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Friday, January 3, 2014

The origin of the Chinese cat

You hear a lot about how long ago dogs have been domesticated. What about cats? How long have they been our companions? It depends on the region. The Egyptians included pet cats in their artwork 4000 years ago, but they buried cats at least 1,500 years before that. Cats were thought to have made their appearance in Europe 3000 years ago, and in China only 2000 years ago. However, according to Yaowu Hu of the Chinese Academy of Sciences and others, the arrival date for the Chinese domestic cat is off by at least 3000 years.

The ancestry of the modern cat is not nearly as clear as it is for dogs, which are 100% evolved from wolves. Mitochondrial DNA suggests that domestic cats evolved from populations of Near Eastern wild cats. About 11,000 years ago, these wild cats moved into Cyprus, where, 9,500 years ago, one was interred next to a human. From Cyprus, the idea of keeping cats traveled around the world. When did it get to China?

To find out, the researchers conducted 14C dating plus other types of analysis on animal and human bones from archeological sites of the Yangshao culture (7000 to 5000 years ago). Sure enough, those bones included ones from a couple of cats that lived about 5,500 years ago.

Measurements of the bones showed that these ancient cats were larger than most modern cats but smaller than wildcats. This isn’t surprising for animals in the early stages of domestication.

But just how do we know the cats were domesticated? Two lines of evidence. First, the cat bones were found amongst the belongings of the villagers. Second, and even more compelling, isotope analysis showed that the Chinese cats had eaten a lot more millet grains than wild cats (which are obligate carnivores) normally do. In particular, one cat had lived to a very old age (for cats) on this high-grain diet. This is a strong indication that the cats were being fed, either deliberately or inadvertently, by humans.

This doesn’t necessarily imply that the Yangshao felt any particular affection toward their cats. They may have simply found cats useful deterrents to the plagues of mice and other rodents threatening their grain storage. The researchers didn’t note any artwork or burial practices indicating reverence for the animals, like that shown by the Egyptians. Nonetheless, it looks like cats were part of the Chinese lifestyle over 5000 years ago.

Hu Y, Hu S, Wang W, Wu X, Marshall FB, Chen X, Hou L, & Wang C (2013). Earliest evidence for commensal processes of cat domestication. Proceedings of the National Academy of Sciences of the United States of America PMID: 24344279.