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Bones and teeth from archaeological records are direct evidence of past individuals and they represent valuable archives for palaeo-anthropological and palaeoenvironmental studies. However, pristine information may be obliterated by the diagenetic alteration of bone specimens. Thus, defining in detail their preservation state is fundamental to assess the potential of extracting information about the past life of the individual, as well as to investigate the palaeo-environment at the burial site. For this reason, we have selected a set of archaeological samples (petrous bones and tooth roots) of different origin and chronology that have experienced diverse environmental and burial conditions, from arid and semi-arid to temperate regions in a time span from prehistoric to fresh bones. Thus, the selected samples underwent a variety of diagenetic processes, resulting in different types and extent of alteration patterns. Here we have applied a minimally-invasive sampling strategy and an analytical protocol based on Fourier transform infrared spectroscopy (FTIR) in order to ensure the investigation of a statistically significant set of samples. We provide a method to describe and quantify the changes in the physico-chemical properties of both the organic and inorganic constituents of bones, by establishing a set of parameters calculated from the FTIR spectra and evaluating their sensitivity in describing the alteration types and extent in bone specimens. Through FTIR spectral analysis, we have defined the most suitable parameters to effectively describe the alteration degree of bone specimens. Notably, the results have shown that, despite the complexity of multifactorial diagenetic processes, their measurable effects on differently altered bones can be described by a common mechanism. This indicates a progressive loss of collagen which is paralleled to the recrystallization of bioapatite and the loss of structural carbonate, regardless of the origin and chronology of the specimens. Thus, here we propose an FTIR-based model for bone diagenesis of general validity, highlighting that distinct diagenetic processes affecting the archaeological bones have acted according to common alteration mechanisms. • Bone diagenetic alterations were analysed on a large and diversified set of samples. • An alternative and minimally destructive sampling method was applied for FTIR analysis. • Suitable FTIR parameters were defined to effectively describe the diagenetic alterations. • Diagenesis affects bones at different extent through common alteration mechanisms. • We propose an FTIR-based model for bone diagenesis of general validity. [ABSTRACT FROM AUTHOR]

Southern Italy was characterised by a complex prehistory that started with different Palaeolithic cultures, later followed by the Neolithization and the demic dispersal from the Pontic-Caspian Steppe during the Bronze Age. Archaeological and historical evidences point to a link between Southern Italians and the Balkans still present in modern times. To shed light on these dynamics, we analysed around 700 South Mediterranean genomes combined with informative ancient DNAs. Our findings revealed high affinities of South-Eastern Italians with modern Eastern Peloponnesians, and a closer affinity of ancient Greek genomes with those from specific regions of South Italy than modern Greek genomes. The higher similarity could be associated with a Bronze Age component ultimately originating from the Caucasus with high Iranian and Anatolian Neolithic ancestries. Furthermore, extremely differentiated allele frequencies among Northern and Southern Italy revealed putatively adapted SNPs in genes involved in alcohol metabolism, nevi features and immunological traits. • Complex interactions between the two sides of the Adriatic Sea unveiled from the genomes of present-day Southern Europeans • Uneven affinity between Neolithic Greeks and Southern Italians confirms the importance of post-Iron Age demographic events. • Shared Iran Neolithic-related ancestry suggests gene flows along the Mediterranean Sea shores that started in the Bronze Age. • Putatively adaptive signals in Northern and Southern Italians associated with alcohol metabolism and immunological traits. [ABSTRACT FROM AUTHOR]