Cueto, M. | bioRxiv Science

bioRxiv2023

A minimally-invasive method for ancient DNA sampling of Prehistoric bone and antler tools and hunting weapons

Internal and external bony tissues from diverse mammalian taxa are one of the primary animal raw materials exploited for technical and symbolic purposes by Eurasian Upper Palaeolithic hunter-gatherers. Identifying the source species used for osseous raw material is critical to gain insights into these populations behaviour, technology, and subsistence. The study of osseous tools has advanced in the last few years by combining archaeological and biomolecular methods. Ancient genomics opens many new analytical opportunities. Ancient DNA (aDNA) can provide a wealth of information about the animal sources of these objects. Unfortunately, aDNA analyses often involve destructive sampling. Here, we develop and apply a minimally-invasive aDNA sampling method for an assemblage of 42 prehistoric hunting weapons and tools from various Eurasian archaeological sites. We evaluated the impact of our approach on the specimens visually, microscopically and through Micro-CT scans. The surface impacts are marginal, ranging from 0.3-0.4 mm. Using a custom-made DNA capture kit for 54 mammalian species, we obtained sufficient aDNA to identify the taxa of 33% of the objects. For one of the tools, we recovered enough endogenous aDNA to infer the genetic affinities of the individual. Our results also demonstrate that ancient antler, one of the primary raw materials used during a large part of prehistory, is a reliable source of aDNA. Our minimally-invasive aDNA sampling method is therefore effective while preserving osseous objects for potential further analyses: morphometric, technical, genetic, radiometric and more.

genomics↗

bioRxiv2019

The Arrival of Steppe and Iranian Related Ancestry in the Islands of the Western Mediterranean

A series of studies have documented how Steppe pastoralist-related ancestry reached central Europe by at least 2500 BCE, while Iranian farmer-related ancestry was present in Aegean Europe by at least 1900 BCE. However, the spread of these ancestries into the western Mediterranean where they have contributed to many populations living today remains poorly understood. We generated genome-wide ancient DNA from the Balearic Islands, Sicily, and Sardinia, increasing the number of individuals with reported data from these islands from 3 to 52. We obtained data from the oldest skeleton excavated from the Balearic islands (dating to [~]2400 BCE), and show that this individual had substantial Steppe pastoralist-derived ancestry; however, later Balearic individuals had less Steppe heritage reflecting geographic heterogeneity or immigration from groups with more European first farmer-related ancestry. In Sicily, Steppe pastoralist ancestry arrived by [~]2200 BCE and likely came at least in part from Spain as it was associated with Iberian-specific Y chromosomes. In Sicily, Iranian-related ancestry also arrived by the Middle Bronze Age, thus revealing that this ancestry type, which was ubiquitous in the Aegean by this time, also spread further west prior to the classical period of Greek expansion. In Sardinia, we find no evidence of either eastern ancestry type in the Nuragic Bronze Age, but show that Iranian-related ancestry arrived by at least [~]300 BCE and Steppe ancestry arrived by [~]300 CE, joined at that time or later by North African ancestry. These results falsify the view that the people of Sardinia are isolated descendants of Europes first farmers. Instead, our results show that the islands admixture history since the Bronze Age is as complex as that in many other parts of Europe.

genomics↗