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.

We examine some long-standing assumptions about the early use of coastlines and marine resources and their contribution to the pattern of early human dispersal, and focus on the southern Red Sea basin and the proposed southern corridor of movement between Africa and Arabia across the Bab al-Mandab straits. We reconstruct relative sea levels in light of isostatic and tectonic effects, and evaluate their paleogeographical impact on the distribution of resources and human movement. We conclude that the crossing of the Bab al-Mandab posed little significant or long-lasting physical or climatic barrier to human transit during the Pleistocene and that the emerged continental shelf during periods of low sea level enhanced the possibilities for human settlement and dispersal around the coastlines of the Arabian Peninsula. We emphasise the paleogeographical and paleoenvironmental significance of Pleistocene sealevel change and its relationship with changes in paleoclimate, and identify the exploration of the submerged continental shelf as a high priority for future research. We conclude with a brief description of our strategy for underwater work in the Farasan Islands and our preliminary results.

The Mesolithic-to-Neolithic transition which coincided with rising sea levels, marked the time when a hunter-gatherer economy gave way to agriculture. Bouldnor Cliff is a submarine archaeological site with a well-preserved Mesolithic palaeosol dated to 8000 years BP. We analyze a core obtained from sealed sediments, combining evidence from microgeomorphology and microfossils with sedimentary ancient DNA (sedaDNA) analyses to reconstruct floral and faunal changes during occupation of this site, before it was submerged. In agreement with palynological analyses, the sedaDNA sequences suggest a mixed habitat of oak forest and herbaceous plants.However, in later sediments, they also provide evidence of wheat 2000 years earlier than expected. These results suggest that sophisticated social networks linked the Neolithic front in southern Europe to the Mesolithic peoples of northern Europe.The Mesolithic-to-Neolithic transition is associated with the replacement of a huntergatherer economy by arable farming of crops such as einkorn, emmer and barley.Although it is generally accepted that the Neolithic had arrived by 6000 years BP on the British mainland, controversy surrounds the timing and mode of Neolithisation in and MS-08 9 , Fig. S2). The sediment layers were of low porosity, with the palaeosol and peat layers sealed beneath dense, silty-clay marine alluvial sediments. We found a sharp boundary between the palaeosol and overlying peat, with no evidence of mixing of particles. Diatom and foraminifera analysis revealed a range of species in the superficial marine alluvial sediments. However, these did not penetrate into the underlying peat layer, indicating a lack of vertical movement in the sediment column.Given the absence of evidence of soil erosion (as might be revealed by illuviation or podsolization), we concluded that archaeological artefacts had been deposited in situ on a pristine land surface rather than entered the samples through alluvial deposition from another site. Radiocarbon dates obtained from 21 samples of wood and plant macrofossils from the sediment cores 9 (Table S1, Fig. S1, Fig. S2) allow an inference of marine inundation beginning 8020-7980 years cal BP, which represents the latest date for human activity at the site, with inundation complete by 7990-7900 years cal BP.We took four palaeosol sediment samples (S308 0-2cm, S308 2-4cm, S308 4-6cm and S308 6-8cm) from a location at the site associated with Mesolithic food debris (burnt hazelnut shells) 9 . The samples were taken at successive 2cm intervals from the top of the stratum, each roughly representing the period of a decade. Samples were taken on site 15 , examined for macrofossils and subjected to ancient DNA extraction in a dedicated laboratory 16 . Samples were found to be devoid of macrofossils, apart from a few Alnus glutinosa (common alder) twigs.We made Illumina libraries from the sediment cores and generated 71,856,199 256-bp single-end reads on the MiSeq platform (Table S2) (Table S3), were performed under high-strin...

The role of coastal regions and coastlines in the dispersal of human populations from Africa and across the globe has been highlighted by the recent polarisation between coastal and interior models. The debate has been clouded by the use of the single term 'coastal dispersal' to embrace what is in fact a wide spectrum of possibilities, ranging from seafaring populations who spend most of their time at sea living off marine resources, to land-based populations in coastal regions with little or no reliance on marine foods. An additional complicating factor is the fact of Pleistocene and early Holocene sea-level change, which exposed an extensive coastal region that is now submerged, and may have afforded very different conditions from the modern coastal environment. We examine these factors in the Arabian context and use the term 'Blue' to draw attention to the fertile coastal rim of the Arabian Peninsula, and to the now submerged offshore landscape, which is especially extensive in some regions. We further emphasise that the attractions of the coastal rim are a product of two quite different factors, ecological diversity and abundant water on land, which have created persistently 'Green' conditions throughout the vagaries of Pleistocene climate change in some coastal regions, especially along parts of the western Arabian escarpment, and potentially productive marine environments around its coastline, which include some of the most fertile in the world.We examine the interplay of these factors in the Southwest region of Saudi Arabia and the southern Red Sea, and summarise some of the results of recent DISPERSE field investigations, including survey for Palaeolithic sites on the mainland, and underwater survey of the continental shelf in the vicinity of the Farasan Islands.We conclude that coastlines are neither uniformly attractive nor uniformly marginal to human dispersal, that they offer diverse opportunities that were spatially and temporally variable at scales from the local to the continental, and that investigating Blue Arabia in relation to its episodically Green interior is a key factor in the fuller understanding of longterm human population dynamics within Arabia and their global implications.2