Large-scale migration into Britain during the Middle to Late Bronze Age

Abstract

The cemetery is located in the south-west of Pottenbrunn, on plot "Steinfeld" (15°41´05"/48°13´55"). Discovered in 1930, it had already yielded objects dating to the early La Tène period. In 1981, road construction revealed further finds which initiated rescue excavations by the Bundesdenkmalamt (State Office for Protection of Historical Monuments) under the guidance of J.-W. Neugebauer (Ramsl 2002a(Ramsl , 13) in 1981(Ramsl and 1982. A total of 42 graves with 45 burials (single and double inhumations, and cremations) have been documented. Some burials were severely disturbed (by ancient activities such as grave robbing and/or contemporary construction work), and some were set within fenced enclosures ("Grabgärten"). Three (of 22) samples of charcoal and bone fragments taken by Peter Stadler (Department of Prehistory, Natural History Museum Vienna) in the course of the FWFproject "Absolute Chronology for Early Civilisations in Austria and Central Europe" returned AMS dates of 410-200 cal BCE (grave 520), 550-200 cal BCE (grave 565) and 380-350 cal BCE (grave 1005) (Ramsl 2002b, 359). The cremation burials were not included in the initial osteological analysis, but 31 inhumed individuals were studied (Gerold 2002). Petrous bones from three of these were successfully analyzed for aDNA. Sample I11699 (female) derived from an individual (inv. no. 26.238) aged c. 20 years in grave 89 which, despite disturbance in antiquity, was accompanied by fibulae and ceramic vessels. Sample I11701 (male) derived from an individual (inv. no. 26.249) aged c. 18 years in grave 570, which also included shears, fibulae, and ceramic vessels. Evidence for bone porosity in the mandible and maxilla suggest possible Vitamin C deficiency, while enamel hypoplasia points to malnutrition or illness during childhood. Sample I11708 (female) derived from an individual (inv.no. 26.250) aged c. 25-35 years in grave 574/2, who was richly adorned with fibulae, bronze, iron and silver-rings, an amber ring, a bracelet, a glass bead, and a worked bone artefact.

Direct detection of natural selection in Bronze Age Britain

“…The main limitation of our approach is the assumption of population continuity. Although there is evidence of external migration into Britain during the time period we investigated [8], there is relatively little change in genetic ancestry since the sources of that migration are genetically similar populations from other nearby parts of Northern Europe. If this affects our results it would likely mean that some of the selection we detected actually occurred in those neighboring populations, somewhat earlier than the dates we find here.…”

“…We collected data from ancient British individuals dated to the past 4500 years from the Allen Ancient DNA resource (v44.3, [27], original sources [28, 29, 30, 31, 7]) and Patterson et al (2022) [8]. Most samples had been genotypyed on the 1240k array, and the small number of shotgun samples had been genotyped at the 1240k SNPs so we therefore restricted our analysis to this set of SNPs.…”

“…Ancient genotype data was from the Allen Ancient DNA Resource v4.3 [27] (original sources cited in main text), and Patterson et al 2022 [8]. Present-day data from the 1000 Genomes Project [32] was reprocessed as described in the AADR.…”

“…With the recent publication of large aDNA datasets [e.g., 8, 9, 7], sample sizes for some regions are now in the hundreds of individuals, large enough to study selection with good spatial and temporal resolution. However, there is a lack of suitable methods to analyze these data.…”

Three Reagents for in-Solution Enrichment of Ancient Human DNA at More than a Million SNPs

“…To do this we mine data from 488 libraries for which we had shotgun data at a median of 5-fold coverage and also good 1240k data (much of this dataset is available as a pre-publication data release at https://reich.hms.harvard.edu/ancient-genome-diversity-project). We used imputation with GLIMPSE (42) to infer diploid genotypes at each SNP location (43) and counted rates of sequences matching to the reference and variant allele in all individuals where the posterior probability of being heterozygous was >0.9 at a given SNP. If there are no biases in enrichment, the frequency of observing the reference allele in the 1240k enrichment data is expected to match that in the shotgun sequence data (both 0.5).…”