Ochre-based compound adhesives at the Mousterian type-site document complex cognition and high investment.

Ancient adhesives used in multicomponent tools may be among our best material evidences of cultural evolution and cognitive processes in early humans. African Homo sapiens is known to have made compound adhesives from naturally sticky substances and ochre, a technical behavior proposed to mark the advent of elaborate cognitive processes in our species. Foragers of the European Middle Paleolithic also used glues, but evidence of ochre-based compound adhesives is unknown. Here, we present evidence of this kind. Bitumen was mixed with high loads of goethite ochre to make compound adhesives at the type-site of the Mousterian, Le Moustier (France). Ochre loads were so high that they lowered the adhesive's performance in classical hafting situations where stone implements are glued to handles. However, when used as handheld grips on cutting or scraping tools, a behavior known from Neanderthals, high-ochre adhesives present a real benefit, improving their solidity and rigidity. Our findings help understand the implications of Pleistocene adhesive making.

Production method of the Königsaue birch tar documents cumulative culture in Neanderthals.

Birch tar is the oldest synthetic substance made by early humans. The earliest such artefacts are associated with Neanderthals. According to traditional interpretations, their study allows understanding Neanderthal tool behaviours, skills and cultural evolution. However, recent work has found that birch tar can also be produced with simple processes, or even result from fortuitous accidents. Even though these findings suggest that birch tar per se is not a proxy for cognition, they do not shed light on the process by which Neanderthals produced it, and, therefore, cannot evaluate the implications of that behaviour. Here, we address the question of how tar was made by Neanderthals. Through a comparative chemical analysis of the two exceptional birch tar pieces from Königsaue (Germany) and a large reference birch tar collection made with Stone Age techniques, we found that Neanderthals did not use the simplest method to make tar. Rather, they distilled tar in an intentionally created underground environment that restricted oxygen flow and remained invisible during the process. This degree of complexity is unlikely to have been invented spontaneously. Our results suggest that Neanderthals invented or developed this process based on previous simpler methods and constitute one of the clearest indicators of cumulative cultural evolution in the European Middle Palaeolithic. Supplementary information: The online version contains supplementary material available at 10.1007/s12520-023-01789-2.

Characterisation of hydrocarbon degradation, biosurfactant production, and biofilm formation in Serratia sp. Tan611: a new strain isolated from industrially contaminated environment in Algeria.

A novel bacterial strain was isolated from industrially contaminated waste water. In the presence of crude oil, this strain was shown to reduce the rate of total petroleum hydrocarbons (TPH) up to 97.10% in 24 h. This bacterium was subsequently identified by 16S rRNA gene sequence analysis and affiliated to the Serratia genus by the RDP classifier. Its genome was sequenced and annotated, and genes coding for catechol 1,2 dioxygenase and naphthalene 1,2-dioxygenase system involved in aromatic hydrocarbon catabolism, and LadA-type monooxygenases involved in alkane degradation, were identified. Gas Chromatography-Mass Spectrometry (GC-MS) analysis of crude oil after biological treatment showed that Serratia sp. Tan611 strain was able to degrade n-alkanes (from C13 to C25). This bacterium was also shown to produce a biosurfactant, the emulsification index (E24) reaching 43.47% and 65.22%, against vegetable and crude oil, respectively. Finally, the formation of a biofilm was increased in the presence of crude oil. These observations make Serratia sp. Tan611 a good candidate for hydrocarbon bioremediation.

Omics for Precious Rare Biosamples: Characterization of Ancient Human Hair by a Proteomic Approach.

Omics technologies have far-reaching applications beyond clinical medicine. A case in point is the analysis of ancient hair samples. Indeed, hair is an important biological indicator that has become a material of choice in archeometry to study the ancient civilizations and their environment. Current characterization of ancient hair is based on elemental and structural analyses, but only few studies have focused on the molecular aspects of ancient hair proteins-keratins-and their conservation state. In such cases, applied extraction protocols require large amounts of raw hair, from 30 to 100 mg. In the present study, we report an optimized new proteomic approach to accurately identify archeological hair proteins, and assess their preservation state, while using a minimum of raw material. Testing and adaptation of three protocols and of nano liquid chromatography-tandem mass spectrometry (nanoLC-MS/MS) parameters were performed on modern hair. On the basis of mass spectrometry data quality, and of the required initial sample amount, the most promising workflow was selected and applied to an ancient archeological sample, dated to about 3880 years before present. Finally, and importantly, we were able to identify 11 ancient hair proteins and to visualize the preservation state of mummy's hair from only 500 µg of raw material. The results presented here pave the way for new insights into the understanding of hair protein alteration processes such as those due to aging and ecological exposures. This work could enable omics scientists to apply a proteomic approach to precious and rare samples, not only in the context of archeometrical studies but also for future applications that would require the use of very small amounts of sample.

Archaeological resinous samples from Asian wrecks: Taxonomic characterization by GC-MS.

Plant resins, and particularly dammars from the Dipterocarpaceae family, were widely used in the past, notably as part of caulking material. The organic composition of resins, already complicated, is not always preserved over time and can be considerably affected by ageing. Hence, their occurrence in archaeological items leads to the necessity to identify them taxonomically with precision. Resinous organic materials collected near and/or on wrecks discovered in South China Sea, supposed to contain dammar resins because of their geographical excavation context, were investigated by gas chromatography-mass spectrometry (GC-MS), together with freshly collected dammars, to establish taxonomic and alteration parameters allowing to identify dammar even in very altered samples or in mixtures together with other organic materials. This study specially focuses on three samples collected within or close to the M1J wreck, a Portuguese wreck lost in the Straight of Malacca during the 16th century. Our analyses establish that all three are made of dammar, two of them in association with pitch and bitumen. In addition, biodegradation biomarkers were detected in all these three samples, indicating that they were submitted to microbial degradation processes during their ageing.