The results of an international study describe the genetic development of the aurochs (Bos primigenius), the wild ancestor of domestic cattle, during and after the Ice Age. The central European subspecies was determined by means of gene sequencing. For this study, samples were used that were collected in the framework of Collaborative Research Centre 'Our Way to Europe' at the University of Cologne. The results of the study 'The genomic natural history of the aurochs' were published in Nature.
Back in 2014, Professor Dr Andreas Zimmermann and his colleague Dr Birgit Gehlen from the University of Cologne's Department of Prehistoric Archaeology had ten aurochs individuals dated at the Cologne Accelerator Mass Spectrometer (CologneAMS). The bones were excavated in the 1980s in Bedburg-Königshoven in what was then an open-cast brown coal mine. "They were contaminated by the preservative used at the time, which led to inconsistent and largely incorrect data," explained Gehlen. "The new dating within the framework of the CRC resulted in an age of approximately 11,700 years. This makes Bedburg-Königshoven one of the rare sites of the earliest Holocene in central Europe, an epoch that lasts from 11,700 years ago to the present day."
The dating to the earliest Mesolithic period and the relatively large number of aurochs bones – including some larger skull fragments – aroused the interest of Dr Amelie Scheu from the Palaeogenetic Working Group at Johannes Gutenberg University Mainz. She took samples from the ten aurochs. It turned out that the aDNA (ancient DNA) of two individuals was so well preserved that they were suitable for deep sequencing and further analyses. These were carried out in the following years as part of a project at Trinity College Dublin in Ireland.
The study revealed overall large genomic differences between the European aurochs, the North Asian aurochs and the South Asian ancestor that persisted throughout the last Ice Age, at least since the last common ancestor of eastern and western Bos primigenius approximately 90,000 years ago. After the peak of the last Ice Age, aurochs from the Iberian Peninsula recolonized central Europe. A period of migration and mixing began about 11,700 years ago with the significant climatic improvements at the beginning of the Holocene.
The results of the study also confirm earlier assumptions that people in the Stone Age rarely captured and isolated aurochs, and only within a specific historical time window. In addition, European domesticated cattle can be traced back to a small number of individuals from the wild ancestors in the Middle East around 11,000 years ago. This finding suggests that aurochs were kept by humans, including intentional feeding. It was therefore not a passive, gradual process, but a targeted domestication within a relatively short period of time.
"With the help of the samples from Bedburg-Königshoven, the genome of the central European aurochs could be fully decoded for the first time. It is now possible to better understand the history of European and Asian wild cattle and today's domestic cattle," said Dr Birgit Gehlen.
