Friday, August 18, 2023

Ötzi: dark skin, bald head, Anatolian ancestry

 

Research team used advanced sequencing technology to analyze Ötzi’s genome to obtain a more accurate picture of the Iceman’s appearance and genetic origins

Peer-Reviewed Publication

MAX PLANCK INSTITUTE FOR EVOLUTIONARY ANTHROPOLOGY

Tyrolean Iceman 'Ötzi' 

IMAGE: SINCE 2012, WHICH IS WHEN ÖTZI’S GENOME WAS SEQUENCED FOR THE FIRST TIME, DNA SEQUENCING TECHNOLOGIES HAVE ADVANCED ENORMOUSLY. THIS NEW STUDY REVEALS THAT COMPARED TO OTHER CONTEMPORARY EUROPEANS, ÖTZI’S GENOME HAD AN UNUSUALLY HIGH PROPORTION OF GENES IN COMMON WITH THOSE OF EARLY FARMERS FROM ANATOLIA, THAT HIS SKIN WAS DARKER THAN PREVIOUSLY THOUGHT, AND THAT HE WAS LIKELY BALD OR HAD LITTLE HAIR ON HIS HEAD WHEN HE DIED. view more 

CREDIT: © SOUTH TYROL MUSEUM OF ARCHAEOLOGY/EURAC/MARCO SAMADELLI-GREGOR STASCHITZ

The genetic makeup of most present-day Europeans has resulted mainly from the admixture of three ancestral groups: western hunter-gatherers gradually merged with early farmers who migrated from Anatolia about 8,000 years ago and who were later on joined by Steppe Herders from Eastern Europe, approximately 4,900 years ago.

The initial analysis of the Iceman’s genome revealed genetic traces of these Steppe Herders. However, the refined new results no longer support this finding. The reason for the inaccuracy: the original sample had been contaminated with modern DNA. Since that first study, not only have sequencing technologies advanced enormously, but many more genomes of other prehistoric Europeans have been fully decoded, often from skeletal finds. This has made it possible to compare Ötzi’s genetic code with his contemporaries. The result: among the hundreds of early European people who lived at the same time as Ötzi and whose genomes are now available, Ötzi’s genome has more ancestry in common with early Anatolian farmers than any of his European counterparts.

Ötzi’s ancestry and appearance

The research team concludes that the Iceman came from a relatively isolated population that had very little contact with other European groups. “We were very surprised to find no traces of Eastern European Steppe Herders in the most recent analysis of the Iceman genome; the proportion of hunter-gatherer genes in Ötzi’s genome is also very low. Genetically, his ancestors seem to have arrived directly from Anatolia without mixing with hunter gatherer groups,” explains Johannes Krause, head of the Department of Archaeogenetics at the Max Planck Institute for Evolutionary Anthropology in Leipzig, and co-author of the study.

The study also yielded new results about Ötzi's appearance. His skin type, already determined in the first genome analysis to be Mediterranean-European, was even darker than previously thought. “It's the darkest skin tone that has been recorded in contemporary European individuals,” explains anthropologist Albert Zink, study co-author and head of the Eurac Research Institute for Mummy Studies in Bolzano: “It was previously thought that the mummy's skin had darkened during its preservation in the ice, but presumably what we see now is actually largely Ötzi's original skin color. Knowing this, of course, is also important for the proper conservation of the mummy.”

Our previous image of Ötzi is also incorrect regarding his hair: as a mature man, he most likely no longer had long, thick hair on his head, but at most a sparse crown of hair. His genes, in fact, show a predisposition to baldness. “This is a relatively clear result and could also explain why almost no hair was found on the mummy,” says Zink. Genes presenting an increased risk of obesity and type 2 diabetes were also found in Ötzi's genome, however, these factors probably did not come into play thanks to his healthy lifestyle.

Thursday, August 17, 2023

Japan's ancient practice of cranial modification: The case of the Hirota people in Tanegashima

 

Peer-Reviewed Publication

KYUSHU UNIVERSITY

Skeletal remains from the Hirota ruins 

IMAGE: A PHOTOGRAPH OF THE ANCIENT HUMAN REMAINS FOUND AT THE HIROTA RUINS. A NOTABLE CHARACTERISTIC OF THE REMAINS IS THE WEARING OF MANY SHELL ACCESSORIES, INDICATIVE OF THE CULTURE AND TRADE OF THE REGION AT THE TIME. view more 

CREDIT: THE KYUSHU UNIVERSITY MUSEUM

A team of biological anthropologists and archaeologists from Kyushu University and the University of Montana have broken new ground in our understanding on the practice of intentional cranial modification, a practice found in numerous ancient civilizations around the world.

Publishing in PLOS ONE, the team reports that the Hirota people, who lived on the southern Japanese island of Tanegashima around the 3rd century to 7th century CE, also partook in the practice. Moreover, the study found no significant differences in cranial modification between sexes, indicating that both males and females practiced intentional cranial modification.

Cranial modification is a form of body alteration where the head of a person is pressed or bound, usually at an early age, to permanently deform the skull. The practice predates written history, and researchers theorize that it was performed to signify group affiliation or demonstrate social status.

"One location in Japan that has long been associated with cranial deformation is the Hirota site on the Japanese island of Tanegashima, in Kagoshima Prefecture. This is a large-scale burial site of the Hirota people who lived there during the end of the Yayoi Period, around the 3rd century CE, to the Kofun Period, between the 5th and 7th century CE." explains Noriko Seguchi of Kyushu University's Faculty of Social and Cultural Studies who led the study. "This site was excavated from 1957 to 1959 and again from 2005 to 2006. From the initial excavation, we found remains with cranial deformations characterized by a short head and a flattened back of the skull, specifically the occipital bone and posterior parts of the parietal bones."

However, while the site provided an ideal opportunity to study the phenomenon, it had remained unclear whether these cranial modifications had been intentional, or were simply the unintended result of other habits.

To conduct the study, the research group employed a hybrid approach, utilizing 2D images to analyze the shape of the skulls' outline, as well as 3D scans of their surface. The group also compared crania data from other archeological sites in Japan, such as the Doigahama Yayoi people in Western Yamaguchi, and the Kyushu Island Jomon people, who were the hunter-gatherer predecessors to the Yayoi people. Along with visually assessing skull morphology, the team gathered all this data and statically analyzed the contours and shapes between the skulls.

"Our results revealed distinct cranial morphology and significant statistical variability between the Hirota individuals with the Kyushu Island Jomon and Doigahama Yayoi samples," continues Seguchi. "The presence of a flattened back of the skull characterized by changes in the occipital bone, along with depressions in parts of the skull that connects the bones together, specifically the sagittal and lambdoidal sutures, strongly suggested intentional cranial modification."

The motivations behind this practice remain unclear, but the researchers hypothesize that the Hirota people deformed their crania to preserve group identity and potentially facilitate long-distance trade of shellfish, as supported by archaeological evidence found at the site.

"Our findings significantly contribute to our understanding of the practice of intentional cranial modification in ancient societies," concludes Seguchi. "We hope that further investigations in the region will offer additional insights into the social and cultural significance of this practice in East Asia and the world."

###

For more information about this research, see "Investigating intentional cranial modification: A hybridized two-dimensional/three-dimensional study of the Hirota site, Tanegashima, Japan" Noriko Seguchi, James Frances Loftus III, Shiori Yonemoto, Mary-Margaret Murphy PLOS ONEhttps://doi.org/10.1371/journal.pone.0289219

Friday, August 11, 2023

Climate modeling reveals new insights into hominin migration and evolution

In two studies, researchers demonstrate how climate modeling approaches can fill gaps in our understanding of hominin evolution and migration.

Over the last several decades, research efforts into the lives of hominins – humans and their close ancestors – have shifted from identifying fossils and artifacts to understanding the environmental and climate settings in which they lived and how these factors could have influenced hominin evolution and migration. However, like the hominin fossil record, environmental and climate records that accurately capture environmental change and span the period over which hominins evolved and spread across the globe are uncommon and incomplete. Some of these limitations can be addressed through advances in analytical tools, particularly climate and ecosystem models, which can help fill these gaps and provide valuable new insights into hominin migration.

In one study, Vasiliki Margari and colleagues used a deep-sea sediment core, which provided a temperature record for Europe from 800,000 to 1.8 million years ago. Using these data, the authors created a climate envelope model and evaluated the geographic range of hominin species using climate variables such as temperature and precipitation. Margari et al. discovered hominin presence around the Mediterranean before ~1.1 million years ago was characterized by long, stable interglacial conditions with short glacials that would have allowed for hominin establishment and long-term occupation. However, extreme glacial conditions beginning around 1.1 million years ago would likely have made the region too cold for hominins to survive. Margari et al. argue that these extreme conditions likely led to the depopulation of Europe, which could have lasted for several glacial-interglacial cycles.

In another study, Jiaoyang Ruan and colleagues evaluate how climate shifts across central Eurasia during the Pleistocene could have facilitated interbreeding between Denisovans and Neanderthals. Genetic studies have revealed evidence of interbreeding between Neanderthals and Denisovans in Eurasia. However, much about these admixture events remains unknown. Here, Ruan et al. developed a species distribution model combining extensive fossil, archaeological, and genetic data with transient coupled general circulation model simulations of global climate and habitat change for the past 400,000 years, which was used to determine the habitat preferences for both Neanderthals and Denisovans. The authors found that, although both species lived in a variety of environments, Neanderthals preferred temperate forests, whereas Denisovans lived in a much wider range of habitats. However, orbitally driven climate shifts in habitat caused the preferred habitats of Denisovans and Neandertals to overlap, providing opportunities for interbreeding between the two species.


Extreme cooling ended the first human occupation of Europe


Peer-Reviewed Publication

UNIVERSITY COLLEGE LONDON

Extreme cooling ended the first human occupation of Europe 

VIDEO: VIDEO HIGHLIGHTING HOW PALEOCLIMATE EVIDENCE SHOWS THAT AROUND 1.1 MILLION YEARS AGO, THE SOUTHERN EUROPEAN CLIMATE COOLED SIGNIFICANTLY AND LIKELY CAUSED AN EXTINCTION OF EARLY HUMANS ON THE CONTINENT, ACCORDING TO A NEW STUDY LED BY UCL RESEARCHERS. view more 

CREDIT: UCL

Paleoclimate evidence shows that around 1.1 million years ago, the southern European climate cooled significantly and likely caused an extinction of early humans on the continent, according to a new study led by UCL researchers.

Published in the journal Science, the team of researchers discovered the occurrence of previously unknown extreme glacial conditions around 1.1 million years ago. The glacial cooling pushed the European climate to levels beyond what archaic humans could tolerate, emptying the continent of human populations.

The oldest known human remains in Europe have previously been recovered from Iberia and suggest that early humans had arrived from southwest Αsia by about 1.4 million years ago. The climate around that time would have generally been warm and wet, punctuated by mild cold periods. Up to now, the prevailing theory has been that once humans arrived, they were able to survive through multiple climate cycles and adapt to increasingly harsh conditions after 900,000 years ago.

Senior author Professor Chronis Tzedakis (UCL Geography) said: “Our discovery of an extreme glacial cooling event around 1.1 million years ago challenges the idea of continuous early human occupation of Europe.”

Paleoclimate scientists from UCL, University of Cambridge and CSIC Barcelona analysed the chemical composition of marine micro-organisms and examined the pollen content in a deep-sea sediment core recovered from off the coast of Portugal. This revealed the presence of abrupt climate changes that culminated in an extreme glacial cooling, with ocean surface temperatures off Lisbon dropping below 6°C and semi-deserts expanding on the adjacent land.

Lead author Dr Vasiliki Margari (UCL Geography) said: “To our surprise, we found that this cooling at 1.1 million years ago was comparable to some of the most severe events of recent ice ages.”

Co-author Professor Nick Ashton of the British Museum said: “A cooling of this magnitude would have placed small hunter-gatherer bands under considerable stress, especially since early humans may have lacked adaptations such as sufficient fat insulation and also the means to make fire, effective clothing or shelters.”

To assess the climate impact on early human populations, co-corresponding author Professor Axel Timmermann and his team from the IBS Center for Climate Physics at Pusan National University ran a climate simulation on their supercomputer Aleph to capture the extreme conditions during this time. Combining the output of the simulation with fossil and archaeological evidence of human occupation in southwest Eurasia, the team then developed a human habitat model, which predicts how suitable the environment was for early human occupation.

Professor Axel Timmermann said: “The results showed that 1.1 million years ago climate around the Mediterranean became too hostile for archaic humans.”

Together, the paleoclimate data and human habitat model results indicate that Iberia, and more generally southern Europe, was depopulated during the Early Pleistocene. An apparent lack of stone tools and human remains over the next 200,000 years further raises the possibility of a long-lasting hiatus in European occupation.

Co-author Professor Chris Stringer of the Natural History Museum in London said: “According to this scenario, Europe may have been recolonized around 900,000 years ago by more resilient humans with evolutionary or behavioural changes that allowed survival in the increasing intensity of glacial conditions.

Tuesday, August 8, 2023

Roman road network spanning South West England identified in new research


Peer-Reviewed Publication

UNIVERSITY OF EXETER

Roman nodes 

IMAGE: PRIMARY AND SECONDARY NODES IN THE STUDY AREA. view more 

CREDIT: UNIVERSITY OF EXETER

A Roman road network that spanned Devon and Cornwall and connected significant settlements with military forts across the two counties as well as wider Britannia has been discovered for the first time.

Archaeologists at the University of Exeter have used laser scans collected as part of the Environment Agency’s National LiDAR Programme to identify new sections of road west of the previously understood boundary.

Using sophisticated geographical modelling techniques, which incorporate information around gradients and flood risk, the researchers have then been able to map out the full extent of the network and begin to understand the rationale for its existence.

Among the things it reveals is that far from Exeter being the main nerve centre of the network, it was North Tawton that supported strategically vital connections with tidal estuaries north and south of Bodmin and Dartmoor.

These findings are explored in Remote Sensing and GIS Modelling of Roman Roads in South West Britain which has been published in the Journal of Computer Applications in Archaeology.

The research was led by Dr Christopher Smart and Dr João Fonte, specialists in landscape archaeology and the heritage of the Roman Empire, in Exeter’s Department of Archaeology and History. Dr César Parcero Oubiña, from the Institute of Heritage Sciences, Spanish National Research Council in Spain, specialist in geospatial technologies applied to archaeology, led the modelling of the Roman roads network.

“Despite more than 70 years of scholarship, published maps of the Roman road network in southern Britain have remained largely unchanged and all are consistent in showing that west of Exeter, Roman Isca, there was little solid evidence for a system of long-distance roads,” Dr Smart said. “But the recent availability of seamless LiDAR coverage for Britain has provided the means to transform our understanding of the Roman road network that developed within the province, and nowhere more so than in the far south western counties, in the territory of the Dumnonii.” 

The National LiDAR (Light Detection and Ranging) Programme was conducted between 2016 and 2022 by the Environment Agency covering the whole of England, and the data was made available via the DEFRA Data Services Platform. It transformed the amount of terrain mapped of Devon and Cornwall, which had previously stood at just 11%. The Exeter team, working with public volunteers, and funded by the National Lottery Heritage Fund as part of the Digital Skills for Heritage initiative, studied the scans and together they were able to map around 100km of additional roads.

Although this represented a significant advancement, the overall picture remained fragmented and patchy, with large portions of the map showing no evidence of Roman roads. So, the team developed a geographic information system predictive model, which could intelligently fill in the gaps as to the likely layout of the network.

Using an approach based upon Least Cost Paths – the optimal connections between two or more points – and other methods, such as focal mobility networks and transit corridors, the team began to plot primary and secondary ‘nodes’ across the two counties. These included permanent military fortifications, including the known forts of Old Burrow and The Beacon at Martinhoe, as well as the settlements at Exeter and North Tawton. They then calculated the easiest routes between these points. And when the team returned to the LiDAR scans, they were able to identify a further 13km of Roman road within a short distance predicted by the model.

The final stage saw the researchers use focal mobility networks and transit corridors to extend the road network to areas that lay beyond the main Roman sites known in the region, suggesting some secondary or tertiary routes alternative to the single best optimal path in the process. This established a number of new 'terminal points', particularly in the far west of Cornwall and along its south coast.

“In terms of chronology, it is likely that the proposed network is an amalgam of pre-existing Prehistoric routeways, Roman military campaign roads or “tactical roads” formally adopted into the provincial communications system, and of those constructed during peacetime in a wholly civilian context,” says Dr Fonte. “This evolutionary model is supported by the fact that the network does not solely connect Roman forts and their hinterlands directly, which are often connected by branch roads, but instead appears to serve a broader purpose than required by military supply.” 

The research concludes that the main rationale for the network was to facilitate animal-drawn vehicles and circumvent those areas where flooding was possible. It could also influence, say the authors, future archaeological research in the region.

“This network, identified by the scans and the GIS-enabled modelling, may serve to predict the location of settlements that are as yet unknown to us,” adds Dr Smart. “New archaeological evidence, including that proposed here for the existence of a wide-reaching Roman road network, urges for a reconsideration of the degree of capital investment in infrastructure and the development of a more complex settlement network hierarchy in the Roman South West Britain.”

Thursday, August 3, 2023

Ancient DNA reveals genetic lineage and legacy of African Americans from Catoctin Furnace, Maryland

Combining ancient DNA (aDNA) with data from the 23andMe genetic database, researchers have uncovered the lineage and legacy – including more than 40,000 living relatives – of free and enslaved African Am

ericans who labored at the Catoctin Iron Furnace in Maryland, between 1774 and 1850. “What makes the work … so pioneering is that the research was initiated by an engaged local community of African Americans and the results were structured to meet their needs, priorities, and sensibilities of the larger African American community,” writes Fatima Jackson in a related Perspective. “This is the way that this type of research should be performed, and it provides a blueprint for future studies.” 

The vast majority of Black and/or African American individuals living in the United States descended from the hundreds of thousands of enslaved Africans forcibly transported to the US between 1501 and 1867. However, due to the centuries of inhumane treatment of enslaved families and their descendants, historical records often omit details about the lives of these individuals. As a result, few contemporary African Americans have been able to trace family lineages back to their earliest enslaved ancestors in the United States. Ancient DNA technologies have the potential to provide insight into the identity of enslaved individuals and to restore lost familial histories. 

In this study, Éadaoin Harney and colleagues analyzed aDNA from 27 colonial African Americans interred at the Catoctin Furnace between 1774 and 1850. By comparing the genome-wide aDNA to data from more than 9.2 million participants in the 23andMe genetic database, the authors were able to draw identical-by-descent (IBD) connections between present-day and historical people. In addition to revealing five biological family groups amongst the Catoctin individuals, Harney et al.’s IBD-based approach identified 41,799 modern genetic relatives living throughout the US. One of the highest concentrations of close Catoctin relatives remains in Maryland. What’s more, the findings show that the Catoctin individuals are most closely related to small number of African groups, particularly the Wolof of West Africa and the Kongo of Central Africa.

Tuesday, August 1, 2023

Luzio, who lived in São Paulo 10,000 years ago, was Amerindian like Indigenous people now, DNA reveals

 

An investigation covering four different parts of Brazil carried out analysis of genomic data from 34 fossils, including larger skeletons and the famous mounds of shells and fishbones built on the coast, and revealed differences between communities


Luzio, who lived in São Paulo 10,000 years ago, was Amerindian like Indigenous people now 

IMAGE: THE INVESTIGATION THAT COVERED FOUR DIFFERENT PARTS OF BRAZIL CARRIED OUT ANALYSIS OF GENOMIC DATA FROM 34 FOSSILS, INCLUDING LARGER SKELETONS AND THE FAMOUS MOUNDS OF SHELLS AND FISHBONES BUILT ON THE COAST view more 

CREDIT: ANDRÉ STRAUSS

An article to be published on July 31 in Nature Ecology & Evolution reveals that Luzio, the oldest human skeleton found in São Paulo state (Brazil), was a descendant of the ancestral population that settled the Americas at least 16,000 years ago and gave rise to all present-day Indigenous peoples, such as the Tupi.

Based on the largest set of Brazilian archeological genomic data, the study reported in the article also offers an explanation for the disappearance of the oldest coastal communities, who built the icons of Brazilian archeology known as sambaquis, huge mounds of shells and fishbones used as dwellings, cemeteries and territorial boundaries. Archeologists often refer to these monuments as shell mounds or kitchen middens.

“After the Andean civilizations, the Atlantic coast sambaqui builders were the human phenomenon with the highest demographic density in pre-colonial South America. They were the ‘kings of the coast’ for thousands and thousands of years. They vanished suddenly about 2,000 years ago,” said André Menezes Strauss, an archeologist at the University of São Paulo’s Museum of Archeology and Ethnology (MAE-USP) and principal investigator for the study.

The first author of the article is Tiago Ferraz.The study was supported by FAPESP (projects 17/16451-2 and 20/06527-4) and conducted in partnership with researchers at the University of Tübingen’s Senckenberg Center for Human Evolution and Paleoenvironment (Germany).

The authors analyzed the genomes of 34 samples from four different areas of Brazil’s coast. The fossils were at least 10,000 years old. They came from sambaquis and other parts of eight sites (Cabeçuda, Capelinha, Cubatão, Limão, Jabuticabeira II, Palmeiras Xingu, Pedra do Alexandre and Vau Una).

This material included Luzio, São Paulo’s oldest skeleton, found in the Capelinha river midden in the Ribeira de Iguape valley by a group led by Levy Figuti, a professor at MAE-USP. The morphology of its skull is similar to that of Luzia, the oldest human fossil found to date in South America, dating from about 13,000 years ago. The researchers thought it might have belonged to a biologically different population from present-day Amerindians, who settled in what is now Brazil some 14,000 years ago, but it turns out they were mistaken.

“Genetic analysis showed Luzio to be an Amerindian, like the Tupi, Quechua or Cherokee. That doesn’t mean they’re all the same, but from a global perspective, they all derive from a single migratory wave that arrived in the Americas not more than 16,000 years ago. If there was another population here 30,000 years ago, it didn’t leave descendants among these groups,” Strauss said.

Luzio’s DNA also answered another question. River middens are different from coastal ones, so the find cannot be considered a direct ancestor of the huge classical sambaquis that appeared later. This discovery suggests there were two distinct migrations – into the hinterland and along the coast.

What happened to the sambaqui builders?

Analysis of the genetic material revealed heterogeneous communities with cultural similarities but significant biological differences, especially between coastal communities in the southeast and south.

“Studies of cranial morphology conducted in the 2000s had already pointed to a subtle difference between these communities, and our genetic analysis confirmed it,” Strauss said. “We discovered that one of the reasons was that these coastal populations weren’t isolated but ‘swapped genes’ with inland communities. Over thousands of years, this process must have contributed to the regional differences between sambaquis.”

Regarding the mysterious disappearance of this coastal civilization, comprising the first hunter-gatherers of the Holocene, analysis of the DNA samples clearly showed that, in contrast with the European Neolithic substitution of entire populations, what happened in this part of the world was a change of practices, with a decline in construction of shell middens and the introduction of pottery by sambaqui builders. For example, the genetic material found at Galheta IV (Santa Catarina state), the most emblematic site for the period, has remains not of shells but of ceramics and is similar to the classic sambaquis in this respect.

“This information is compatible with a 2014 study that analyzed pottery shards from sambaquis and found that the pots in question were used to cook not domesticated vegetables but fish. They appropriated technology from the hinterland to process food that was already traditional there,” Strauss said.