Awareness of forensic anthropology in Switzerland: a survey among forensic practitioners, police, and prosecutors.

Forensic anthropology (FA) as a specialized discipline has been practised in multi-lingual Switzerland for over a decade. A variety of expertise regarding osteological assessments as well as facial image comparison (FIC) is provided by different centres. Nevertheless, information is lacking about the awareness of FA and its benefits for forensic investigations among forensic stakeholders. Therefore, a survey was sent to Swiss anthropologists (AN) and related professions (police officers, prosecutors, and forensic pathologists) to assess three main aspects: (1) the experience of working (biological/forensic) anthropologists within FA; (2) how FA is perceived by other professions within the legal system; and (3) identify gaps (if any) in understanding of FA with the aim to suggest avenues for improvement if necessary. The results show that awareness of FA varies by occupation and cantonal regions. In areas where close collaborations between forensic anthropologists (FAs) and other stakeholders have been formally established, be it with focus on osteological analyses or FIC, the awareness of FA competencies was superior to areas where this was not the case. An overwhelming majority of forensic actors expressed interest in continuing education related to the role of FA. These findings indicate that facilitation of communication and collaboration leads to improvement in the awareness of the competencies of FAs and their contribution to forensic investigations.

Author Correction: Ancient genomes reveal social and genetic structure of Late Neolithic Switzerland.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Ancient genomes reveal social and genetic structure of Late Neolithic Switzerland.

Genetic studies of Neolithic and Bronze Age skeletons from Europe have provided evidence for strong population genetic changes at the beginning and the end of the Neolithic period. To further understand the implications of these in Southern Central Europe, we analyze 96 ancient genomes from Switzerland, Southern Germany, and the Alsace region in France, covering the Middle/Late Neolithic to Early Bronze Age. Similar to previously described genetic changes in other parts of Europe from the early 3rd millennium BCE, we detect an arrival of ancestry related to Late Neolithic pastoralists from the Pontic-Caspian steppe in Switzerland as early as 2860-2460 calBCE. Our analyses suggest that this genetic turnover was a complex process lasting almost 1000 years and involved highly genetically structured populations in this region.

Emergence of human-adapted Salmonella enterica is linked to the Neolithization process.

It has been hypothesized that the Neolithic transition towards an agricultural and pastoralist economy facilitated the emergence of human-adapted pathogens. Here, we recovered eight Salmonella enterica subsp. enterica genomes from human skeletons of transitional foragers, pastoralists and agropastoralists in western Eurasia that were up to 6,500 yr old. Despite the high genetic diversity of S. enterica, all ancient bacterial genomes clustered in a single previously uncharacterized branch that contains S. enterica adapted to multiple mammalian species. All ancient bacterial genomes from prehistoric (agro-)pastoralists fall within a part of this branch that also includes the human-specific S. enterica Paratyphi C, illustrating the evolution of a human pathogen over a period of 5,000 yr. Bacterial genomic comparisons suggest that the earlier ancient strains were not host specific, differed in pathogenic potential and experienced convergent pseudogenization that accompanied their downstream host adaptation. These observations support the concept that the emergence of human-adapted S. enterica is linked to human cultural transformations.

Those who died very young-Inferences from δ15 N and δ13 C in bone collagen and the absence of a neonatal line in enamel related to the possible onset of breastfeeding.

OBJECTIVES: Stable isotope analysis has often been used in neonatal remains from archeological contexts to investigate the presence of a signal of breastfeeding and weaning in past populations. Tooth histology on the other hand might be used as an indicator of birth survival. This pilot study aimed to investigate the feasibility of using stable nitrogen (δ15 N) and carbon (δ13 C) isotope values from neonatal bone collagen to elucidate if values deviating from the adult female average could indicate breastfeeding and co-occur with the presence of a neonatal line (NNL). The combination of these independent indicators might be useful in clarifying the fate of individuals who died around birth. MATERIALS AND METHODS: Bone collagen from 21 archeological human and animal specimens was extracted and analyzed via mass-spectrometry for δ15 N and δ13 C. A verification of the stable isotope results was undertaken using tooth histology on three individuals who were investigated for the presence of a NNL as an indicator of live birth and short survival. RESULTS: The biological age of the human samples varied between 8.5 lunar months (Lm) and 2 postnatal months (Pm) of age. All except one individual exhibited elevated δ15 N values compared to the female average. The histological analyses revealed no NNL for this and two further individuals (n = 3). DISCUSSION: The results indicate that elevated nitrogen values of very young infants relative to a female average in archeological contexts are not necessarily associated with a breastfeeding onset signal, and therefore cannot be used exclusively as a proxy of birth survival. The elevation might be possible due to various reasons; one could be nutritional, in particular maternal stress during pregnancy or a metabolic disorder of mother and/or her child. In those cases, the evaluation of a NNL might reveal a false breastfeeding signal as seen for two individuals in our sample who have elevated nitrogen values despite the fact no NNL could be observed. Overall, our data support the growing awareness that bone collagen δ15 N values of neonates/infants should not be used as a proxy for breastfeeding or birth survival on its own.

Ratio of mitochondrial to nuclear DNA affects contamination estimates in ancient DNA analysis.

In the last decade, ancient DNA research has grown rapidly and started to overcome several of its earlier limitations through Next-Generation-Sequencing (NGS). Among other advances, NGS allows direct estimation of sample contamination from modern DNA sources. First NGS-based approaches of estimating contamination measured heterozygosity. These measurements, however, could only be performed on haploid genomic regions, i.e. the mitochondrial genome or male X chromosomes, but provided no measures of contamination in the nuclear genome of females with their two X chromosomes. Instead, female nuclear contamination is routinely extrapolated from mitochondrial contamination estimates, but it remains unclear if this extrapolation is reliable and to what degree variation in mitochondrial to nuclear DNA ratios affects this extrapolation. We therefore analyzed ancient DNA from 317 samples of different skeletal elements from multiple sites, spanning a temporal range from 7,000 BP to 386 AD. We found that the mitochondrial to nuclear DNA (mt/nc) ratio negatively correlates with an increase in endogenous DNA content and strongly influenced mitochondrial and nuclear contamination estimates in males. The ratio of mt to nc contamination estimates remained stable for overall mt/nc ratios below 200, as found particularly often in petrous bones but less in other skeletal elements and became more variable above that ratio.