Matrilineal diversity and population history of Norwegians

Background While well known for its Viking past, Norway's population history and the influences that have shaped its genetic diversity are less well understood. This is particularly true with respect to its demography, migration patterns, and dialectal regions, despite there being curated historical records for the past several centuries. In this study, we undertook an analysis of mitochondrial DNA (mtDNA) diversity within the country to elaborate this history from a matrilineal genetic perspective. Methods We aggregated 1174 partial modern Norwegian mtDNA sequences from the published literature and subjected them to detailed statistical and phylogenetic analysis by dialectal regions and localities. We further contextualized the matrilineal ancestry of modern Norwegians with data from Mesolithic, Iron Age, and historic period populations. Results Modern Norwegian mtDNAs fell into eight West Eurasian (N, HV, JT, I, U, K, X, W), five East Eurasian (A, F, G, N11, Z), and one African (L2) haplogroups. Pairwise analysis of molecular variance (AMOVA) estimates for all Norwegians indicated they were differentiated from each other at 1.68% (p < 0.001). Norwegians within the same dialectal region also showed genetic similarities to each other, although differences between subpopulations within dialectal regions were also observed. In addition, certain mtDNA lineages in modern Norwegians were also found among prehistoric and historic period populations, suggesting some level of genetic continuity over hundreds to many thousands of years. Conclusions This analysis of mtDNA diversity provides a detailed picture of the genetic variation within Norway in light of its topography, settlement history, and historical migrations over the past several centuries.publishedVersio

A new time: Bayesian models of an Early Neolithic enclosure in North-Western Denmark

The article presents the results of the first Bayesian model of a causewayed enclosure from Denmark. 21 samples were dated, some with multiple dates, giving a total of 41 dates. These dates are built into a model which includes archaeological priors in the form of stratigraphy. It is demonstrated that this enclosure can be dated to the same time as the majority of enclosures on the British Isles: the 37th century BC. Together with other early dates for enclosures, it illustrates that enclosure construction was introduced in South Scandinavia as part of a large European expansion of enclosures. With Bayesian modelling, we can provide better answers to more questions, both regarding intrasite chronologies and a wide range of chronological issues

Post-glacial colonization of Western Europe brown bears from a cryptic Atlantic refugium out of the Iberian Peninsula

This is an Accepted Manuscript version, accepted for publication in Historical Biology.[Abstract] The European brown bear (Ursus arctos) shows a particular phylogeography that has been used to illustrate the model for contraction-expansion dynamics related to glacial refugia in Southern European peninsulas. Recent studies, however, have nuanced the once generally accepted paradigm, indicating the existence of cryptic refugia for some species further north. In this paper we collected available data on chronology and mitochondrial haplotypes from Western European brown bears, adding new sequences from present day individuals from the Cantabrian (North Iberia) area, in order to reconstruct the dynamics of the species in the region. Both genetics and chronology show that the Iberian Pleistocene lineages were not the direct ancestors of the Holocene ones, the latter entering the Peninsula belatedly (around 10,000 years BP) with respect to other areas such as the British Isles. We therefore propose the existence of a cryptic refugium in continental Atlantic Europe, from where the bears would expand as the ice receded. The delay in the recolonization of the Iberian Peninsula could be due to the orographic characteristics of the Pyrenean-Cantabrian region and to the abundant presence of humans in the natural entrance to the Peninsula.This work is part of the BIOGEOS [grant number CGL2014-57209-P] Research Project of the Spanish Ministry of Economy (MINECO/FEDER) and Competitiveness and a Consolidating grant from the Xunta de Galicia for emerging research groups [grant number GPC2015/024]Xunta de Galicia; GPC2015/02