With the help of ancient DNA analysis, Graduate School members Ben Krause-Kyora and Almut Nebel provide evidence for intercultural contact during the Stone Age in Northern Germany. The results of their research team have been published in Nature Communications.

Wild boar in Kiel’s Projensdorf grove. Its ancestors have been living by the Baltic Sea for ages.

While some inhabitants still hunted seals and wild boar on the Western Baltic coast, other inhabitants south of the Elbe River already implemented crop cultivation and animal husbandry. During the 5th century BC, the river represented a border between Mesolithic and Neolithic cultures. At the same time, neighboring groups with large developmental differences also existed in many other regions of Europe. Thus, it has been questioned for many decades within archaeology, cultural studies and related fields, whether the members of the quite different cultures held direct contact with each another. A research group led by Dr. Ben Krause-Kyora and Professor Almut Nebel of Kiel University has now provided clear evidence that hunters and farmers were not only acquainted with each other but even traded live animals. In the scientific journal Nature Communications (online) they report that members of the Mesolithic Ertebølle culture already held domestic pigs as early as 4600 BC, although they were – as hunters and gatherers – not yet familiar with animal husbandry. Krause-Kyora concluded that they most likely obtained the animals from the members of the more developed Neolithic cultures south of the Elbe River, who were already agriculturally active. “Thus, we can show for northern regions that direct contact existed between hunters and gatherers, on the one hand, and farmers on the other hand”, mentioned Krause-Kyora with satisfaction. The new results are also meaningful from an evolutionary perspective: “They provide us with important information on how domesticated animals spread to Northern Germany and how the early phases of domestication proceeded”.

Ben Krause-Kyora pulls out a tooth from the lower jaw of a pig to extract ancient DNA from it.

The Kiel research team investigated the ancient DNA (aDNA) from the bones and teeth of a total of 63 pigs, which were discovered at archaeological excavations in Northern and Central Germany. The molecular genetic analyses were carried out in the aDNA laboratory of the Graduate School Human Development in Landscapes. The analysis of the mitochondrial DNA, which is exclusively inherited along the maternal line, revealed that three animals from former Ertebølle settlements in Grube-Rosenhof (Eastern Holstein) and Poel (Mecklenburg-Western Pomerania) exhibit a genetic profile that originated in the Middle East, which was not present among wild Northern European counterparts. This finding shows that the three Ertebølle animals had maternal ancestors from the Middle East – similar to the domestic pigs of Neolithic neighbors. Domestic pigs had spread in previous centuries to the region south of the Elbe River due to the expansion of farmers and animal breeders from the so-called Fertile Crescent (today Syria, Turkey and Iraq). “One of our three animals, which we named E 24, had a light-colored coat with black spots – a typical feature of domesticated pigs”, stated Krause-Kyora, explaining its classification. The alteration of the coat color can be determined by a genetic analysis of the melanocortin 1 receptor (MC1R) gene in the aDNA. “Wild boar have an inconspicuous grey coat that provides good camouflage in natural surroundings”, mentioned Almut Nebel. The color of the coat was possibly one motivation for the Ertebølle people to want to possess such animals: “These animals with the new coat color were striking, since only grey wild boar had been known for centuries”, explained Nebel, “and it is conceivable that this ‘new fashion’ was as popular as the newest smart phones today.

For their research, the Kiel scientists received valuable support from the Institute of Legal Medicine and the Institute of Pre- and Protohistoric Archaeology at Kiel University, the State Archaeological Museum at Gottorf Castle as well as from the University of Aberdeen and the University of Durham. British colleagues verified the results from Kiel independently by repeating some of the molecular genetic analyses with the same original material. Additionally, they provided the results of an archaeozoological investigation, in which the size, form and position of the ancient teeth were analysed and compared to a modern reference collection. This provided further evidence that E24 must have been a domestic pig, which is supported by the form and the size of the molars.

With the help of agarose gel electrophoresis, PCR-amplified ancient DNA fragments can be separated by their size and then specified by comparison with DNA molecules of known size.

“The successful investigation in the Northern German region indicates that newer, multidisciplinary approaches are necessary in order to research potential contact zones between hunters and farmers”, states Ben Krause-Kyora. As in the current case, in which social contact could be shown from the presence of domestic pigs, Krause-Kyora and Nebel are convinced that archaeology, archaeozoology and molecular biology could provide further valuable results on cultural contact for other areas of Europe and the world.

The Graduate School Human Development in Landscapes is an interdisciplinary consortium of 15 institutes of 6 faculties at Kiel University, the Leibniz Institute for Science and Mathematics Education (IPN), and the State Archaeological Museum at Gottorf Castle. The PhD candidates of the Graduate School carry out research on the interactions between humans and nature in the past and are supervised by experienced scientists. Ben Krause-Kyora belongs to the group of the first highly-qualified graduates and he now leads the aDNA laboratory as a postdoctoral fellow and supports the setup of a new, state-of-the-art laboratory as well. Many of the PhD projects in the Graduate School are designed as cross-disciplinary investigations and combine, for example, archaeology, computer science, geo-sciences, physics, genetics and ancient history. The focus of the research is concerned with the complex interplay of natural, social and cultural factors, which take part in the development of human societies in landscapes. The Graduate School was established in 2007 within the framework of the Excellence Initiative.

Link to the original publication in Nature Communications:
http://dx.doi.org/10.1038/ncomms3348

Photos: Copyright Graduate School Human Development in Landscapes (GSHDL)