Category: Scientific News

Ina Reiche et al, “First discovery of charcoal-based prehistoric cave art in Dordogne”, Scientific reports, Nature, 22235 (2023).

https://www.nature.com/articles/s41598-023-47652-1#:~:text=A%20large%20number%20of%20Carbon,cave%2C%20Dordogne%2C%20Southern%20France

A study published in December 2023 in the journal Nature brings great satisfaction to all specialists in cave art. It reveals the discovery of parietal paintings using charcoal in the Font-de-Gaume cave (Eyzies-de-Tayac, Dordogne, France). The cave contains around 200 representations, two-thirds of which are animals and one-third geometric representations known as tectiforms. The majority of animal representations are of bison, followed by mammoths, deer and horses.

The importance of the presence of charcoal in the cave lies in the fact that, until now, it was assumed that Dordogne parietal paintings were made exclusively from mineral materials (iron oxides for red hues and manganese oxides for black hues). To date, however, it is impossible to carry out dating using mineral matter, hence the need for organic matter, i.e. charcoal.

The researchers used non-invasive physico-chemical analysis methods, such as Raman spectroscopy, to identify the presence of carbon in the paints without the risk of damaging them.

This exceptional discovery opens up the prospect of radiocarbon (carbon-14) dating of the Font-de-Gaume paintings, a first in the Dordogne. This would clarify the chronology of these works, currently dated to the Magdalenian period (around 19,000 – 12,500 B.C.).

Duane Hamacher, et al, “The archaeology of orality: Dating Tasmanian Aboriginal oral traditions to the Late Pleistocene”, Journal of Archaeological Science, 159 (2023).

https://www.sciencedirect.com/science/article/pii/S0305440323000997

Is it possible to date the age of certain oral traditions dating back to prehistoric times? That’s what a study published in November 2023 in the Journal of Archaeological Science proposes!

Focusing on the Aboriginal peoples living in Australia, researchers have demonstrated that Tasmanian oral traditions date back at least to the end of the Late Pleistocene. The methodology adopted consisted in examining traditions describing natural phenomena, which were correlated with geological, paleoenvironmental and astronomical studies in order to retrace the events thus described.

Current archaeological evidence points to the arrival ofHomo sapiens in Australia at least 65,000 years ago. Our species would have reached Tasmania around 40,000 years ago, before it broke away from the Australian continent.

The study in question focuses on Palawa and Pakana oral traditions, which were documented in the 1830s. Of these traditions, two elements caught the researchers’ attention: the submergence of a land bridge linking Tasmania to Australia, and the mention of a particularly bright star at the celestial south pole.

Using bathymetry (a technique for measuring the depth and relief of the ocean) and topography, researchers have estimated that the land bridge mentioned in the legend refers to the Bassian land bridge. This was submerged by rising waters around 12,000 years ago, separating Tasmania from Australia. The star itself has been identified as Canopus. Researchers calculated its declination during the last precession to estimate when it was at its minimum, a position where it would have appeared particularly bright at the south celestial pole from Tasmania. This has been estimated at around 14,000 BC.

Thus, provided that these traditions accurately reflect events, this study indicates that Tasmanian oral traditions date back at least to the end of the Upper Pleistocene, between 12,000 and 14,000 years BC. This shows that oral traditions can be perpetuated over thousands of years, opening up new perspectives in what is known as oral archaeology.

Chris O. Hunt et al, “Shanidar and his flowers? Reflections on the palynology of the Neanderthal ‘Flower Burial’ hypothesis”, Journal of Archaeological Science, 159 (2023).

https://www.sciencedirect.com/science/article/pii/S0305440323001024

The Shanidar site is well known in prehistory, being one of the earliest sites where Neanderthal burials have been unearthed, raising questions about possible symbolic practices on the part of Neanderthal Man. One particular burial, that of the male individual named Shanidar 4, raises questions, as according to researchers at the time, he was buried on a bed of flowers. This conclusion is based on the analysis of pollens taken from inside the tomb, belonging to different species of flowers currently present around the site.

However, a new palynological study (the study of pollen in archaeological contexts) published in November 2023 in the Journal of Archaeological Science calls this scenario into question.

Indeed, the researchers put forward several arguments against the idea of an individual being laid on a bed of flowers:

• First of all, the different flower species identified are not present in the vicinity of the cave at the same time (at least not at present, and climatic and environmental conditions have changed little). Consequently, it seems unlikely that Neanderthal individuals could have collected these flowers and placed them in the burial site at the same time;
• The burial site remained open for a year before being excavated, giving ample time for contemporary contamination by pollen from the surrounding flowers;
• According to the researchers, the mixture of pollens is more likely the result of an accumulation by solitary bees, which accidentally deposited the pollen they were carrying in the soil. In fact, numerous bee burrows have been discovered in the cave floor.

Consequently, it seems unlikely that the presence of pollen in this burial is the result of a bed of flowers on which the Neanderthal individual would have been laid. This does not, however, detract from the archaeological importance of this burial site.

Rivollat et al, “Extensive pedigree reveal the social organization of a Neolithic community”, Nature, vol. 620, August 2023.

https://www.nature.com/articles/s41586-023-06350-8

In prehistory, the kinship systems that may have existed within communities can only be studied thanks to the archaeological and biological remains discovered during excavations. The study of isotopes, sex and age of buried individuals can provide information on the demographic structure of the population studied when it constitutes a funerary community. Genetics also plays a role in these studies, making it possible to determine family relationships, for example.

This is the conclusion of a study recently published in the journal Nature, which analyzed the genomes of over 100 individuals from the Gurgy “les Noisats” burial site (France). The site has been dated to between 4850 and 4500 BC.

The study highlighted several aspects of the community’s social organization. Thus, there are 2 main family groups: Group A, comprising 64 individuals, all related to each other and spanning 7 generations, and Group B, comprising 12 individuals, also all related to each other and spanning 5 generations.

The different generations are mainly linked by male ancestry. In fact, all descendants are linked by the paternal line of the first generation. Furthermore, with the exception of 2 individuals, no adult mothers have relatives or ancestors buried in this community. This, coupled with the fact that very few female individuals are descendants of the two main groups, suggests that this community was patrilineal, with an exogenous origin of the women in the group.

As far as the organization of burials is concerned, it has been shown that family ties influenced their layout. For example, burials between a father and son are physically much closer than those of other family members. The same applies to relationships other than father-son. The^4th generation siblings were all buried close together. In another example, an adult mother’s son was buried above her. In this way, the spatial organization of burials forms organized groupings according to the more or less close kinship links between individuals.

Finally, the high number of adult siblings suggests a relatively low mortality rate among children.

This burial site was only occupied for a few decades.

Wang et al., “High-coverage genome of the Tyrolean Iceman reveals unusually high Anatolian farmer ancestry”, Cell Genomics 3, 100377, August 2023.

https://www.cell.com/cell-genomics/pdf/S2666-979X(23)00174-X.pdf

Une nouvelle étude du génome d’Ötzi vient d’être publiée dans la revue Cell Genomics ! Cette étude remet en question certains résultats obtenus lors d’une précédente étude génétique réalisée en 2012.

Depuis 2012, les techniques et méthodes d’analyses ont évolué et permettent désormais de séquencer de manière plus fiable de l’ADN ancien, où les problèmes de conservation et contamination limitent souvent les études. C’est dans cette optique qu’une équipe de généticiens a de nouveau séquencé le génome de celui qui est surnommé « homme des glaces ». Un prélèvement a été effectué  au niveau de l’os iliaque gauche de la momie et les chercheurs ont utilisé une méthode de séquençage plus performante: la méthode Illumina.

Ötzi a été découvert en 1991 par hasard par des randonneurs à 3 210 mètres d’altitude dans le glacier du Hauslabjoch dans les Alpes de l’Ötzal, d’où son surnom Ötzi. Daté d’il y a environ 3350-3120 ans avant notre ère, soit environ – 5 300 ans, cet homme aurait tué par une flèche et se serait ensuite naturellement momifié grâce au froid. La conservation exceptionnelle des restes ont permis de réaliser de nombreuses analyses, qui se poursuivent encore aujourd’hui.

Ötzi est généralement décrit comme ayant des cheveux longs et une peau pâle, mais cette nouvelle étude vient contredire ces affirmations puisqu’ Ötzi avait en réalité une peau foncée et peu de cheveux, il présente en effet des marqueurs génétiques associés avec la calvitie masculine. Ces derniers étaient noirs. Ces caractères phénotypiques correspondent en effet à l’apparence actuelle de la momie. Les analyses ont également révélé qu’Ötzi possède des allèles associés à un risque de diabète de type 2 et d’obésité.

En ce qui concerne son ascendance, Ötzi possède un bagage génétique provenant principalement des premiers agriculteurs néolithiques venant d’Anatolie. Cette population se serait métissée avec des chasseurs-cueilleurs de l’ouest de l’Europe, et c’est de cette combinaison dont descendrait Ötzi, puisque ce métissage peut être retracé jusqu’à environ 56 générations plus tôt dans son génome.

Marquet el al, “The earliest unambiguous Neandethal engravings on cave walls: La Roche-Cotard, Loire Valley, France”, PLoS ONE 18(6): e0286568, 2023.

https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0286568

An article was recently published in the journal PlosOne reporting the discovery of engravings made by Homo neanderthalensis at the La Roche-Cotard cave. This cave, located in the Touraine region, more precisely at Langeais in Indre-et-Loire, was discovered in 1846. Several excavations were carried out on this site in 1912, in the 1970s and in 2008. This study reveals that the cave was first occupied by carnivores, then by humans and finally by hyenas, before the entrance was blocked and the cave became inaccessible until its discovery in 1846.

The human beings who lived in this cave were Neanderthals. How do we know? Thanks to dating, scientists have been able to determine that the cave entrance was blocked by sediment around 57,000 years ago. Consequently, this cave was occupied over 57,000 years ago, and at that time our species, Homo sapiens, had not yet arrived in Europe, the only species present being Homo neanderthalensis. What’s more, the tools found at the site are typical of the Mousterian, a culture strictly associated with Neanderthal in Europe.

Several marks and traces have been identified on the cave walls. These have been classified according to their origin. This ranking was based on experiments and statistical studies. Some of the marks are carnivore claw marks, but some are man-made and correspond to digital tracings. Digital tracings are lines or geometric shapes created with the fingers on an initially soft surface. This type of tracery is part of the various forms of cave art and can be found at other sites in Europe and South Africa, for example. The authors conclude that these tracings are the result of a creative process within the cave. This discovery proves, if proof were needed, that Neanderthals were capable of artistic, and perhaps even symbolic, practices!

Wiseman LA. 2023 Three-dimensional volumetric muscle reconstruction of the Australopithecus afarensis pelvis and limb, with estimations of limb leverage. R. Soc. Open. Sci. 10:2303556.

https://royalsocietypublishing.org/doi/10.1098/rsos.230356

Researchers have reconstructed the muscle mass ofAustralopithecus afarensis Lucy, dated at 3.2 million years. This one, discovered in 1974 at the Hadar site in Ethiopia, provided us with a very complete skeleton, with almost 40% of the bones found. The various studies carried out on Lucy’s skeleton have shown that she was certainly capable of bipedalism, while continuing to climb trees to get around. However, these studies were carried out on bones, not muscles. Although researchers have been trying for some years to reconstruct the muscles of certain Hominins in order to deduce elements about their locomotion, this approach was limited by the complexity of the mathematical models to be set up.

In this new study, researchers try a new approach to reconstruct 36 muscles of the Australopithecus pelvis and lower limbs. To do this, they used the anatomy of Homo sapiens individuals to infer muscle positioning in Lucy. This new 3D model of Lucy’s muscles shows that she had much more massive and developed muscles than today’s Homo sapiens. What’s more, the study shows that, although certain muscles were positioned differently in Australopithecus than in our species, they enabled Lucy to stand in an erect position. However, his bipedalism differed from ours in the positioning of certain muscles. It was also capable of other modes of locomotion, such as arboricolgy.

https://www.nature.com/articles/d41586-023-02242-z?fbclid=IwAR1i0t0Dod1bnTGO2cmGAwNDg16h_CNoBjUIcetMFsYCEhV3drnpRGYSrtE

A 2-million-year-old protein sequence (later abbreviated to Ma) has just been successfully sequenced and analyzed! This is the conclusion of an article published on the bioRxiv server, which allows articles to be put online before the peer review process is completed on July 3, 2023. These protein sequences come from several teeth of individuals belonging to the Paranthropus robustus species. These teeth were found in a cave in South Africa. This is an exceptional discovery. In fact, studies on ancient DNA do not allow us to go back as far as 2 Ma, as DNA does not keep well over time and is particularly sensitive to heat. For example, the oldest sequenced hominin DNA is dated to around 430,000 years ago in Europe. We’re a long way from 2 Ma!

In recent years, the study of protein sequences has emerged as an alternative to the difficulties encountered in paleogenetics. Proteins are better preserved over time and directly reflect the genome, since they are made from our DNA sequence. In this study, the researchers succeeded in determining the sex of the Paranthropus individuals studied. In fact, they found traces of a protein called Y-amelogenin on 2 teeth. This protein is produced by a gene on the Y chromosome, indicating that these two individuals are male. In contrast, the other two teeth do not display this protein, but rather a protein present only on the X chromosome, suggesting that the teeth belong to females. Such a breakthrough in paleoproteomics looks promising. However, care must be taken, as this article is not “officially” published in a journal, as it has not yet passed the peer review stage, i.e. verification by other researchers of the quality of the study carried out.

Marc R. Meyer et al, “Knuckle-walking in Sahelanthropus? Locomotor inferences from the ulnae of fossil hominins and other hominoids”, Journal of Human Evolution, vol. 179, 2023

https://www.sciencedirect.com/science/article/abs/pii/S0047248423000325

The debate over whether Toumaï, whose scientific name is Sahelanthropus tchadensis, belongs to the Hominins is still raging, and a new article may well provide the final blow.

Sahelanthropus tchadensis was discovered in 2001 at Toros-Menalla in Chad. Dated at around 7 million years, it is one of the 3 candidates for the title of oldest representative of the human lineage. For some researchers, Toumaï is indeed a member of the Hominins, since he was bipedal. Its bipedalism is confirmed by the anterior position of the foramen magnum, similar to that found in our own species. For other researchers, Toumaï is not bipedal and therefore not a Hominin. One of the arguments put forward, for example, is the conformation of the femur, which resembles a chimpanzee femur more than aHomo sapiens femur.

However, an article published in the Journal of Human Evolution has reshuffled the deck, demonstrating that Toumaï was in fact a significant knuckle-walker. To achieve this, the study carried out combined analyses of the conformation of the diaphysis and the proximal complex of the ulna. The results show that the ulna of S. tchadensis displays typical knuckle-walking characteristics. The authors propose 2 hypotheses to justify such a result. The first is that S. tchadensis is a very ancient Hominin having “retained” knuckle-walking behavior. The second is that Toumaï is indeed not a Hominin, but practiced knuckle-walking like that found in chimpanzees. However, such results need to be confirmed.

Dong et al, “Dual domestications and origin of traits in grapevine evolution” Science 379, 892-901, 2023

https://www.science.org/doi/10.1126/science.add8655

A study published in the journal Science sets back the domestication of the vine by almost 3,000 years! To achieve this result, the authors genetically sequenced 3,525 vine samples, including 2,503 from Vitis vinifera (the domestic vine) and 1,022 from Vitis sylvestris (the wild vine). Genetic data and statistical analysis have shed light on many aspects of the vine’s history.

The wild vine, Vitis sylvestris, split into 2 lineages in response to climatic fluctuations during the Pleistocene. A first line is developing in the Caucasus region and Western Asia (named Syl-E), while a second line is developing in Central Europe and the Iberian Peninsula (named Syl-W). Surprisingly, two independent but concomitant domestication events took place from the Syl-E lineage, giving rise to the domesticated vine, Vitis vinifera. A first center of domestication emerged in the Caucasus for vines used to make wine. The second center of domestication appears in Western Asia for table grapes. This calls into question the then-accepted view that vines for wine production were domesticated before vines for table grapes.

The domestication of the vine therefore took place in the east of our continent, in the Caucasus and in western Asia. This is estimated to be 11,000 years old, compared with 8,000 years ago. So the domestication of the vine took place very early on, at the same time as the beginnings of agriculture! Grapevines then spread along human migration routes in Europe and North Africa. Various interbreeding events took place between the Syl-E and Syl-W groups, contributing to a diversification of grape types.