High-Throughput DNA sequencing of ancient wood.

Reconstructing the colonization and demographic dynamics that gave rise to extant forests is essential to forecasts of forest responses to environmental changes. Classical approaches to map how population of trees changed through space and time largely rely on pollen distribution patterns, with only a limited number of studies exploiting DNA molecules preserved in wooden tree archaeological and subfossil remains. Here, we advance such analyses by applying high-throughput (HTS) DNA sequencing to wood archaeological and subfossil material for the first time, using a comprehensive sample of 167 European white oak waterlogged remains spanning a large temporal (from 550 to 9,800 years) and geographical range across Europe. The successful characterization of the endogenous DNA and exogenous microbial DNA of 140 (~83%) samples helped the identification of environmental conditions favouring long-term DNA preservation in wood remains, and started to unveil the first trends in the DNA decay process in wood material. Additionally, the maternally inherited chloroplast haplotypes of 21 samples from three periods of forest human-induced use (Neolithic, Bronze Age and Middle Ages) were found to be consistent with those of modern populations growing in the same geographic areas. Our work paves the way for further studies aiming at using ancient DNA preserved in wood to reconstruct the micro-evolutionary response of trees to climate change and human forest management.

Creating frames of reference for chert exploitation during the Late Pleistocene in Southwesternmost Iberia.

Southwestern Iberia has played a key role in characterizing Late Pleistocene human ecodynamics. Among other aspects of human behavior, chert procurement and management studies in this region have received increasing attention in the past two decades, especially focusing on the sites showing repeated human occupation, such as the case of Vale Boi (Southern Portugal). However, these studies have been very limited in their geographical scope, and mostly focused on brief macroscopic descriptions of the raw materials. To further our knowledge of the relationship between regional availability of raw materials and its impact on human adaptations and mobility, a more detailed approach to characterizing geological sources is needed. This paper characterizes chert raw materials location, diversity, and availability in a geologically well-defined region of southern Portugal - the Algarve. Through macroscopic and petrographic approaches, we provide a detailed characterization of geological chert sources to build a frame of reference for chert exploitation in the region. Our results show that there are four main chert formations in Algarve, and that despite the within-source variability, sufficient differences at macroscopic and petrographic levels are present to allow clear source attribution. These results provide a baseline for raw material studies in archaeological assemblages across southwestern Iberia, that will be essential to further characterize the dynamics of human behavior in some of the most important eco-cultural niches.

The status of imported Barremian-Bedoulian flint in north-eastern Iberia during the Middle Neolithic. Insights from the variscite mines of Gavà (Barcelona).

Barremian-Bedoulian flint from the Vaucluse region (western Provence, SE France), is traditionally considered one of the most significant chrono-cultural markers of the Chasséen culture during the Middle Neolithic (end of the 5th and beginning of the 4th millennium BC). Diffusion of Provençal flints became massive during the first half of the 4th millennium BC, penetrating in several neighbouring cultural spheres such as the Sepulcros de Fosa culture in north-eastern Iberia. The integrated study of the lithic assemblages from the variscite mines of Gavà (Barcelona) and its contextualization within the Sepulcros de Fosa culture in north-eastern Iberia have revealed unexpected complexity in the modes of consumption, use and status of imported Barremian-Bedoulian industries in north-eastern Iberia during the 5th to 4th millennia cal. BC transition. Local communities within this region, already controlling extraction and regional diffusion of variscite ornaments, exerted control over the fluxes of Vauclusian flint south of the Pyrenees, where it had a triple status (functional, symbolic and both). In addition, the results provide complementary data to better understand relevant aspects of the nature and organisation of Barremian-Bedoulian flint exploitation and early supply systems at the Provençal producing sites during the later phase of the Chasséen culture.

Punk's not dead. Fungi for tinder at the Neolithic site of La Draga (NE Iberia).

This paper presents the study of the fungi remains preserved in the waterlogged deposits of the Neolithic site of La Draga. These resources had the potential of being used as food and medicine, but also as tinder. Fire was without a doubt one of the most important resources for past people. It was used for lighting, heating, processing food and other materials, cooking and protection, and also possessed social and ritual significance. Hearths are one of the most common features at archaeological sites, but very often little attention is paid to the question of how these fires were lit, and they are seldom reflected in the archaeological record. In order to produce fire by percussion, an intermediate material is required between the sparks and the fuel. Fruiting bodies of fungi are a potential form of tinder, but are less inclined to be well-preserved than other materials. This paper presents the fungal fruiting bodies found at the Neolithic site of La Draga and discusses the meaning of their presence within the archaeological context of the site and European Prehistory.

The emergence of mesolithic cemeteries in SW Europe: insights from the El Collado (Oliva, Valencia, Spain) radiocarbon record.

Located on the Iberian Mediterranean coast, El Collado is an open-air site where a rescue excavation was conducted over two seasons in 1987 and 1988. The archaeological work excavated a surface area of 143 m2 where 14 burials were discovered, providing skeletal remains from 15 individuals. We have obtained AMS dates for 10 of the 15 individuals by means of the direct dating of human bones. The ranges of the probability distribution of the calibrated dates suggest that the cemetery was used during a long period of time (781-1020 years at a probability of 95.4%). The new dates consequently set back the chrono-cultural attribution of the cemetery from the initial proposal of Late Mesolithic to an older date in the Early Mesolithic. Therefore, El Collado becomes the oldest known cemetery in the Iberian Peninsula, earlier than the numerous Mesolithic funerary contexts documented on the Atlantic façade such as the Portuguese shell-middens in the Muge and Sado Estuaries or the funerary sites on the northern Iberian coast.