Tag Archives: #neanderthals

Psychiatry

Creativity And Community: How Modern Humans Overcame the Neanderthals? (Psychiatry)

Leave a comment

Study identifies creativity genes that set Homo sapiens apart from close living and extinct relatives

A new study is the first-ever to identify the genes for creativity in Homo sapiens that distinguish modern humans from chimpanzees and Neanderthals. The research identified 267 genes that are found only in modern humans and likely play an important role in the evolution of the behavioral characteristics that set apart Homo sapiens, including creativity, self-awareness, cooperativeness, and healthy longevity. The study, led by an international and interdisciplinary team of researchers from the American Museum of Natural History and Washington University among other institutions, is published today in the journal Molecular Psychiatry.

“One of the most fundamental questions about human nature is what sparked the explosive emergence of creativity in modern humans in the period just before and after their widespread dispersal from Africa and the related extinction of Neanderthals and other human relatives,” said study co-author Ian Tattersall, curator emeritus in the American Museum of Natural History’s Division of Anthropology. “Major controversies persist about the basis for human creativity in art and science, as well as about potential differences in cognition, language, and personality that distinguish modern humans from extinct hominids. This new study is the result of a truly pathbreaking use of genomic methodologies to enlighten us about the mechanisms underpinning our uniqueness.”

Modern humans demonstrate remarkable creativity compared to their closest living relatives, the great apes (chimpanzees, gorillas, and orangutans and their immediate ancestors), including innovativeness, flexibility, depth of planning, and related cognitive abilities for symbolism and self-awareness that also enable spontaneous generation of narrative art and language. But the genetic basis for the emergence of creativity in modern humans remains a mystery, even after the recovery of full-genome data for both chimpanzees and our extinct close relatives the Neanderthals.

“It has been difficult to identify the genes that led to the emergence of human creativity before now because of the large number of changes in the human genome after it diverged from the common ancestor of humans and chimpanzees around 10 million years ago, as well as uncertainty about the functions of those changes,” said Robert Cloninger, a psychiatrist and geneticist at Washington University in St. Louis, and the lead author of the study. “Therefore, we began our research by first identifying the way the genes that influence modern human personality are organized into coordinated systems of learning that have allowed us to adapt flexibly and creatively to changing life conditions.”

The team led by Cloninger had previously identified 972 genes that regulate gene expression for human personality, which is comprised of three nearly separate networks for learning and memory. One, for regulating emotional reactivity–emotional drives, habit learning, social attachment, conflict resolution–emerged in monkeys and apes about 40 million years ago. The second, which regulates intentional self-control–self-directedness and cooperation for mutual benefit–emerged a little less than 2 million years ago. A third one, for creative self-awareness, emerged about 100,000 years ago.

In the latest study, the researchers discovered that 267 genes from this larger group are found only in modern humans and not in chimpanzees or Neanderthals. These uniquely human genes code for the self-awareness brain network and also regulate processes that allow Homo sapiens to be creative in narrative art and science, to be more prosocial, and to live longer lives through greater resistance to aging, injury, and illness than the now-extinct hominids they replaced.

Genes regulating emotional reactivity were nearly the same in humans, Neanderthals, and chimps. And Neanderthals were about midway between chimps and Homo sapiens in their genes for self-control and self-awareness.

“We found that the adaptability and well-being of Neanderthals was about 60 to 70 percent of that of Homo sapiens, which means that the difference in fitness between them was large,” Cloninger said. “After the more creative, sociable, and physically resilient Homo sapiens migrated out of Africa between 65,000 and 55,000 years ago, they displaced Neanderthals and other hominids, who all became extinct soon after 40,000 years ago.”

The genes that distinguish modern humans from Neanderthals and chimpanzees are nearly all regulatory genes made of RNA, not protein-coding genes made of DNA.

“The protein-coding genes of Homo sapiens, Neanderthals, and chimps are nearly all the same, and what distinguishes these species is the regulation of the expression of their protein-coding genes by the genes found only in humans,” said co-author Igor Zwir, a computer scientist at Washington University School of Medicine and the University of Granada. “We found that the regulatory genes unique to modern humans were constituents of clusters together with particular protein-coding genes that are overexpressed in the human brain network for self-awareness. The self-awareness network is essential to the physical, mental, and social well-being of humans because it provides the insight to regulate our habits in accord with our goals and values.”

The researchers determined that the genes unique to modern humans were selected because of advantages tied to greater creativity, prosocial behavior, and healthy longevity. Living longer, healthier lives and being more prosocial and altruistic allowed Homo sapiens to support their children, grandchildren, and others in their communities throughout their lives in diverse and sometimes harsh conditions. And being more innovative than other hominids allowed humans to adapt more flexibly to unpredictable climatic fluctuations.

“In the bigger picture, this study helps us understand how we can effectively respond to the challenges that modern humans currently face,” Tattersall said. “Our behavior is not fixed or determined by our genes. Indeed, human creativity, prosociality, and healthy longevity emerged in the context of the need to adjust rapidly to harsh and diverse conditions and to communicate in large social groups.”

Added co-author Coral del Val of the University of Granada, “Now, we face similar challenges to which we must also respond creatively, as we did originally. Unfortunately, when we are exposed to conditions of fear, conflict, inequity, abuse or neglect, our self-awareness is impaired, which diminishes our ability to use our potential for creativity and to achieve well-being. Learning more about the regulatory genes unique to modern humans may help us to promote human well-being as we face these new environmental and social challenges.”

Featured image: From left, a chimpanzee, a modern human, and a reconstructed Neanderthal in the American Museum of Natural History’s Anne and Bernard Spitzer Hall of Human Origins. © D. Finnin/©AMNH

Reference: Zwir, I., Del-Val, C., Hintsanen, M. et al. Evolution of genetic networks for human creativity. Mol Psychiatry (2021). https://doi.org/10.1038/s41380-021-01097-y

Provided by American Museum of Natural History

Archaeology

Neanderthals Disappeared from North West Europe Earlier Than Thought (Archeology)

Leave a comment

Neanderthal remains from Belgium are thousands of years older than previously reported, a new paper from a multidisciplinary team of international researchers reveals.

Neanderthal remains from Belgium have long puzzled scientists. Fossil remains from the key site of Spy Cave in Belgium suggested a date of approximately 37,000 years ago, which would place them among the latest surviving Neanderthals in Europe. But sample contamination might have affected these estimates.

Now, a team based in Oxford’s Radiocarbon Accelerator Unit has re-dated Neanderthal specimens from Spy Cave. Most of the dates obtained in this new study have been found to be much older than those obtained previously on the same bone samples—up to 5,000 years older in certain cases

According to the paper, Re-evaluating the timing of Neanderthal disappearance in Northwest Europe, this suggests Neanderthals disappeared from the region 44,200-40,600 years ago, much earlier than previously estimated.

“The results suggest again that Homo sapiens and Neanderthals probably overlapped in different parts of Europe and there must have been opportunities for possible cultural and genetic exchange“

— Professor Tom Higham

Oxford Professor Tom Higham says, ‘Dating is crucial in archaeology, without a reliable framework of chronology we can’t really be confident in understanding the relationships between Neanderthals and Homo sapiens as we moved into Europe 45,000 years ago and they began to disappear. That’s why these methods are so exciting, because they provide much more accurate and reliable dates. The results suggest again that Homo sapiens and Neanderthals probably overlapped in different parts of Europe and there must have been opportunities for possible cultural and genetic exchange.’

Lead author, Dr Thibaut Devièse says, ‘The new chemistry methods we have applied in the case of the Spy and other Belgian sites provide the only means by which we can decontaminate these key Neanderthal bones for dating and check that contaminants have been fully removed. This gives us confidence in the new ages we obtained for these important specimens.’

Grégory Abrams, of the Scladina Cave Archaeological Centre in Belgium says, ‘We also (re)dated Neanderthal specimens from two additional Belgian sites, Fonds-de-Forêt and Engis, and obtained similar ages than those from Spy. Dating all these Belgian specimens was very exciting as they played a major role in the understanding and the definition of Neanderthals. Almost two centuries after the discovery of the Neanderthal child of Engis, we were able to provide a reliable age.’

“Dating all these Belgian specimens was very exciting as they played a major role in the understanding and the definition of Neanderthals“

The team found a Neanderthal scapula from the Spy Cave that had produced very recent dates previously (around 28,000 years ago) was heavily contaminated with modern bovine DNA. These results suggest that the bone had been preserved with a glue prepared from cattle bones.

The team used an advanced method for radiocarbon dating fossil bones. Using liquid chromatography separation, they were able to extract a single amino acid from the Neanderthal remains for dating. This so-called ‘compound-specific’ approach allows scientists to reliably date the bones and exclude carbon from contaminants such as those from the glue that was applied to the fossils. These contaminants have plagued previous attempts to reliably date the Belgian Neanderthals because their presence resulted in dates that were much too young.

The results also highlight the need for robust pre-treatment methods when dating Palaeolithic human remains to minimize biases due to contamination, according to the authors. The team is now analysing archaeological evidence, such as bone tools, to further refine our understanding of the cultural transition between Neanderthals and Homo sapiens in this region.

Featured image: Maxilla and mandible assemblage of a late Neanderthal from Spy Cave. Illustration by Patrick Semal © RBINS (co-author on this paper).

Reference: Thibaut Devièse, Grégory Abrams, Mateja Hajdinjak, Stéphane Pirson, Isabelle De Groote, Kévin Di Modica, Michel Toussaint, Valentin Fischer, Dan Comeskey, Luke Spindler, Matthias Meyer, Patrick Semal, Tom Higham, “Reevaluating the timing of Neanderthal disappearance in Northwest Europe”, Proceedings of the National Academy of Sciences Mar 2021, 118 (12) e2022466118; DOI: 10.1073/pnas.2022466118

Provided by University of Oxford

Archaeology

Neanderthals and Homo sapiens used Identical Nubian Technology (Archeology)

Leave a comment

New analysis of a fossil tooth and stone tools from Shukbah Cave reveals Neanderthals used stone tool technologies thought to have been unique to modern humans

Long held in a private collection, the newly analysed tooth of an approximately 9-year-old Neanderthal child marks the hominin’s southernmost known range. Analysis of the associated archaeological assemblage suggests Neanderthals used Nubian Levallois technology, previously thought to be restricted to Homo sapiens. 

With a high concentration of cave sites harbouring evidence of past populations and their behaviour, the Levant is a major centre for human origins research. For over a century, archaeological excavations in the Levant have produced human fossils and stone tool assemblages that reveal landscapes inhabited by both Neanderthals and Homo sapiens, making this region a potential mixing ground between populations. Distinguishing these populations by stone tool assemblages alone is difficult, but one technology, the distinct Nubian Levallois method, is argued to have been produced only by Homo sapiens.

In a new study published in Scientific Reports, researchers from the Max Planck Institute for the Science of Human History teamed up with international partners to re-examine the fossil and archaeological record of Shukbah Cave. Their findings extend the southernmost known range of Neanderthals and suggest that our now-extinct relatives made use of a technology previously argued to be a trademark of modern humans. This study marks the first time the lone human tooth from the site has been studied in detail, in combination with a major comparative study examining the stone tool assemblage. 

“Sites where hominin fossils are directly associated with stone tool assemblages remain a rarity – but the study of both fossils and tools is critical for understanding hominin occupations of Shukbah Cave and the larger region,” says lead author Dr Jimbob Blinkhorn, formerly of Royal Holloway, University of London and now with the Pan-African Evolution Research Group (Max Planck Institute for the Science of Human History).

Photo and 3D reconstruction of a tooth of a 9-year-old Neanderthal child © Trustees of the Natural History Museum, London © Blinkhorn, et al., 2021

Shukbah Cave was first excavated in the spring of 1928 by Dorothy Garrod, who reported a rich assemblage of animal bones and Mousterian-style stone tools cemented in breccia deposits, often concentrated in well-marked hearths. She also identified a large, unique human molar. However, the specimen was kept in a private collection for most of the 20th century, prohibiting comparative studies using modern methods. The recent re-identification of the tooth at the Natural History Museum in London has led to new detailed work on the Shukbah collections.  

“Professor Garrod immediately saw how distinctive this tooth was. We’ve examined the size, shape and both the external and internal 3D structure of the tooth, and compared that to Holocene and Pleistocene Homo sapiens and Neanderthal specimens. This has enabled us to clearly characterise the tooth as belonging to an approximately 9 year old Neanderthal child,” says Dr. Clément Zanolli, from Université de Bordeaux. “Shukbah marks the southernmost extent of the Neanderthal range known to date,” adds Zanolli.

Although Homo sapiens and Neanderthals shared the use of a wide suite of stone tool technologies, Nubian Levallois technology has recently been argued to have been exclusively used by Homo sapiens. The argument has been made particularly in southwest Asia, where Nubian Levallois tools have been used to track human dispersals in the absence of fossils.

Photos of Nubian Levallois cores associated with Neanderthal fossils © UCL, Institute of Archaeology & courtesy of the Penn Museum, University of Pennsylvania © Blinkhorn, et al., 2021 / CC BY 4.0

“Illustrations of the stone tool collections from Shukbah hinted at the presence of Nubian Levallois technology so we revisited the collections to investigate further. In the end, we identified many more artefacts produced using the Nubian Levallois methods than we had anticipated,” says Blinkhorn. “This is the first time they’ve been found in direct association with Neanderthal fossils, which suggests we can’t make a simple link between this technology and Homo sapiens.”

“Southwest Asia is a dynamic region in terms of hominin demography, behaviour and environmental change, and may be particularly important to examine interactions between Neanderthals and Homo sapiens,” adds Prof Simon Blockley, of Royal Holloway, University of London. “This study highlights the geographic range of Neanderthal populations and their behavioural flexibility, but also issues a timely note of caution that there are no straightforward links between particular hominins and specific stone tool technologies.”

“Up to now we have no direct evidence of a Neanderthal presence in Africa,” said Prof Chris Stringer of the Natural History Museum. “But the southerly location of Shukbah, only about 400 km from Cairo, should remind us that they may have even dispersed into Africa at times.”

Partnerships

Researchers involved in this study include scholars from the Max Planck Institute for the Science of Human History, Royal Holloway, University of London, the Université de Bordeaux, the Max Planck Institute for Chemical Ecology, the University of Malta, and the Natural History Museum, London. This work was supported by the Leverhulme trust (RPH-2017-087).

Featured image: The view from Shukbah Cave © Amos Frumkin

Reference: James Blinkhorn, Clément Zanolli, Tim Compton, Huw S. Groucutt, Eleanor M.L. Scerri, Lucile Crété, Chris Stringer, Michael D. Petraglia, Simon Blockley, “Nubian Levallois technology associated with southernmost Neanderthals”, Scientific Reports, 2021. https://www.nature.com/articles/s41598-021-82257-6

Provided by Max Planck Institute for the Science of Human History

Paleontology

How A Single Gene Alteration May Have Separated Modern Humans From Predecessors (Paleontology)

Leave a comment

Novel study used brain organoids genetically modified to mimic now-extinct Neanderthals

As a professor of pediatrics and cellular and molecular medicine at University of California San Diego School of Medicine, Alysson R. Muotri, PhD, has long studied how the brain develops and what goes wrong in neurological disorders. For almost as long, he has also been curious about the evolution of the human brain — what changed that makes us so different from preceding Neanderthals and Denisovans, our closest evolutionary relatives, now extinct?

Evolutionary studies rely heavily on two tools — genetics and fossil analysis — to explore how a species changes over time. But neither approach can reveal much about brain development and function because brains do not fossilize, Muotri said. There is no physical record to study.

So Muotri decided to try stem cells, a tool not often applied in evolutionary reconstructions. Stem cells, the self-renewing precursors of other cell types, can be used to build brain organoids — “mini brains” in a laboratory dish. Muotri and colleagues have pioneered the use of stem cells to compare humans to other primates, such as chimpanzees and bonobos, but until now a comparison with extinct species was not thought possible.

In a study published February 11, 2021 in Science, Muotri’s team catalogued the differences between the genomes of diverse modern human populations and the Neanderthals and Denisovans, who lived during the Pleistocene Epoch, approximately 2.6 million to 11,700 years ago. Mimicking an alteration they found in one gene, the researchers used stem cells to engineer “Neanderthal-ized” brain organoids.

“It’s fascinating to see that a single base-pair alteration in human DNA can change how the brain is wired,” said Muotri, senior author of the study and director of the UC San Diego Stem Cell Program and a member of the Sanford Consortium for Regenerative Medicine. “We don’t know exactly how and when in our evolutionary history that change occurred. But it seems to be significant, and could help explain some of our modern capabilities in social behavior, language, adaptation, creativity and use of technology.”

The team initially found 61 genes that differed between modern humans and our extinct relatives. One of these altered genes — NOVA1 — caught Muotri’s attention because it’s a master gene regulator, influencing many other genes during early brain development. The researchers used CRISPR gene editing to engineer modern human stem cells with the Neanderthal-like mutation in NOVA1. Then they coaxed the stem cells into forming brain cells and ultimately Neanderthal-ized brain organoids.

Brain organoids are little clusters of brain cells formed by stem cells, but they aren’t exactly brains (for one, they lack connections to other organ systems, such as blood vessels). Yet organoids are useful models for studying genetics, disease development and responses to infections and therapeutic drugs. Muotri’s team has even optimized the brain organoid-building process to achieve organized electrical oscillatory waves similar to those produced by the human brain.

The Neanderthal-ized brain organoids looked very different than modern human brain organoids, even to the naked eye. They had a distinctly different shape. Peering deeper, the team found that modern and Neanderthal-ized brain organoids also differ in the way their cells proliferate and how their synapses — the connections between neurons — form. Even the proteins involved in synapses differed. And electrical impulses displayed higher activity at earlier stages, but didn’t synchronize in networks in Neanderthal-ized brain organoids.

Alysson R. Muotri, PhD, is a professor at University of California San Diego School of Medicine. © UC San Diego Health Sciences

According to Muotri, the neural network changes in Neanderthal-ized brain organoids parallel the way newborn non-human primates acquire new abilities more rapidly than human newborns.

“This study focused on only one gene that differed between modern humans and our extinct relatives. Next we want to take a look at the other 60 genes, and what happens when each, or a combination of two or more, are altered,” Muotri said.

“We’re looking forward to this new combination of stem cell biology, neuroscience and paleogenomics. The ability to apply the comparative approach of modern humans to other extinct hominins, such as Neanderthals and Denisovans, using brain organoids carrying ancestral genetic variants is an entirely new field of study.”

To continue this work, Muotri has teamed up with Katerina Semendeferi, professor of anthropology at UC San Diego and study co-author, to co-direct the new UC San Diego Archealization Center, or ArchC.

“We will merge and integrate this amazing stem cell work with anatomic comparisons from several species and neurological conditions to create downstream hypotheses about brain function of our extinct relatives,” Semendeferi said. “This neuro-archealization approach will complement efforts to understand the mind of our ancestors and close relatives, like the Neanderthals.”

Featured image: Neanderthal-ized brain organoids (left) look very different than modern human brain organoids (right) — they have a distinctly different shape, and differ in the way their cells proliferate and how their synapses form. © UC San Diego Health Sciences

Reference: Cleber A. Trujillo, Edward S. Rice, Nathan K. Schaefer, Isaac A. Chaim, Emily C. Wheeler, Assael A. Madrigal, Justin Buchanan, Sebastian Preissl, Allen Wang, Priscilla D. Negraes, Ryan A. Szeto, Roberto H. Herai, Alik Huseynov, Mariana S. A. Ferraz, Fernando S. Borges, Alexandre H. Kihara, Ashley Byrne, Maximillian Marin, Christopher Vollmers, Angela N. Brooks, Jonathan D. Lautz, Katerina Semendeferi, Beth Shapiro, Gene W. Yeo, Stephen E. P. Smith, Richard E. Green, Alysson R. Muotri, “Reintroduction of the archaic variant of NOVA1 in cortical organoids alters neurodevelopment”, Science 12 Feb 2021: Vol. 371, Issue 6530, eaax2537 DOI: 10.1126/science.aax2537

Provided by University of California-San Deigo

Biology

Neanderthals Gut Microbiota And The Bacteria Helping Our Health (Biology)

Leave a comment

Neanderthals’ gut microbiota already included some beneficial micro-organisms that are also found in our own intestine. An international research group led by the University of Bologna achieved this result by extracting and analysing ancient DNA from 50,000-year-old faecal sediments sampled at the archaeological site of El Salt, near Alicante (Spain).

Published in Communication Biology, their paper puts forward the hypothesis of the existence of ancestral components of human microbiota that have been living in the human gastrointestinal tract since before the separation between the Homo Sapiens and Neanderthals that occurred more than 700,000 years ago.

“These results allow us to understand which components of the human gut microbiota are essential for our health, as they are integral elements of our biology also from an evolutionary point of view” explains Marco Candela, the professor of the Department of Pharmacy and Biotechnology of the University of Bologna, who coordinated the study. “Nowadays there is a progressive reduction of our microbiota diversity due to the context of our modern life: this research group’s findings could guide us in devising diet- and lifestyle-tailored solutions to counteract this phenomenon”.

THE ISSUES OF THE “MODERN” MICROBIOTA

The gut microbiota is the collection of trillions of symbiont micro-organisms that populate our gastrointestinal tract. It represents an essential component of our biology and carries out important functions in our bodies, such as regulating our metabolism and immune system and protecting us from pathogenic micro-organisms.

Recent studies have shown how some features of modernity – such as the consumption of processed food, drug use, life in hyper-sanitized environments – lead to a critical reduction of biodiversity in the gut microbiota. This depletion is mainly due to the loss of a set of microorganisms referred to as “old friends”.

“The process of depletion of the gut microbiota in modern western urban populations could represent a significant wake-up call,” says Simone Rampelli, who is a researcher at the University of Bologna and first author of the study. “This depletion process would become particularly alarming if it involved the loss of those microbiota components that are crucial to our physiology”.

Indeed, there are some alarming signs. For example, in the West, we are witnessing a dramatic increase in cases of chronic inflammatory diseases, such as inflammatory bowel disease, metabolic syndrome, type 2 diabetes and colorectal cancer.

HOW THE “ANCIENT” MICROBIOTA CAN HELP

How can we identify the components of the gut microbiota that are more important for our health? And how can we protect them with targeted solutions? This was the starting point behind the idea of identifying the ancestral traits of our microbiota – i.e. the core of the human gut microbiota, which has remained consistent throughout our evolutionary history. Technology nowadays allows to successfully rise to this challenge thanks to a new scientific field, paleomicrobiology, which studies ancient microorganisms from archaeological remains through DNA sequencing.

The research group analysed ancient DNA samples collected in El Salt (Spain), a site where many Neanderthals lived. To be more precise, they analysed the ancient DNA extracted from 50,000 years old sedimentary faeces (the oldest sample of faecal material available to date). In this way, they managed to piece together the composition of the micro-organisms populating the intestine of Neanderthals. By comparing the composition of the Neanderthals’ microbiota to ours, many similarities aroused.

“Through the analysis of ancient DNA, we were able to isolate a core of microorganisms shared with modern Homo sapiens”, explains Silvia Turroni, researcher at the University of Bologna and first author of the study. “This finding allows us to state that these ancient micro-organisms populated the intestine of our species before the separation between Sapiens and Neanderthals, which occurred about 700,000 years ago”.

SAFEGUARDING THE MICROBIOTA

These ancestral components of the human gut microbiota include many well-known bacteria (among which Blautia, Dorea, Roseburia, Ruminococcus and Faecalibacterium) that are fundamental to our health. Indeed, by producing short-chain fatty acids from dietary fibre, these bacteria regulate our metabolic and immune balance. There is also the Bifidobacterium: a microorganism playing a key role in regulating our immune defences, especially in early childhood. Finally, in the Neanderthal gut microbiota, researchers identified some of those “old friends”. This confirms the researchers’ hypotheses about the ancestral nature of these components and their recent depletion in the human gut microbiota due to our modern life context.

“In the current modernization scenario, in which there is a progressive reduction of microbiota diversity, this information could guide integrated diet- and lifestyle-tailored strategies to safeguard the micro-organisms that are fundamental to our health”, concludes Candela. “To this end, promoting lifestyles that are sustainable for our gut microbiota is of the utmost importance, as it will help maintain the configurations that are compatible with our biology”.

Featured image: The research group analysed the ancient DNA extracted from 50,000 years old sedimentary faeces (the oldest sample of faecal material available to date). The samples were collected in El Salt (Spain), a site where many Neanderthals lived. © University of Bologna

Reference: Rampelli, S., Turroni, S., Mallol, C. et al. Components of a Neanderthal gut microbiome recovered from fecal sediments from El Salt. Commun Biol 4, 169 (2021). https://www.nature.com/articles/s42003-021-01689-y https://doi.org/10.1038/s42003-021-01689-y

Provided by University of Bologna

Archaeology

New Evidence: Neanderthals Buried Their Dead (Archeology)

Leave a comment

Was burial of the dead practiced by Neandertals or is it an innovation specific to our species? There are indications in favour of the first hypothesis but some scientists remain sceptical. For the first time in Europe, however, a multi-disciplinary team led by researchers at the CNRS and the Muséum national d’histoire naturelle (France) and the University of the Basque Country (Spain) (1) has demonstrated, using a variety of criteria, that a Neandertal child was buried, probably around 41,000 years ago, at the Ferrassie site (Dordogne). Their study is published in the journal Scientific Reports on 9th December 2020.

Examining material from the 1970s excavations at the Musée d’archéologie nationale, France. Thousands of bone remains were sorted and 47 new fossil remains belonging to the Neandertal child ‘La Ferrassie 8’ were identified. © Antoine Balzeau – CNRS/MNHN

Dozens of buried Neandertal skeletons have been discovered in Eurasia, leading some scientists to deduce that, like us, Neandertals buried their dead. Other experts have been sceptical, however, given that the majority of the best-preserved skeletons, found at the beginning of the 20th century, were not excavated using modern archaeological techniques.

It is within this framework that an international team (1) led by paleoanthropologists Antoine Balzeau (CNRS and Muséum national d’histoire naturelle, France) and Asier Gómez-Olivencia (University of the Basque Country, Spain), analysed a human skeleton from one of the most famous Neandertal sites in France: the La Ferrassie rock shelter, Dordogne. After six Neandertal skeletons were discovered at the beginning of the 20th century, the site delivered a seventh between 1970 and 1973, belonging to a child of around two years old. For almost half a century, the collections associated with this specimen remained unexploited in the archives of the Musée d’archéologie nationale.

Reconstruction of the child’s burial by Neandertals at La Ferrassie (Dordogne, France). © Emmanuel Roudier

Recently, a multidisciplinary team, assembled by the two researchers, reopened the excavation notebooks and reviewed the material, revealing 47 new human bones not identified during excavation and undoubtedly belonging to the same skeleton. The scientists also carried out a thorough analysis of the bones: state of preservation, study of proteins, genetics, dating, etc. They returned to La Ferrassie in the hope of finding further fragments of the skeleton; although no new bones were discovered, using the notebooks of their predecessors, they were able to reconstruct and interpret the spatial distribution of the human remains and the rare associated animal bones.

The researchers showed that the skeleton had been buried in a sedimentary layer which inclined to the west (the head, to the east, was higher than the pelvis), while the other stratigraphic layers of the site inclined to the north-east. The bones, which were relatively unscattered, had remained in their anatomical position. Their preservation, better than that of the bison and other herbivores found in the same stratum, indicates a rapid burial after death. Furthermore, the contents of this layer proved to be earlier than the surrounding sediment (2). Finally, a tiny bone, identified as human by the proteins and as Neandertal by its mitochondrial DNA, was directly dated using carbon-14. At around 41,000 years old, this makes it one of the most recent directly dated Neandertal remains.

This new information proves that the body of this two-year-old Neandertal child was purposefully deposited in a pit dug in a sedimentary layer around 41,000 years ago; however, further discoveries will be necessary to understand the chronology and geographical extension of Neandertal burial practices.

Reference: Antoine Balzeau, Alain Turq, Sahra Talamo, Camille Daujeard, Guillaume Guérin, Frido Welker, Isabelle Crevecoeur, Helen Fewlass, Jean-Jacques Hublin, Christelle Lahaye, Bruno Maureille, Matthias Meyer, Catherine Schwab, Asier Gómez-Olivencia. Pluridisciplinary evidence for burial for the La Ferrassie 8 Neandertal child. Scientific Reports, 2020; 10 (1) DOI: 10.1038/s41598-020-77611-z

Provided by CNRS

Archaeology

Videoscope Analysis of a Neanderthal Skeleton Reveals Detailed Dental Information (Archeology)

Leave a comment

The Neanderthal specimen from Lamalunga Cave, near Altamura (Apulia, Italy), was discovered during a speleological survey in 1993. The specimen is one of the most complete fossil hominins in Europe and its state of preservation is exceptional, although it is stuck in calcareous concretions and the bones are mostly covered by calcite depositions. Nevertheless, it is possible to carry out some observations on craniodental features that have not previously been described.

An image of the skull, combined with a detail of the palate, with the maxillary teeth visible. © Soprintendenza ABAP per la Città metropolitana di Bari.

Now, Riga and colleagues presented an account of the oral cavity, made possible by the use of a videoscope, which allowed them to reach some hidden parts of the mandible and palate. This is the first detailed overview of the teeth and maxillary bones of the Neanderthal skeleton from Altamura.

The dentition is almost complete. However, two teeth (upper right P3 and upper left M1) were lost ante mortem and four teeth (lower right I1 and P3 and lower left I1 and I2) were lost most probably post mortem. Dental wear is marked. The erupted M3s and the inversion of the compensating curve of Wilson in the M1s and M2s but not in the M3s suggest that the individual is fully adult, but not old.

Although most of the teeth have their roots exposed for several millimeters, the periodontal bone appears to be in good condition overall, except in correspondence of the two ante-mortem tooth losses. X-rays of the anterior teeth showed a periapical lesion, probably linked to the advanced dental wear. They also observed a weak expression of taurodontism in the posterior dentition and the presence of a retromolar space, features consistent with an attribution to the Neanderthal hypodigm; this attribution is also supported by aspects of the cranial morphology, the morphometric analysis of the scapula and preliminary mtDNA data. There is also a well-developed palatine torus, to the best of their knowledge a feature not previously described in Neanderthals.

This work was supported by Ministero dell’Istruzione, dell’Università e della Ricerca, PRIN 2015 grant to G.M., J.M.-C. and D.M., number 2015WPHSCJ, prin.miur.it. The Soprintendenza A.B.A.P. per la città metropolitana di Bari (formerly Soprintendenza Archeologia per la Puglia); the “G. Sergi” Museum of Anthropology (Sapienza University of Rome) and the Museo delle Civiltà (section “L. Pigorini”, Rome) granted access to fossil specimens. The company Olympus (Olympus Italia S.r.l. and Olympus Europe) provided the endoscopic equipment. DentaForm S.r.l. (Pistoia, Italy) provided the NOMAD™ Pro 2 X-ray system and the KaVo ScanXam™. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.

References: Riga A, Boggioni M, Papini A, Buzi C, Profico A, Di Vincenzo F, et al. (2020) In situ observations on the dentition and oral cavity of the Neanderthal skeleton from Altamura (Italy). PLoS ONE 15(12): e0241713. doi:10.1371/journal.pone.0241713 https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0241713

Provided by PLOS journal

Paleontology

Climate Change Likely Drove Early Human Species To Extinction, Modeling Study Suggests (Paleontology)

Leave a comment

Of the six or more different species of early humans, all belonging to the genus Homo, only we Homo sapiens have managed to survive. Now, a study reported in the journal One Earth on October 15 combining climate modeling and the fossil record in search of clues to what led to all those earlier extinctions of our ancient ancestors suggests that climate change–the inability to adapt to either warming or cooling temperatures–likely played a major role in sealing their fate.

“Our findings show that despite technological innovations including the use of fire and refined stone tools, the formation of complex social networks, and–in the case of Neanderthals–even the production of glued spear points, fitted clothes, and a good amount of cultural and genetic exchange with Homo sapiens, past Homo species could not survive intense climate change,” says Pasquale Raia of Università di Napoli Federico II in Napoli, Italy. “They tried hard; they made for the warmest places in reach as the climate got cold, but at the end of the day, that wasn’t enough.”

To shed light on past extinctions of Homo species including H. habilis, H. ergaster, H. erectus, H. heidelbergensis, H. neanderthalensis, and H. sapiens, the researchers relied on a high-resolution past climate emulator, which provides temperature, rainfall, and other data over the last 5 million years. They also looked to an extensive fossil database spanning more than 2,750 archaeological records to model the evolution of Homo species’ climatic niche over time. The goal was to understand the climate preferences of those early humans and how they reacted to changes in climate.

Their studies offer robust evidence that three Homo species–H. erectus, H. heidelbergensis, and H. neanderthalensis–lost a significant portion of their climatic niche just before going extinct. They report that this reduction coincided with sharp, unfavorable changes in the global climate. In the case of Neanderthals, things were likely made even worse by competition with H. sapiens.

“We were surprised by the regularity of the effect of climate change,” Raia says. “It was crystal clear, for the extinct species and for them only, that climatic conditions were just too extreme just before extinction and only in that particular moment.”

Raia notes that there is uncertainty in paleoclimatic reconstruction, the identification of fossil remains at the level of species, and the aging of fossil sites. But, he says, the main insights “hold true under all assumptions.” The findings may serve as a kind of warning to humans today as we face unprecedented changes in the climate, Raia says.

“It is worrisome to discover that our ancestors, which were no less impressive in terms of mental power as compared to any other species on Earth, could not resist climate change,” he said. “And we found that just when our own species is sawing the branch we’re sitting on by causing climate change. I personally take this as a thunderous warning message. Climate change made Homo vulnerable and hapless in the past, and this may just be happening again.”

Provided by Cell Press

Paleontology

Neanderthals Have Adopted Male Sex Chromosome From Modern Humans (Paleontology)

Leave a comment

Ancient DNA has provided new insights into many aspects of human history. However, we lack comprehensive studies of the Y chromosomes of Denisovans and Neanderthals because the majority of specimens that have been sequenced to sufficient coverage are female. In the recent study, researchers sequenced and compared the genomes of archaic hominins with that of modern humans.

The researchers in their study identified three male Neanderthals and two Denisovans that were potentially suitable for DNA analysis, and developed an approach to fish out human Y chromosome molecules from the large amounts of microbial DNA that typically contaminate ancient bones and teeth. This allowed them to reconstruct the Y chromosome sequences of these individuals, which would not have been possible using conventional approaches.

Upper molar of a male Neandertal (Spy 94a) from Spy, Belgium. Credit: I. Crevecoeur

By comparing the genomes of archaic hominins with that of modern humans, they showed that the Y chromosomes of Denisovans split around 700 thousand years ago from a lineage shared by Neanderthals and modern human Y chromosomes, which diverged from each other around 370 thousand years ago.

It is by now well established that all people with non-African ancestry carry a small amount of Neanderthal DNA as a result of interbreeding between Neanderthals and modern humans approximately 50,000-70,000 years ago, quite shortly after modern humans migrated out of Africa and started spreading around the world. However, whether Neandertals might also carry some modern human DNA has been a matter of some debate.

These Y chromosome sequences now provide new evidence that Neandertals and early modern humans met and exchanged genes before the major out of Africa migration—potentially as early as 370,000 years ago and certainly more than 100,000 years ago. This implies that some population closely related to early modern humans must already have been in Eurasia at that time. Surprisingly, this interbreeding resulted in the replacement of the original Neandertal Y chromosomes with those of early modern humans, a pattern similar to what has been seen for Neandertal mitochondrial DNA in an earlier study.

References: Martin Petr, “The evolutionary history of Neanderthal and Denisovan Y chromosomes”, Science 25 Sep 2020, Vol. 369, Issue 6511, pp. 1653-1656 DOI: 10.1126/science.abb6460 link: https://science.sciencemag.org/content/369/6511/1653