Category: Scientific News

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.

Braga et al, “Hominin fossils from Kromdraai and Drimolen inform Paranthropus robustus craniofacial ontogeny”, Sci. Adv. 9, 3 May 2023

https://www.science.org/doi/10.1126/sciadv.ade7165

Fossil cranial remains of four immature (=juvenile) individuals belonging to the species Paranthropus robustus have been discovered at the Kromdraai and Drimolen sites in South Africa. This is an exceptional discovery, since it is the first time that immature fossils belonging to this species have been found. The Paranthropus robustus species, which lived between 2.2 and 1.2 million years ago in South Africa, is characterized by particularly robust cranial features. The study of these immature individuals sheds light on the craniofacial development of this species, which is so different from our own. Indeed, we know very little about the ontogenic development of other Hominin species, and tend to infer data from what we know about our own species, Homo sapiens. However, it is highly probable that the developments were different! This discovery also enables us to compare the development of Paranthropus robustus with another Hominin species for which an immature has also been discovered, Australopithecus africanus.

Published in May 2023 in the journal Science Advances, the study shows that most of the facial morphological features ofParanthropus robustus appear late in development.

Art- Ivo Verheijen et al, “Early evidence for bear exploitation during MIS 9 from the site of Schöningen 12 (Germany)”

Journal of Human Evolution 177 (2023) 103294

A recent study demonstrates the exploitation of bears at a site dated to the Lower Paleolithic, the Schöningen site in Germany. This site, already known for its extremely well-preserved archaeological artifacts of organic material, provides new evidence of bear exploitation at a time when such artifacts are rare. Indeed, most traces of bear exploitation date from the Late Pleistocene, as for example at the site of Hohle fels in Germany. The fossil remains of bears found in Schöningen belong to the species Ursus thibetanus, the Asiatic black bear, and to the species Ursus deningeri/spealeus, the cave bear lineage.

These remains represent 10% of the faunal assemblage at the site and the two fossils of most interest here are a metatarsal and a phalanx that show evidence of cutting. These traces were observed under the microscope and their locations, characteristics and similarities with fossils from other sites indicate that they are the result of a butchering to recover the animal’s skin, perhaps to make a fur. Moreover, since the bear skin had to be collected quickly after the death of the animal in order to be exploited, this indicates an active hunting of the bear by the Hominins. During the Paleolithic period, the bear was omnipresent in Europe during both cold and warm periods.

These results will have to be confirmed with the discovery of other remains, but the question of the exploitation of the bear, whether for its meat or for its skin, is important in the study of the subsistence behaviors of Hominins in Europe.

Read the full article here

Art – Kaedan O’Brien, Nicholas Hebdon, J. Tyler Faith, “Paleoecological evidence for environmental specialization in Paranthropus boisei compared to early Homo”

Journal of Human Evolution 177 (2023), 103325

Available online April 2023

Between 2.7 and 1.2 million years ago (later abbreviated to Ma), several species of hominins coexisted in Africa. This was the case, for example, of Paranthropus boisei, a species that became extinct around 1.2 Ma and is characterized by extremely developed cranial structures, and Homo habilis, the first species belonging to the genus Homo that emerged around 2.8 Ma. A recurring question is the ecological niches occupied by these species. It is commonly accepted thatHomo habilis is more ecologically flexible and adapts to different types of environments while Paranthropus boisei is more “specialized” to one type of environment. Nevertheless, it is difficult to test this hypothesis quantitatively. This is why this study proposes to quantify these environmental associations based on the study of faunal assemblages (=a set of fossils belonging to non-human animals), and more particularly of cattle.

Indeed, animal species, like plant species, are dependent on a climate and an environment. Researchers used Hominin fossils and faunal assemblages from the Koobi Fora Formation (Kenya, Africa). Indeed, this site has delivered a significant quantity of animal fossils dated between 1.98 and 1.38 Ma as well as remains of Hominins present in these same archaeological levels. This important fauna allows us to establish a high resolution of the environmental variability at this time. In this study, statistical methods are used to determine if there is a relationship between the type of environment and the Hominin species studied.

We must be careful here about conservation biases between the different faunal assemblages studied, but the results show that Homo habilis does indeed seem to occupy a greater variety of environments, ranging from dry savannah-type environments to grasslands, via forest environments. Conversely, P. boisei seems to be more restricted to a wooded savannah type environment.

Read the full article here

Christopher J. Knüsel, Adrien Thibeault, Sébastien Villotte, “A cranial injury from the earliest Gravettian at the Cro-Magnon rock shelter (Vézère Valley, Dordogne, southwest France)”

Journal of Human Evolution 177 (2023) 103329

Available online 2 March 2023

A new study of the cranium of the specimen named Cro-Magnon 2 shows that the impact present at the level of the frontal of this individual is the result of an ante-mortem wound. The remains of the individuals nicknamed “Cro-Magnon men” were discovered in 1868 at Eyzies-de-Tailhac in Dordogne (France) at the Cro-Magnon shelter.

It is besides the name of this shelter which will give the nickname “Cro-Magnon” to the discovered fossils. These individuals, which belong to the species Homo sapiens, are dated between 33 000 and 31 000 cal BP. As soon as these remains were discovered, researchers noticed a perforation in the frontal bone of the cranium of the individual named Cro-Magnon 2. Nevertheless, since this discovery, opinions differ as to the ante- or post-mortem nature of this perforation, i.e. whether the impact occurred before the death of the individual or whether it is the result of a degradation of the bone following its burial. Researchers have recently re-studied this cranium in order to evaluate the pathological or non-pathological character of this impact.

To do this, they made both visual observations but also generated scans and 3D images of the fossil using a micro X-ray tomograph. Cranial fractures that occurred before death have different characteristics that can be seen on the bones, such as the shape of the fracture or signs of healing. The study conducted here demonstrates that this perforation of the frontal bone is the result of an impact produced by a blunt object that occurred during the individual’s lifetime.
Traces of intracranial hemorrhage, the presence of a hematoma as well as porous bones indicate that the individual would have survived at least 15 days after this injury. It is impossible to affirm that this one was mortal but it is probable that this individual died of the consequences of this wound as for example of an infection. For the researchers, the position of the injury is consistent with the individual having been attacked and therefore not the result of an accident.

This raises the question of interpersonal violence during the Paleolithic, a question already raised with other fossil remains showing traces of injuries.

Read the full article here

Villalba-Mouco V., et al, “Kinship practices in the early state El Argar society from Bronze Age Iberia”, Scientific reports (2022) 12:22415, Nature, Published 27 December 2022.

Lien: https://www.nature.com/articles/s41598-022-25975-9

The Bronze Age in Europe was characterized by social and genetic transformations that began as early as the 3rd millennium BCE (Before Common Era). New funerary structures, political hierarchies and advances in metallurgy are emerging and playing an important role in the socio-economic mutations of these societies. New trade and exchange networks were set up. At the same time, paleogenetics revealed transformations in the ancestral gene pool that accompanied the profound socio-economic changes in the region. These transformations were linked to the expansion of pastoralist societies from Eastern Europe. The El Argar complex in the south of the Iberian Peninsula (Spain) bears witness to this genetic turnover in south-western Europe around 2200 BC. This article studies the genome of 68 individuals from the La Almoloya site. The results show that El Argar was a patrilineal society (type of filiation based on paternal descent) practicing exogamy (matrimonial rule imposing the search for a spouse outside one’s social group). The women who join El Argar reflect socio-political alliances.