Geneticists have deciphered the prehistory of aurochs — the animals that were the focus of some of the most iconic early human art — by analyzing 38 genomes harvested from bones dating across 50 millennia and stretching from Siberia to Britain. The aurochs roamed in Europe, Asia and Africa for hundreds of thousands of years. Adorned as paintings on many a cave wall, their domestication to create cattle gave us a harnessed source of muscle, meat and milk. Such was the influence of this domestication that today their descendants make up a third of the world’s mammalian biomass.