Genetic researchers have uncovered the ancient history of aurochs, the animals that inspired some of the most notable early human artworks, by examining 38 genomes extracted from bones that date back 50,000 years, covering regions from Siberia to Britain. Aurochs existed across Europe, Asia, and Africa for hundreds of thousands of years. Their domestication led to the development of modern cattle, providing a reliable source of strength, meat, and milk. The impact of this domestication is significant; their descendants currently account for one-third of the world’s mammal biomass.
An international team of researchers, including geneticists from Trinity College Dublin, has unveiled the prehistory of aurochs — animals that were central to some of the earliest human artistic expressions — by studying 38 genomes taken from bones spanning 50 millennia from Siberia to Britain.
Aurochs thrived in Europe, Asia, and Africa for many centuries. Traditionally depicted in cave paintings, their domestication allowed for the creation of cattle, which became a vital source of muscle, meat, and milk for humans. The legacy of their domestication is still felt today, with their descendants representing a third of all mammalian biomass on Earth.
Dr. Conor Rossi from Trinity, the lead author of a newly published article in the prominent journal Nature Communications, stated: “The aurochs vanished around 400 years ago, leaving many aspects of their evolutionary journey unknown. However, by sequencing ancient DNA, we have gained a better understanding of the diversity that existed in the wild and improved our knowledge of domestic cattle.”
Fossils of aurochs found in Europe date back to 650,000 years, roughly around the time early human species emerged on the continent. Notably, animals from the eastern and western extremes of Eurasia have a much more recent common ancestor, suggesting a replacement event occurred around 100,000 years ago, likely due to migrations out of a southern Asian origin.
This replacement process mirrors human prehistory, as it was incomplete; some remnants of the older lineage are still present in European aurochs.
Dr. Mikkel Sinding, a co-author and postdoctoral researcher at the University of Copenhagen’s Department of Biology, noted: “We often categorize European aurochs as one unified type, but our research indicates that there were three separate populations in Europe — a Western European, an Italian, and a Balkan variety. This reveals a level of diversity in wild aurochs that we had not previously appreciated.”
Interestingly, climate change also left its mark on aurochs genomes in two significant ways:
Firstly, genomes from European and northern Asian aurochs separated and began to diverge at the start of the last ice age around 100,000 years ago, and there was minimal mixing until the climate warmed again. Secondly, estimated population sizes based on genome data decreased during the glacial period, with European populations experiencing the most severe decline, retreating to isolated refuges in southern regions of the continent before repopulating afterward.
The greatest reduction in genetic diversity occurred between the time of domestication of the aurochs in northern Fertile Crescent just over 10,000 years ago and the emergence of the first cattle. Notably, just a few maternal lineages (as tracked through mitochondrial DNA passed from mothers to offspring) contributed to the cattle gene pool during this period.
“Though Caesar exaggerated by comparing them to elephants, the wild aurochs were undoubtedly formidable creatures, indicating that their initial capture and domestication likely involved only a small number of individuals,” explained Dan Bradley, a professor in Trinity’s School of Genetics and Microbiology, who led the research.
“Nevertheless, the limited genetic diversity of those early cattle was supplemented as they moved with their herders toward the west, east, and south. It is clear that early and widespread mating occurred with wild aurochs bulls, leaving a lasting legacy of the four distinct preglacial aurochs ancestries that can still be found in today’s domestic cattle.”
