris rivers in present-day Iraq and Syria, people wrote in cuneiform script on clay tablets. Many thousands of these clay tablets have survived to this day, and they contain clear examples that kissing was considered a part of romantic intimacy in ancient times, just as kissing could be part of friendships and family members’ relations,” says Dr Troels Pank Arbøll, an expert on the history of medicine in Mesopotamia.

He continues:

“Therefore, kissing should not be regarded as a custom that originated exclusively in any single region and spread from there but rather appears to have been practiced in multiple ancient cultures over several millennia.”

Dr Sophie Lund Rasmussen adds:

“In fact, research into bonobos and chimpanzees, the closest living relatives to humans, has shown that both species engage in kissing, which may suggest that the practice of kissing is a fundamental behaviour in humans, explaining why it can be found across cultures.”

Kissing as potential transmitter of disease

In addition to its importance for social and sexual behaviour, the practice of kissing may have played an unintentional role in the transmission of microorganisms, potentially causing viruses to spread among humans.

However, the suggestion that the kiss may be regarded as a sudden biological trigger behind the spread of particular pathogens is more doubtful. The spread of the herpes simplex virus 1, which researchers have suggested could have been accelerated by the introduction of the kiss, is a case in point:

“There is a substantial corpus of medical texts from Mesopotamia, some of which mention a disease with symptoms reminiscent of the herpes simplex virus 1,” Dr Arbøll remarks.

He adds that the ancient medical texts were influenced by a variety of cultural and religious concepts, and it therefore must be emphasized that they cannot be read at face value.

“It is nevertheless interesting to note some similarities between the disease known as buʾshanu in ancient medical texts from Mesopotamia and the symptoms caused by herpes simplex infections. The bu’shanu disease was located primarily in or around the mouth and throat, and symptoms included vesicles in or around the mouth, which is one of the dominant signs of herpes infection.”

“If the practice of kissing was widespread and well-established in a range of ancient societies, the effects of kissing in terms of pathogen transmission must likely have been more or less constant”, says Dr Rasmussen.

Dr Arbøll and Dr Rasmussen conclude that future results emerging from research into ancient DNA, inevitably leading to discussions about complex historical developments and social interactions – such as kissing as a driver of early disease transmission - will benefit from an interdisciplinary approach.

Read the article “The ancient history of kissing” in Science.

Wednesday, May 17, 2023

Genetic analysis of Indigenous Taiwanese peoples sheds light on Austronesian expansion

 The Austronesian language family is one of the largest in the world, comprising over 1,200 languages spoken from Madagascar to Hawaii. Dang Liu, Albert Min-Shan Ko and Mark Stoneking collected genome-wide data from 55 individuals from seven Taiwanese Austronesian groups and two Han-Taiwanese groups to study the genetic structure of Taiwan, the point of origin for all Austronesian-speaking peoples. There are over 20 different Indigenous groups in Taiwan, divided into “highland” and “lowland” peoples. Many lowland peoples have intermarried with Han people, and their languages are endangered or extinct. For example, the lowland Makatao showed Han admixture dated within the past 100 years. A highland group known as the Atayal showed the most distinctive genetic profile, suggestive of considerable isolation from other groups in the last 3,000 years. By including published ancient genomes in their analyses, the authors inferred little divergence between the Into- and Out-of-Taiwan groups, with the latter and the present day highland groups showing additional interactions from northern East Asia. Austronesian people from outside Taiwan are most closely related to southern highland peoples in Taiwan. 

Exactly which Indigenous group is the parent of the Austronesian diaspora is still up for debate. Haplotype-based results suggest that the Amis are the source population, which accords with a recent linguistic analysis. However, a different approach, allele-based f4 comparisons, show that the Rukai share more ancestry with groups that left Taiwan than the Amis. The authors speculate that haplotype-based results for the Amis might reflect recent back-migration and contact. According to the authors, the results of the study demonstrate the importance of considering genetic structure within Taiwan when making inferences about the Into and Out of Taiwan events. 


South Africa's desert-like interior may have been more inviting to our human ancestors


Lining the Cape of South Africa and its southern coast are long chains of caves that nearly 200,000 years ago were surrounded by a lush landscape and plentiful food.

 

During a glacial phase that lasted between 195,000 to 123,000 years ago, these caves served as refuge to a group of humans that some researchers think were the only people to survive this ice age, called Marine Isotope Stage Six, or MIS6. And in this coastal region, a lot of archaeological research has taken place. Of less interest to archaeologists has been the interior of South Africa, which was thought to be an uninhabited, inhospitable place during at least two waves of ice ages, MIS3 and 2.

 

Now, a study has shown that the region might have been more fertile and temperate during these two glacial periods than previously thought, and that the region likely played host to human populations living around a series of paleolakes. The study, led by University of Michigan archaeologist Brian Stewart, provides a more comprehensive timeline of the age and stages of these lakes, and shows human fingerprints across the region. The research, funded by the National Geographic Society, is published in the journal PNAS.

 

"There's this perennial assumption that human population centers were always along the coast and that the interior, especially the southern interior of the Karoo Desert, were largely depopulated for long stretches of time," Stewart said. "The funny thing is that one just has to go into the interior and walk around and notice that there's archaeology everywhere."

 

But to flag the region as worthy of archaeological attention, the researchers needed to show that humans could have actually lived there. The research team, an international group including researchers from South Africa, the United Kingdom and France, examined a series of super flat areas of land ringed by higher ground. They showed that these regions, called "pans" in Afrikaans, are ancient lake beds, while the areas of higher elevation that encircle them are erosional landforms and sedimentary deposits left over from their ancient shorelines.

 

This suggests that these time periods were not as dry in this region as previously thought: there would have needed to have been sustained rainfall and humidity to keep these lakes full. The more temperate climate required to sustain lakes also meant the landscape was also able to sustain both vegetation and animals required to support human populations.

 

Reconstructing the paleolakes

 

The researchers used a variety of technologies to date and reconstruct these ancient lakes, shorelines and lake bottom deposits, and to recreate the landscape of the region. 

 

These include radiocarbon dating and a technique called luminescence, which measures the radioactivity of tiny crystals of quartz or feldspar that haven't seen the light of day since they were covered by sediment tens of thousands of years earlier. While buried, electrons from radioactive elements common to all sediments get trapped in these crystal matrices at a constant rate. By measuring how many electrons accumulated in the sample and comparing that to the degree of background radioactivity, the researchers can predict its age.

 

The researchers used these techniques to date columns of sedimentary lakeshore and lake bottom deposits, called lacustrine deposits, found surrounding and within a series of three pans dotted across a region some 100,000 square miles, about the size of Texas. They also aged the shells of freshwater mollusks found scattered throughout the region and embedded within the sedimentary lake deposits.

 

An aquatic gastropod, Tomichia ventricosa, found at a pan called Swartkolkvloer, was embedded in a column of lacustrine deposits. Together, the deposits and shells were radiocarbon dated to two time periods: approximately 39-55 thousand years before present, and approximately 31-34 thousand years before present.

 

At another pan called Grootvloer, the researchers found a freshwater mollusk called Unio caffer, which required "perennial freshwater" and the presence of fish to reproduce. These shells and lacustrine deposits in this pan were dated to between approximately 20-22 thousand years before present.

 

The researchers were also able to predict the area of land the lakes encompassed, as well as how deep they were, based on the height of the lacustrine deposits ringing their shorelines. For example, they determined that the paleolake at Swartkolkvloer was about 83 miles square and 59 feet deep, while the paleolake at Grootvloer was likely about 17 miles square and 62 feet deep. Another pan called Alexanderfontein, some 300 miles northeast near the town of Kimberley, held a lake about 13.5 miles square and 48 feet deep.

 

Based on these parameters, the researchers knew the lakes would have required a climate drastically different from the one that exists in South Africa's interior today. Using a hydrological model, they determined that evaporation rates within the region were between 20% and 25% lower than what they are today, while precipitation would have been more than 200% higher at Swartkolkvloer and 88% higher at Alexanderfontein.

 

"In various parts of the interior, between about 60 to about 12,000 years ago, we can see that there were enduring phases of pretty large bodies of water kicking around what used to be thought of as an arid and inhospitable environment," Stewart said. "This was a period that used to be thought of as notoriously dry and freezing cold in the winter. But we've got this evidence for these large lakes existing during this time period."

 

The researchers say current day regions that have similar climates and rates of precipitation and evaporation are likely northern Botswana, Zambia and Zimbabwe. Based on this estimation and data found from a contemporaneous site called Equus Cave, the researchers think large grazing and browsing mammals would have thrived in this region.

 

A complex, prehistoric people

 

Scattered alongside the lakes are human artifacts such as triangular points, bladelets, weathered ostrich shells and other assemblages. Much of these are from the Middle Stone Age, which ranged from about 280,000 years ago to about 25,000 years ago, and the Later Stone Age, which lasted from 25,000 years ago right up to European contact in the 15th century.

 

"There's Middle Stone Age archaeology just everywhere," Stewart said. "You can't drive anywhere and open the car door and not step on it. It's astounding how much there is."

 

Stewart says their findings could also expand the region where archaeologists think humans became more behaviorally complex. Over the past decades, researchers have found evidence that humans living in coastal South Africa started making the leap into complex thought, showing some of the earliest signs of behavioral complexity. It was thought that both climate and nutrient stability—including the rich omega fatty acids gleaned from seafood—allowed humans here to become behaviorally modern.

 

The group's work may challenge this idea by suggesting that favorable conditions for hunter-gatherers were not confined to the coastline but probably characterized many regions as climates changed, including the interior, current-day desert.

 

"Ours is a basin-wide study with much more macro scale implications. It also involves some of these areas that are just inland of this coastal and mountain belt that's dominated the archaeological narratives for so long," Stewart said. "Just inland of this area is a region that has been, for a long time, portrayed as hostile, and it just simply appears not to have been the case for big chunks of time—with the caveat that we need information on temperature depressions to understand how humans dealt with that." 

 

Stewart says next steps will be to return to the pans to study the archaeology throughout the region to understand better how humans lived in the area.

 

Study: Paleolakes and socioecological implications of glacial "greening" of the South African interior (available upon request)

 

Saturday, May 13, 2023

Ancient DNA reveals population continuity in pre-Hispanic central Mexico

 

Viridiana Villa-Islas and colleagues address this knowledge gap and present shotgun genome-wide data from 12 individuals and 27 mitochondrial genomes from 8 pre-Hispanic archaeological sites across Mexico, including 2 located at the shifting border between Aridoamerica and Mesoamerica. Contrary to archaeological data, Villa-Islas et al. revealed population continuity spanning the period of megadroughts and a broad preservation of the genetic structure across present-day Mexico for the last 2300 years – one that can still be observed in modern Indigenous populations. In addition, the authors also identify a contribution to pre-Hispanic populations of northern and central Mexico from two ancient unsampled “ghost” populations, demonstrating that the demographic events that gave rise to Aridoamerican and Mesoamerican populations are more complex than previously thought. 

In a related Perspective, Bastien Llamas and Xavier Roca-Rada highlight the study’s ethical and sustainable approach to paleogenomics. “The study of Villa-Islas et al. is a remarkable example of this approach because it targets a Global South region and is led and conducted by (predominantly) local researchers,” they write. “This is a considerable departure from collaboration between local scholars and laboratories from the Global North, which requires the export of samples and often leads to the relocation of local students and early-career researchers to the Global North for training.”

Human ancestors preferred mosaic landscapes and high ecosystem diversity



Fig. 1 

IMAGE: ARTIST ILLUSTRATION OF HOMININS ARRIVING IN A MULTI-BIOME MOSAIC LANDSCAPE. SUCH ENVIRONMENTS WERE GREATLY PREFERRED BY EARLY HUMANS, ACCORDING TO A NEW STUDY PUBLISHED IN THE JOURNAL SCIENCE BY A TEAM OF SCIENTISTS FROM SOUTH KOREA AND ITALY (COPYRIGHT, IBS CENTER FOR CLIMATE PHYSICS). view more 

CREDIT: INSTITUTE FOR BASIC SCIENCE

A new study published in the journal Science by an international team finds that early human species adapted to mosaic landscapes and diverse food resources, which would have increased our ancestor’s resilience to past shifts in climate.

Our genus Homo evolved over the past 3 million years – a period of increasing warm/cold climate fluctuations. How early human species have adapted to the intensification of climate extremes, ice ages, and large-scale shifts in landscapes and vegetation remains elusive. Did our ancestors adjust to local environmental changes over time, or did they seek out more stable environments with diverse food resources? Was our human evolution influenced more by temporal changes in climate, or by the spatial character of the environment?

To test these fundamental hypotheses on human evolution and adaptation quantitively, the research team used a compilation of more than three thousand well-dated human fossil specimens and archeological sites, representing six different human species, in combination with realistic climate and vegetation model simulations, covering the past 3 million years. The scientists focused their analysis on biomes – geographic regions which are characterized by similar climates, plants, and animal communities (e.g., savannah, rainforest, or tundra).

“For the archeological and anthropological sites and corresponding ages, we extracted the local biome types from our climate-driven vegetation model. This revealed which biomes were favored by the extinct hominin species H. ergaster, H. habilis, H. erectus, H. heidelbergensis, and H. neanderthalensis and by our direct ancestors - H. sapiens.”, said Elke Zeller, Ph.D. student from the IBS Center for Climate Physics at Pusan National University, South Korea, and lead author of the study.

According to their analysis, the scientists found that earlier African groups preferred to live in open environments, such as grassland and dry shrubland. Migrating into Eurasia around 1.8 million years ago, hominins, such as H. erectus and later H. heidelbergensis and H. neanderthalensis developed higher tolerances to other biomes over time, including temperate and boreal forests. “To survive as forest-dwellers, these groups developed more advanced stone tools and likely also social skills”, said Prof. Pasquale Raia, from the Università di Napoli Federico II, Italy, co-author of the study. Eventually, H. sapiens emerged around 200,000 years ago in Africa, quickly becoming the master of all trades. Mobile, flexible, and competitive, our direct ancestors, unlike any other species before, survived in harsh environments such as deserts and tundra.

When further looking into the preferred landscape characteristics, the scientists found a significant clustering of early human occupation sites in regions with increased biome diversity. “What that means is that our human ancestors had a liking for mosaic landscapes, with a great variety of plant and animal resources in close proximity”, said Prof. Axel Timmermann, co-author of the study and Director of the IBS Center for Climate Physics in South Korea. The results indicate that ecosystem diversity played a key role in human evolution.

The authors demonstrated this preference for mosaic landscapes for the first time on continental scales and propose a new Diversity Selection Hypothesis: Homo species, and H. sapiens, in particular, were uniquely equipped to exploit heterogeneous biomes. “Our analysis shows the crucial importance of landscape and plant diversity as a selective element for humans and as a potential driver for socio-cultural developments” adds Elke Zeller. Elucidating how vegetation shifts have shaped human sustenance, the new Science study provides an unprecedented view into human prehistory and survival strategies.

The climate and vegetation model simulations, which cover the Earth’s history of the past 3 million years, were conducted on one of South Korea’s fastest science supercomputers named Aleph. “Supercomputing is now emerging as a key tool in evolutionary biology and anthropology”, said Axel Timmermann.

Thursday, May 11, 2023

Tooth enamel provides clues to hunter-gatherer lifestyle of Neanderthals

 


A Neanderthal premolar tooth 

IMAGE: A NEANDERTHAL PREMOLAR TOOTH FROM THE ALMONDA CAVE SYSTEM, PORTUGAL, SEEN FROM DIFFERENT ANGLES. ISOTOPES OF STRONTIUM WERE USED TO TRACK THE MOVEMENT OF THIS INDIVIDUAL OVER THE 2 TO 3 YEARS THE ENAMEL TOOK TO FORM. view more 

CREDIT: JOÃO ZILHÃO

A study by an international team of researchers, led by the University of Southampton, has given an intriguing glimpse of the hunting habits and diets of Neanderthals and other humans living in western Europe.

The scientists examined chemical properties locked inside tooth enamel to piece together how pre-historic people lived off the land around the Almonda Cave system, near Torres Novas in central Portugal almost 100 thousand years ago.

Their findings, published in the journal PNAS, show Neanderthals in the region were hunting fairly large animals across wide tracts of land, whereas humans living in the same location tens of thousands of years later survived on smaller creatures in an area half the size.

Strontium isotopes in rocks gradually change over millions of years because of radioactive processes. This means they vary from place to place depending on the age of the underlying geology. As rocks weather, the isotopic ‘fingerprints’ are passed into plants via sediments, and make their way along the food chain – eventually passing into tooth enamel.

In this study, archaeologists used a technique which laser samples enamel and makes thousands of individual strontium isotope measurements along the growth of a tooth crown. Samples were taken from two Neanderthals, dating back about 95,000 years, and from a more recent human who lived about 13,000 years ago, during the Magdalenian period.

The scientists also looked at isotopes in the tooth enamel of animals found in the cave system. Alongside strontium, they measured oxygen isotopes, which vary seasonally from summer to winter. This enabled them to establish not only where the animals ranged across the landscape, but in which seasons they were available for hunting.

The team showed that the Neanderthals, who were targeting large animals, could have hunted wild goat in the summer, whereas horses, red deer and an extinct form of rhinoceros were available all year round within about 30km of the cave. The Magdalenian individual showed a different pattern of subsistence, with seasonal movement of about 20km from the Almonda caves to the banks of the Tagus River, and a diet which included rabbits, red deer, wild goat and freshwater fish.

The researchers approximated the territory of the two different human groups, revealing contrasting results. The Neanderthals obtained their food over approximately 600 km2, whereas the Magdalenian  individuals occupied a much smaller territory of about 300 km2.

Lead author, Dr Bethan Linscott who conducted the research while at the University of Southampton and who now works at the University of Oxford said: “Tooth enamel forms incrementally, and so represents a time series that records the geological origin of the food an individual ate.

“Using laser ablation, we can measure the variation of strontium isotopes over the two or three years it takes for the enamel to form. By comparing the strontium isotopes in the teeth with sediments collected at different locations in the region, we were able to map the movements of the Neanderthals and the Magdalenian individual. The geology around the Almonda caves is highly variable, making it possible to spot movement of just a few kms.”

Co-author, Professor Alistair Pike of the University of Southampton, who supervised the research said: “This study shows just how much science has changed our understanding of archaeology in the past decade. Previously, the lives and behaviours of past individuals was limited to what we could infer from marks on their bones or the artefacts they used. Now, using the chemistry of bones and teeth, we can begin to reconstruct individual life histories, even as far back as the Neanderthals.”

Co-author, Professor João Zilhão of the University of Lisbon, who led the excavation of the Almonda caves said: “The difference in the territory size between the Neanderthal and Magdalenian individuals is probably related to population density. With a relatively low population, Neanderthals were free to roam further to target large prey species, such as horses, without encountering rival groups.  By the Magdalenian period, an increase in population density reduced available territory, and human groups had moved down the food chain to occupy smaller territories, hunting mostly rabbits and catching fish on a seasonal basis.”

Tuesday, May 9, 2023

Nose shape gene inherited from Neanderthals


Skull nasal height comparison 

IMAGE: MODERN HUMAN AND ARCHAIC NEANDERTHAL SKULLS SIDE BY SIDE, SHOWING DIFFERENCE IN NASAL HEIGHT view more 

CREDIT: DR KAUSTUBH ADHIKARI, UCL

Humans inherited genetic material from Neanderthals that affects the shape of our noses, finds a new study led by UCL researchers.

The new Communications Biology study finds that a particular gene, which leads to a taller nose (from top to bottom), may have been the product of natural selection as ancient humans adapted to colder climates after leaving Africa.

Co-corresponding author Dr Kaustubh Adhikari (UCL Genetics, Evolution & Environment and The Open University) said: “In the last 15 years, since the Neanderthal genome has been sequenced, we have been able to learn that our own ancestors apparently interbred with Neanderthals, leaving us with little bits of their DNA.

“Here, we find that some DNA inherited from Neanderthals influences the shape of our faces. This could have been helpful to our ancestors, as it has been passed down for thousands of generations.”

The study used data from more than 6,000 volunteers across Latin America, of mixed European, Native American and African ancestry, who are part of the UCL-led CANDELA study, which recruited from Brazil, Colombia, Chile, Mexico and Peru. The researchers compared genetic information from the participants to photographs of their faces – specifically looking at distances between points on their faces, such as the tip of the nose or the edge of the lips – to see how different facial traits were associated with the presence of different genetic markers.

The researchers newly identified 33 genome regions associated with face shape, 26 of which they were able to replicate in comparisons with data from other ethnicities using participants in east Asia, Europe, or Africa.

In one genome region in particular, called ATF3, the researchers found that many people in their study with Native American ancestry (as well as others with east Asian ancestry from another cohort) had genetic material in this gene that was inherited from the Neanderthals, contributing to increased nasal height. They also found that this gene region has signs of natural selection, suggesting that it conferred an advantage for those carrying the genetic material.

First author Dr Qing Li (Fudan University) said: “It has long been speculated that the shape of our noses is determined by natural selection; as our noses can help us to regulate the temperature and humidity of the air we breathe in, different shaped noses may be better suited to different climates that our ancestors lived in. The gene we have identified here may have been inherited from Neanderthals to help humans adapt to colder climates as our ancestors moved out of Africa.”

Co-corresponding author Professor Andres Ruiz-Linares (Fudan University, UCL Genetics, Evolution & Environment, and Aix-Marseille University) added: “Most genetic studies of human diversity have investigated the genes of Europeans; our study’s diverse sample of Latin American participants broadens the reach of genetic study findings, helping us to better understand the genetics of all humans.”

The finding is the second discovery of DNA from archaic humans, distinct from Homo sapiens, affecting our face shape. The same team discovered in a 2021 paper that a gene influencing lip shape was inherited from the ancient Denisovans.*

The study involved researchers based in the UK, China, France, Argentina, Chile, Peru, Colombia, Mexico, Germany, and Brazil.

UCL News, 2021: Genes for face shape identified

Wednesday, May 3, 2023

Scientists recover an ancient woman’s DNA from a 20,000-year-old pendant

 

Pierced deer tooth 

IMAGE: PIERCED DEER TOOTH DISCOVERED FROM DENISOVA CAVE IN SOUTHERN SIBERIA THAT YIELDED ANCIENT HUMAN DNA. view more 

CREDIT: © MAX PLANCK INSTITUTE FOR EVOLUTIONARY ANTHROPOLOGY

Artefacts made of stone, bones or teeth provide important insights into the subsistence strategies of early humans, their behavior and culture. However, until now it has been difficult to attribute these artefacts to specific individuals, since burials and grave goods were very rare in the Palaeolithic. This has limited the possibilities of drawing conclusions about, for example, division of labor or the social roles of individuals during this period.

In order to directly link cultural objects to specific individuals and thus gain deeper insights into Paleolithic societies, an international, interdisciplinary research team, led by the Max Planck Institute for Evolutionary Anthropology in Leipzig, has developed a novel, non-destructive method for DNA isolation from bones and teeth. Although they are generally rarer than stone tools, the scientists focused specifically on artefacts made from skeletal elements, because these are more porous and are therefore more likely to retain DNA present in skin cells, sweat and other body fluids.

A new DNA extraction method

Before the team could work with real artefacts, they first had to ensure that the precious objects would not be damaged. “The surface structure of Paleolithic bone and tooth artefacts provides important information about their production and use. Therefore, preserving the integrity of the artefacts, including microstructures on their surface, was a top priority” says Marie Soressi, an archaeologist from the University of Leiden who supervised the work together with Matthias Meyer, a Max Planck geneticist.

The team tested the influence of various chemicals on the surface structure of archaeological bone and tooth pieces and developed a non-destructive phosphate-based method for DNA extraction. “One could say we have created a washing machine for ancient artifacts within our clean laboratory," explains Elena Essel, the lead author of the study who developed the method. "By washing the artifacts at temperatures of up to 90°C, we are able to extract DNA from the wash waters, while keeping the artifacts intact.”

Early setbacks

The team first applied the method to a set of artefacts from the French cave Quinçay excavated back in the 1970s to 1990s. Although in some cases it was possible to identify DNA from the animals from which the artefacts were made, the vast majority of the DNA obtained came from the people who had handled the artefacts during or after excavation. This made it difficult to identify ancient human DNA.

To overcome the problem of modern human contamination, the researchers then focused on material that had been freshly excavated using gloves and face masks and put into clean plastic bags with sediment still attached. Three tooth pendants from Bacho Kiro Cave in Bulgaria, home to the oldest securely dated modern humans in Europe, showed significantly lower levels of modern DNA contamination; however, no ancient human DNA could be identified in these samples.

A pendant from Denisova Cave

The breakthrough was finally enabled by Maxim Kozlikin and Michael Shunkov, archaeologists excavating the famous Denisova Cave in Russia. In 2019, unaware of the new method being developed in Leipzig, they cleanly excavated and set aside an Upper Paleolithic deer tooth pendant. From this, the geneticists in Leipzig isolated not only the DNA from the animal itself, a wapiti deer, but also large quantities of ancient human DNA. “The amount of human DNA we recovered from the pendant was extraordinary” says Elena Essel, “almost as if we had sampled a human tooth.”

Based on the analysis of mitochondrial DNA, the small part of the genome that is exclusively inherited from the mother to their children, the researchers concluded that most of the DNA likely originated from a single human individual. Using the wapiti and human mitochondrial genomes they were able to estimate the age of the pendant at 19,000 to 25,000 years, without sampling the precious object for C14 dating.

In addition to mitochondrial DNA, the researchers also recovered a substantial fraction of the nuclear genome of its human owner. Based on the number of X chromosomes they determined that the pendant was made, used or worn by a woman. They also found that this woman was genetically closely related to contemporaneous ancient individuals from further east in Siberia, the so called ‘Ancient North Eurasians’ for whom skeletal remains have previously been analyzed. “Forensic scientists will not be surprised that human DNA can be isolated from an object that has been handled a lot” says Matthias Meyer, “but it is amazing that this is still possible after 20,000 years.”

The scientists now hope to apply their method to many other objects made from bone and teeth in the Stone Age to learn more about the genetic ancestry and sex of the individuals who made, used, or wore them.