Karin Margarita Frei

Population genomics of Bronze Age Eurasia

The Bronze Age of Eurasia (around 3000–1000 BC) was a period of major cultural changes. However, there is debate about whether these changes resulted from the circulation of ideas or from human migrations, potentially also facilitating the spread of languages and certain phenotypic traits. We investigated this by using new, improved methods to sequence low-coverage genomes from 101 ancient humans from across Eurasia. We show that the Bronze Age was a highly dynamic period involving large-scale population migrations and replacements, responsible for shaping major parts of present-day demographic structure in both Europe and Asia. Our findings are consistent with the hypothesized spread of Indo-European languages during the Early Bronze Age. We also demonstrate that light skin pigmentation in Europeans was already present at high frequency in the Bronze Age, but not lactose tolerance, indicating a more recent onset of positive selection on lactose tolerance than previously thought.

Who was in Harold Bluetooth's army? Strontium isotope investigation of the cemetery at the Viking Age fortress at Trelleborg, Denmark

The circular fortress of Trelleborg on Zealand in Denmark is well known as a military camp with a key role in the formation of the Danish state under Harald Bluetooth in the tenth century AD. Taking a sample of 48 burials from the fort, strontium isotope analysis once again demonstrates its ability to eavesdrop on a community: at Trelleborg, the young men in its cemetery were largely recruited from outside Denmark, perhaps from Norway or the Slavic regions. Even persons buried together proved to have different origins, and the three females sampled were all from overseas, including a wealthy woman with a silver casket. Trelleborg, home of Harald Bluetooths army, was a fortress of foreigners with vivid implications for the nature of his political mission.

A multi-isotopic and trace element investigation of the Cretaceous–Tertiary boundary layer at Stevns Klint, Denmark – inferences for the origin and nature of siderophile and lithophile element geochemical anomalies

Os, Sr, Nd and Pb isotope data were collected from a profile across the Cretaceous–Tertiary (K–T) boundary layer at Stevns Klint, Denmark. ϵNd [T=65 Ma] values from within the boundary layer (Fish Clay) are lower by ∼1 ϵ unit than those of the underlying Maastrichtian limestone and the overlying Danian chalk sequences. Systematic profile-upward changes of Pb, Sr and Os isotopic compositions and concentrations in the boundary layer cannot be accounted for by in situ growth of daughter products since the sedimentation of the Fish Clay. While Os, Nd and Pb isotopes indicate the admixing of less radiogenic components to the Fish Clay, Sr isotopes show elevated radiogenic values in the boundary layer, relative to the carbonate sequences beneath and above it. The sudden change in lithophile (e.g., Sr, Pb and Nd) isotope compositions at the base of the Fish Clay and profile-upward trends of 87Sr/86Sr and 206Pb/204Pb ratios towards those of the overlying Danian chalk are interpreted to reflect recovery from enhanced, acid rain-induced continental (local?) weathering input to the seawater. However, a continental crustal source is invalid for the siderophile element Os. In the light of evidence from chromium isotopes for a cosmic origin of the platinum group elements (PGEs) and certain moderately siderophile elements (Cr, Ni, Co, V) in K–T boundary sediments, including Stevns Klint [Shukolyukov and Lugmair, Science 282 (1998) 927–929], and supported by the finding of projectile debris [Bauluz et al., Earth Planet. Sci. Lett. 182 (2000) 127–136] and the occurrence of abundant Ni-rich spinel at many K–T sites [Robin et al., Nature 363 (1993) 615–617; Kyte, Nature 396 (1998) 237–239], we favor to explain the sudden drop of 187Os/188Os ratios from 0.210 to 0.160 at the K–T boundary to derive from global fall-out of extraterrestrial matter. The present 186Os/188Os ratio of 0.119836±0.000004 measured in the basal layer of the Fish Clay is within the uncertainty a chondritic value. We therefore exclude the possibility of a major contribution of PGEs to the sediment from iron meteorites. Chondrite-normalized (Ru/Ir)N ratios of ∼0.95±0.14 and (Os/Ir)N ratios of ∼0.93±0.14 in the Fish Clay cannot distinguish between abundance ratios of different types of chondrites, and strongly sub-chondritic (Pt/Ir)N ratios of ∼0.62±0.09 (2σ) suggest differential PGE remobilization through the sedimentary column (and consequently the alteration of inter-element ratios). PGEs and the moderately siderophile elements Cr, Ni, V, and Co form an elemental association with systematically upward-decreasing concentrations in the Fish Clay. Low Co/Ni ratios of ∼0.12 in the Fish Clay relative to values of ∼0.35 in the over- and underlying carbonate sequences support mixing of meteorite-derived (Co/Ni ∼0.05) and terrestrial upper mantle/crustal (Co/Ni >∼0.3) sources. While lithophile element isotope data indicate an increased continental crustal input to the Fish Clay at the K–T transition, the uncertainty with respect to possible post-depositional alteration of abundance patterns of siderophile and moderately siderophile elements – though not affecting the chondritic isotopic composition of Os – does not allow confirmation of indications from chromium isotopes for a carbonaceous (CV-type) meteorite as the preferred K–T impactor type by Shukolyukov and Lugmair [Science 282 (1998) 927–929].

Strontium isotopes and human mobility in prehistoric Denmark

The principles behind the strontium isotopic system are an important tool for archaeologists tracing human migration and patterns of movement in prehistory. However, there are several scientific challenges of analytical nature, as well as those which relate to unknown parameters inherent to the interpretation of such data. One prerequisite is the knowledge of the range of strontium isotopic ratios that best characterize the bioavailable fractions of a particular area of interest. The study reported here attempts to establish a baseline for strontium isotope signatures valuable for Denmark (excluding the island of Bornholm) and particularly for the use in archaeological investigations. We present strontium isotope ratios of bones and teeth from modern mice contained in owl pellets, of snail shells, and of archaeological fauna samples. We compare these ratios with median strontium isotope signatures characterizing human enamel populations from archaeological sites within Denmark. The fauna samples reported here range from 87Sr/86Sr = 0.70717 to 0.71185 with an average of 0.70919, and human enamel defines a range from 87Sr/86Sr = 0.7086 to 0.7110 with an average of 0.7098. In both datasets, we observe a small difference between the baseline values for the western (Jutland) and eastern (Funen, Zealand, and the southern islands) parts of Denmark. We therefore propose two slightly different baseline ranges with a partial overlap for the isotopic signatures of bioavailable strontium fractions within Denmark, namely a range of 87Sr/86Sr = 0.7078–0.7098 for the western area and a range of 87Sr/86Sr = 0.7089–0.7108 for the eastern parts.

Re-theorising mobility and the formation of culture and language among the Corded Ware Culture in Europe

Abstract Recent genetic, isotopic and linguistic research has dramatically changed our understanding of how the Corded Ware Culture in Europe was formed. Here the authors explain it in terms of local adaptations and interactions between migrant Yamnaya people from the Pontic-Caspian steppe and indigenous North European Neolithic cultures. The original herding economy of the Yamnaya migrants gradually gave way to new practices of crop cultivation, which led to the adoption of new words for those crops. The result of this hybridisation process was the formation of a new material culture, the Corded Ware Culture, and of a new dialect, Proto-Germanic. Despite a degree of hostility between expanding Corded Ware groups and indigenous Neolithic groups, stable isotope data suggest that exogamy provided a mechanism facilitating their integration. This article should be read in conjunction with that by Heyd (2017, in this issue).

Tracing the dynamic life story of a Bronze Age Female.

Ancient human mobility at the individual level is conventionally studied by the diverse application of suitable techniques (e.g. aDNA, radiogenic strontium isotopes, as well as oxygen and lead isotopes) to either hard and/or soft tissues. However, the limited preservation of coexisting hard and soft human tissues hampers the possibilities of investigating high-resolution diachronic mobility periods in the life of a single individual. Here, we present the results of a multidisciplinary study of an exceptionally well preserved circa 3.400-year old Danish Bronze Age female find, known as the Egtved Girl. We applied biomolecular, biochemical and geochemical analyses to reconstruct her mobility and diet. We demonstrate that she originated from a place outside present day Denmark (the island of Bornholm excluded), and that she travelled back and forth over large distances during the final months of her life, while consuming a terrestrial diet with intervals of reduced protein intake. We also provide evidence that all her garments were made of non-locally produced wool. Our study advocates the huge potential of combining biomolecular and biogeochemical provenance tracer analyses to hard and soft tissues of a single ancient individual for the reconstruction of high-resolution human mobility.

Strontium Isotope Signals in Cremated Petrous Portions as Indicator for Childhood Origin

Dental enamel is currently of high informative value in studies concerning childhood origin and human mobility because the strontium isotope ratio in human dental enamel is indicative of geographical origin. However, many prehistoric burials involve cremation and although strontium retains its original biological isotopic composition, even when exposed to very high temperatures, intact dental enamel is rarely preserved in cremated or burned human remains. When preserved, fragments of dental enamel may be difficult to recognize and identify. Finding a substitute material for strontium isotope analysis of burned human remains, reflecting childhood values, is hence of high priority. This is the first study comparing strontium isotope ratios from cremated and non-cremated petrous portions with enamel as indicator for childhood origin. We show how strontium isotope ratios in the otic capsule of the petrous portion of the inner ear are highly correlated with strontium isotope ratios in dental enamel from the same individual, whether inhumed or cremated. This implies that strontium isotope ratios in the petrous bone, which practically always survives cremation, are indicative of childhood origin for human skeletal remains. Hence, the petrous bone is ideal as a substitute material for strontium isotope analysis of burned human remains.

Nettle as a distinct Bronze Age textile plant

It is generally assumed that the production of plant fibre textiles in ancient Europe, especially woven textiles for clothing, was closely linked to the development of agriculture through the use of cultivated textile plants (flax, hemp). Here we present a new investigation of the 2800 year old Lusehøj Bronze Age Textile from Voldtofte, Denmark, which challenges this assumption. We show that the textile is made of imported nettle, most probably from the Kärnten-Steiermark region, an area which at the time had an otherwise established flax production. Our results thus suggest that the production of woven plant fibre textiles in Bronze Age Europe was based not only on cultivated textile plants but also on the targeted exploitation of wild plants. The Lusehøj find points to a hitherto unrecognized role of nettle as an important textile plant and suggests the need for a re-evaluation of textile production resource management in prehistoric Europe.

Old Textiles – New Possibilities

AbstractTextile research has become an important field of archaeology. Although the established analytical methods are often viewed as specialized, their integration with other interdisciplinary approaches allows us to deal with broader archaeological issues and provides the interpretational base for a much more comprehensive investigation of textiles in ancient times. Analyses of fibres, Together, these approaches can provide new knowledge about textile production and consumption and, thereby, about people and society in ancient times. dyes, archaeobotanical and archaeozoological remains, as well as palaeoenvironmental and geochemical investigations, provide information about available resources, while tool studies, experimental testing, and visual grouping are approaches that explore the technology and techniques.

Was it for walrus? Viking Age settlement and medieval walrus ivory trade in Iceland and Greenland

Abstract Walrus-tusk ivory and walrus-hide rope were highly desired goods in Viking Age north-west Europe. New finds of walrus bone and ivory in early Viking Age contexts in Iceland are concentrated in the south-west, and suggest extensive exploitation of nearby walrus for meat, hide and ivory during the first century of settlement. In Greenland, archaeofauna suggest a very different specialized long-distance hunting of the much larger walrus populations in the Disko Bay area that brought mainly ivory to the settlement areas and eventually to European markets. New lead isotopic analysis of archaeological walrus ivory and bone from Greenland and Iceland offers a tool for identifying possible source regions of walrus ivory during the early Middle Ages. This opens possibilities for assessing the development and relative importance of hunting grounds from the point of view of exported products.