The genetic study used DNA extracted from domestic cattle bones excavated in Iranian archaeological sites dating to not long after the invention of farming and in the region where cattle were first domesticated, a team of French, German and British researchers said.
The DNA sequences of those ancient cattle, as well as cattle living today, could only have arisen if a small number of animals, approximately 80, were domesticated from wild oxen, a University College London release said Tuesday.
"This is a surprisingly small number of cattle," UCL researcher Mark Thomas said. "We know from archaeological remains that the wild ancestors of modern-day cattle, known as aurochs, were common throughout Asia and Europe, so there would have been plenty of opportunities to capture and domesticate them."
Wild aurochs were very different from modern domestic cattle, the researchers said.
"They were much bigger than modern cattle, and wouldn't have had the domestic traits we see today, such as docility," said Joachim Burger of the University of Mainz in Germany.
"So capturing these animals in the first place would not have been easy, and even if some people did manage to snare them alive, their continued management and breeding would still have presented considerable challenges until they had been bred for smaller size and more docile behavior."