The exploration and reconstruction of the interaction between humans, their domestic animals and their sociocultural influences have a long research history. The focus of this work is the domestication and the keeping of the pig (Sus scrofa) in Northern Europe during the Neolithic and early medieval times. This study applied approaches from the humanities and natural sciences to generate a multiplicity of data over different environmental conditions, which offered the possibility to clarify the biological compositions of the examined pig populations and the life strategies and living conditions of past societies. In this study, 348 domestic pigs and 104 wild boars from Mesolithic/Neolithic and early medieval sites were examined. Several fragments of the mitochondrial genome (mtDNA) were analyzed and compared with already existing data from databases and a reference collection of 64 modern wild boars and domestic pigs. It was possible to amplify mtDNA for 44 % of the Neolithic/Mesolithic and for 70 % of the early medieval samples. Furthermore, an analysis method utilizing SNPs associated with phenotype was developed and applied for a reliable estimation of the coat color from the smallest quantities of DNA.

It was possible to differentiate the Mesolithic/Neolithic pig populations by time and space, within the analysis of one D-loop-fragment and four cytochrome b (cytb)-fragments of the mtDNA. Four haplogroups could be identified in the results, the European haplogroups (represent by the haplotypes ANC-A and ANC-C) is found in 80% of the domestic pigs and the Near Eastern haplogroups (represent by the haplotypes ANC-Y1-6A and ANC-Y2-5A) in 20% of the domestic pigs. The wild boar populations in Europe are posed the European haplogroups ANC-A and ANC-C. Thus the domestic pigs with the haplotypes ANC-Y1-6A and -Y2-5A in the Neolithic period shows a maternal lineage from the Near East. This indicates that the domestic pigs were introduced into Europe in a similar way as other animals such as cattle, goats and sheep from the Near East. The observed genetic data supports the scenario that the Neolithic transition could be explained by the “leap frog colonization“- model. Higher haplotype diversity was observed in the examined ancient samples than in modern wild and domestic pig populations. The genetic selection of domestic pigs through breeding could have led to a fast disappearance of the haplotypes from the Near East. The strong reduction of the diversity within the wild boars could be due to direct and indirect factors, e.g. the loss of habitat or poor adaptation to the climate and the landscapes of Northern Europe.

It was not possible to differentiate domestic and wild pigs based on the mtDNAdata. Combining the genetic data with the archaeological context allowed some distinction between the two animals. Due to the fact that only the domestic pigs carried the haplotypes ANC-Y1-6A and ANC-Y2-5A in Europe, all European pigs assigned to a haplogroup from the Near East can be considered domestic. The analysis of the MC1R gene shows a clear differentiation between wild and domestic pigs according to coat color. The genotype of three domestic pigs and a wild boar were determined; all of them are reflecting black-spotted phenotypes, which differ from the wild type.

For the first time, the haplotype of three wild pigs from settlements of the Ertebølle culture could be assigned to ANC-Y1. Three possible explanations for this finding are possible. First, the archaeozoological determination of the domestication-status is not sensitive enough and thus domestic pigs have been determined as wild. This is supported by the coat color and isotope analyses of one sample (WG 24). This hypothesis would suggest a direct exchange between the Ertebølle and the LBK culture. Second, feral pigs from LBK settlements have immigrated as wild boars into Ertebølle settlements. Third, this may reflect local wild animals with the haplotype ANC-Y1, which spread until the last ice age into Northern Europe. The result schows that the Near East haplotypes could be regarded as local and European. Furthermore, this can be interpreted as an “idea transfer” and/or an autochthonous domestication of the pigs in Northern Germany.

Samples from the early medieval sites are genetically very homogeneous, which shows a long tradition of breeding and thereby continuous genetic selection. The genetic results did not show an association with the different cultural groups such as Friesian, Saxony, Slavonic and Danish. The results of the MC1R gene corroborate this. The animals showed the allele 501/501, which is the phenotype EP described as black-spotted, and differs from the wild type. The collection of a multiplicity of genetic information in the context of this work contributes to the clarification of the pig phylogeny. Beyond that, the results contribute to the contextualization and reconstruction of the subsistence strategy of the Neolithic of Northern Europe and the early medieval period of Northern Germany.