lab snippets

An Inca god’s colours revealed

By 18 janvier 2020 juillet 6th, 2020 No Comments

Hello LABNAUT readers,

This week we learn more about an Inca god’s colours, Corsican granite and the Roman Empire, and a new way to regulate the expression of RNA genes.

Researchers from the CNRSSorbonne UniversitéUniversité Paris 1 Panthéon-Sorbonne, the Muséum National d’Histoire Naturelle and the Musée du Quai Branly – Jacques Chirac have used X-ray fluorescence spectrometry to analyze the colours painted on a statue of the Inca god and oracle Pachacamac. This measurement, combined with the first carbon-14 dating of the statue, has shed light on how the Inca civilization and its predecessors used and valued coloured pigments.


Pachacamac Idol. In the last picture, the red arrows mark the presence of red pigments containing mercury.
© Marcela Sepulveda/Rommel Angeles/Museo de sitio Pachacamac

The researchers, reporting their work in PLOS ONE, say that the statue’s red pigment is not derived from blood, as was previously thought, but from a mercury-bearing ore called cinnabar. This result is unexpected since cinnabar is not usually found in the Andes, and the nearest source to the Pachacamac site is a few hundred kilometres away. Carbon-dating experiments have also revealed that the statue was fashioned around 731 AD, nearly 800 years before the Spanish conquest of the Inca Empire. This confirms that the Pachacamac site was already important for local people before the Incas adopted it as a centre of pilgrimage.

Meanwhile, a team of researchers from the Paris-Seine Institute of Biology (Sorbonne University/CNRS) has discovered two Drosophila genes whose products are capable of modifying RNAs. The results of their study, published in Nucleic Acids Research, characterize in detail the molecular and physiological defects observed during a loss of function of these genes in Drosophila. They could, in the future, make it possible to identify new determining biomarkers in the diagnosis of certain diseases.

Could Corsican granite have contributed to the wealth of the Roman Empire. Yes, say researchers led by Nadine Mattielli and Sébastien Clerbois, teams from the CReA-Patrimoine (Faculty of Philosophy and Social Sciences) and the G-Time Laboratory (Faculty of Sciences) of the Université libre de Bruxelles (ULB) who have now discovered that the various granite extraction sites on the island of Cavallo/San Bainzu (Lavezzi archipelago), Bonifacio, Corse-du-Sud), undoubtedly constitute one and the same quarry, with important dimensions, thus forming the largest quar.


The archeological site at Cavallo. Courtesy: CReA-patrimoine. The strait between Corsica and Sardinia was an important trade route in imperial times, particularly between present-day Spain and Rome.

The ULB project  is part of a Collective Research Programme (PCR) directed by Gaël Brkojewitsch (Metz Métropole, associate researcher, Aix-Marseille University, CNRS, CCJ, Aix-en-Provence). The study and the archaeological surveys have been authorised by the Ministry of Culture and the Prefecture of South Corsica and are partly financed by the Regional Directorate of Cultural Affairs of Corsica; the research is placed under the scientific control of the Regional Curator of Archaeology in Corsica, Mr Laurent Sévègnes. In Belgium, the programme is supported by the Fédération Wallonie-Bruxelles, the FNRS and the Université libre de Bruxelles.

For more information: Archéologie et Patrimoine en Corse