Were cats domesticated twice?

The relationship between humans and cats, it turns out, has always been complicated.

The oldest archaeological evidence for domesticated cats can be traced back to 7500 BC, on the Mediterranean island of Cyprus. All domestic cats today, for the most part, are related to that subspecies – Felis silvestris lybica, or the Near Eastern wildcat.

But a new analysis of cat bones found in the Chinese village of Quanhucun suggests that there was a second domestication of cats, this time with a different species.

Using a differentiation method called geometric morphometrics, researchers led by Jean-Denis Vigne, the director of research at the French National Centre for Scientific Research in Paris, were able to conclude that the Chinese cat bones, dating back to about 5,300 years ago, do not belong to the Near Eastern wildcat species. Rather, they much more closely resemble the local leopard cat, or Prionailurus bengalensis.

Published Friday in the journal PLOS ONE, the study proves that the furry creatures we keep as pets today were, in fact, domesticated twice.

When the bones in question, a pelvis and mandible, were unearthed in central China 15 years ago, scientists weren’t sure if they were related to the Near Eastern wildcats and wondered if they came to the Chinese farming villages through trade routes from the Middle East. These felines would have been already domesticated, after all.

But Dr. Vigne, a zooarchaeologist, and his team, were able to prove otherwise by taking meticulous measurements of the size and shapes of the bones. And after confirming that they unequivocally belonged to leopard cats, his team pointed to evidence suggesting that they were also domesticated. Cats are very good predators of small animals – an appealing skill for the farm fields in the villages.

For instance, the cats at hand are smaller than their wild leopard counterparts – an earmark of domestication. There was also at least one cat buried as a complete body, indicating that it was not eaten. The excessive wear of their teeth is another hint of domestication, suggesting that the cats were fed by humans.

“That’s evidence of special treatment,”  Vigne tells Science magazine. “Even if what we’re seeing here is not full domestication, it’s an intensification of the relationship between cats and humans.”

If these wildcats indeed marked the second instance of the domestication of cats, it could shift the the entire understanding of domestication, scientists say.

In the case of the cats, according to Fiona Marshall, a zooarchaeologist at Washington University in St. Louis in Missouri, they had largely domesticated themselves. If it happened twice, she said, other animals may have become domesticated in a similar way as well, without as much human involvement as we traditionally believe.

"This is very important work that should have a great impact,” she told Science magazine. “This is the leading edge in a shift in thinking about domestication processes.”