The remarkable geographical situation of the Mediterranean region, located between Europe, Africa, and Asia, with numerous migratory routes, has made this area a crucible of cultures. Studying the Y-chromosome variability is a very performant tool to explore the genetic ancestry and evaluate scenarios that may explain the current Mediterranean gene pool. Here, six Mediterranean populations, including three Balearic Islands (Ibiza, Majorca, and Minorca) and three Southern Italian regions (Catanzaro, Cosenza, and Reggio di Calabria) were typed using 23 Y-STR loci and up to 39 Y-SNPs and compared to geographically targeted key reference populations to explore their genetic relationship and provide an overview of Y-chromosome variation across the Mediterranean basin. Pairwise RST genetic distances calculated with STRs markers and Y-haplogroups mirror the West to East geographic distribution of European and Asian Mediterranean populations, highlighting the North-South division of Italy, with a higher Eastern Mediterranean component in Southern Italian populations. In contrast, the African populations from the Southern coast of the Mediterranean clustered separately. Overall, these results support the notion that migrations from Magna Graecia or the Byzantine Empire, which followed similar Neolithic and post-Neolithic routes into Southern Italy, may have contributed to maintaining and/or reinforcing the Eastern Mediterranean genetic component in Southern Italian populations.

The Black Death had a devastating impact on communities living in Europe during the mid-14th century. The devastation wreaked by the epidemic was thought to lead to the disruption of social norms, including those surrounding the burial of the dead. Some scholars have, however, suggested this was not always the case, in particular for those communities living in rural settings (Kacki et al., 2011). Recent excavation at Thornton Abbey in Lincolnshire revealed two burial populations; one associated with the abbey's medieval hospital, and the other a mass grave that was in use during the Black Death epidemic. Together with the mass grave and post-epidemic burials from East Smithfield, London, these two populations presented an opportunity to explore the early taphonomic histories of the plague dead through the inspection of bone diagenesis associated with bacterial soft tissue decomposition. The histological analysis of 81 skeletons revealed striking differences in the post-mortem treatment of the plague dead in rural Lincolnshire compared to those buried in urban London, and in this paper we explore the possible scenarios that may account for this variability. We also present three cases where the individuals' status in life may have led to attempts at inhibiting their corporeal decay.

The identification of skeletal human remains, severely compromised by putrefaction, or highly deteriorated, is important for legal and humanitarian reasons. There are different tools that can help in the identification process such as anthropological and genetic studies. The success observed during the last decade in genetic analysis of skeletal remains has been possible especially due to the refinements of DNA extraction and posterior analysis techniques. However, despite these progresses, many challenges keep influencing the results of such analysis, mainly the limited amount and the degradation of the DNA recovered from badly preserved samples. By now, there is still no wide-range knowledge about post-mortem kinetics of DNA degradation. Therefore, taphonomy studies can play a key role in the reconstruction of post-mortem transformations that skeletal remains, and consequently DNA, have undergone. Thus, the goal of the present review focuses on the assessment of the literature regarding the possible effect of intrinsic (characteristics of the bone) and extrinsic (environmental) factors on the state of preservation of skeletal remains recovered in a terrestrial environment and their genetic material. The establishment of useful indicators describing the state of the remains is a key factor in order to determine their suitability for posterior biomolecular analysis.

The Y chromosome has been widely explored for the study of human migrations. Due to its paternal inheritance, the Y chromosome polymorphisms are helpful tools for understanding the geographical distribution of populations all over the world and for inferring their origin, which is really useful in forensics. The remarkable historical context of Europe, with numerous migrations and invasions, has turned this continent into a melting pot. For this reason, it is interesting to study the Y chromosome variability and how it has contributed to improving our knowledge of the distribution and development of European male genetic pool as it is today. The analysis of Y lineages in Europe shows the predominance of four haplogroups, R1b-M269, I1-M253, I2-M438 and R1a-M420. However, other haplogroups have been identified which, although less frequent, provide significant evidence about the paternal origin of the populations. In addition, the study of the Y chromosome in Europe is a valuable tool for revealing the genetic trace of the different European colonizations, mainly in several American countries, where the European ancestry is mostly detected by the presence of the R1b-M269 haplogroup. Therefore, the objective of this review is to compile the studies of the Y chromosome haplogroups in current European populations, in order to provide an outline of these haplogroups which facilitate their use in forensic studies.

In this study we report the application of a minisequencing panel of 52 SNPs of the mtDNA, which allows the determination of the major world-wide mitochondrial haplogroups, in highly degraded samples. A total of 25 human remains from a mass grave of the Spanish Civil War (1936–1939) were analyzed in order to define their corresponding mtDNA haplogroup and, subsequently, investigate possible maternal relationships with the available reference samples. The results highlight the potential of this 52 mtSNP panel as an efficient screening method that can be used as an alternative or complementary approach to mtDNA sequencing in order to discriminate among maternal lineages in highly degraded DNA samples.

In recent years, several studies have focused on species discrimination of bone fragments by histological analysis. According to literature, the most consistent distinguishing features are Haversian canal and Haversian system areas. Nonetheless, there is a consistent overlap between human and non-human secondary osteon dimensions. One of the features that have never been analyzed for the purpose of species discrimination is the osteocyte lacuna, a small oblong cavity in which the osteocyte is locked in. The aim of this study is to verify whether there are significant quantitative differences between human and pig lacunae within secondary osteons with similar areas. Study sample comprises the midshaft of long bones (humerus, radius, ulna, femur, tibia, and fibula) of a medieval human adult and a juvenile pig. Sixty-eight secondary osteons with similar areas have been selected for each species and a total of 1224 osteocyte lacunae have been measured. For each osteon, the total number of lacunae was counted, and the following measurements were taken: minimum and maximum diameter, area, perimeter, and circularity of nine lacunae divided between inner, intermediate, and outer lacunae. Statistical analysis showed minimal differences between human and pig in the number of lacunae per osteons and in the minimum diameter (P > 0.05). On the contrary, a significant difference (P < 0.001) has been observed in the maximum diameter, perimeter, area, and circularity. Although there is the need for further research on different species and larger sample, these results highlighted the potential for the use of osteocyte lacunae as an additional parameter for species discrimination. Concerning the difference between the dimensions of osteocyte lacunae based on their position within the osteon (inner, intermediate, and outer lacunae), results showed that their size decreases from the cement line towards the Haversian canal both in human and pig.

In this study, we present our experience in the genetic identification of skeletal remains recovered from graves of the Spanish Civil War (1936-1939) and posterior dictatorship (until 1970s). Up to now, we have carried out the genetic analysis of more than 500 human remains from graves located in the Spanish territory, particularly from the northern half. Autosomal STRs, Y-STRs, X-STRs and/or mtDNA were studied in order to establish kinship relationship with presumptive relatives and reach a successful identification of the unknown remains. In the last years, our efforts have focused on overcoming the limitations of this kind of analysis: limited quality and quantity of DNA recovered from the remains, partial genetic profiles from these samples and scarce number of appropriate family members for genetic comparisons. With this aim, we have optimized the process from the DNA extraction to the matching search, including an increased number of relatives' profiles in the genetic databases (n > 800), in order to raise the number of identifications.

At the end of 2016 and under the initiative and funding of the "Direccio General de Memoria democratica-Departament de Justicia" (Generalitat of Catalonia), it was decided to recover and identify the remains of people disappeared in Catalonia during and after the Spanish Civil War (1936-1939). Anthropology, archaeology, history and genetics are part of the global procedure. To achieve identification by genotyping, two different genetic approaches have been carried out 1) the directed identification through kinship analysis of alleged living relatives, when there is a previous evidence (archaeological, anthropological, historical) of a possible relationship (direct search); 2) the random crossing of a genetic profile database of victims and another database of alleged relatives in search of a possible identification (random search). The analyses of autosomal STRs, Y chromosome STRs and, in particular cases, X-InDels and mitochondrial DNA have been applied in both approaches. Here, we present the state of the process in Catalonian mass graves. Nowadays, a total of 102 post-mortem skeletal remains have been genotyped for autosomal STRs by Global Filer Express and Y-STRs from Yfiler Plus kit. Results were compared to nowadays data of living relatives in a database of 1519 genotyped for Global Filer kit, Yfiler Plus when paternally lineage was expected (248) and mitochondrial markers when maternally lineage was expected (111). Up to now, we have identified 5 victims: 4 were identified by direct strategy (including Y-STRs and mitochondrial DNA in 2 cases) and one by random search, without any previous evidence, suggesting that both strategies are useful in this context.

One of the fundamental questions in forensic medicine and anthropology is whether or not a bone or bone fragment is human. Surprisingly at times for the extreme degradation of the bone (charred, old), DNA cannot be successfully performed and one must turn to other methods. Histological analysis at times can be proposed. However, the variability of a single human skeleton has never been tested. Forty-nine thin sections of long, flat, irregular and short bones were obtained from a well-preserved medieval adult human skeleton. A qualitative histomorphological analysis was performed in order to assess the presence of primary and secondary bone and the presence, absence and orientation of vascular canals. No histological sections exhibited woven or fibro-lamellar bone. Long bones showed a higher variability with an alternation within the same section of areas characterized by tightly packed secondary osteons and areas with scattered secondary osteons immersed in a lamellar matrix. Flat and irregular bones appeared to be characterized by a greater uniformity with scattered osteons in abundant interstitial lamellae. Some cases of "osteon banding" and "drifting osteons" were observed. Although Haversian bone represent the most frequent pattern, a histomorphological variability between different bones of the same individual, in different portions of the same bone, and in different parts of the same section has been observed. Therefore, the present study has highlighted the importance of extending research to whole skeletons without focusing only on single bones, in order to have a better understanding of the histological variability of both human and non-human bone.