Kids learn a couple basic truths about cats from a young age. They always land on their feet after a fall; they purr when they're happy; they chase mice. That last bit of common wisdom about cats may actually be the key to their domestication more than 5,000 years ago in China.
The setup: A new paper published in Proceedings of the National Academy of Sciences includes archeological evidence linking together a chain of events that led to the domestication of cats. In the beginning, we were but two species. In the end, we were united in a mutual war against the mice.
"The story begins with agriculture," writes The Atlantic. "About 5,560-5,280 years ago in the Shaanxi region of central China, humans were experiencing an agricultural boom...They had small villages, with clusters of homes, cemeteries, and communal areas. They kept pigs and dogs and grew crops, primarily millet but a bit of rice, too, which they kept in ceramic vessels. Now, these farmers had a bit of a problem: rodents."
You can probably guess where this story goes. There were cats around, and those cats ate the rodents, which kept the farmers' millet safe. Humans realized keeping the cats around was advantageous, so they didn't kill them, and even began to offer them food and shelter.
So that's the end of the story. It's logical, and unremarkable. But something about it is remarkable, if you ask this question: How did archeologists figure all this out? That story's more involved.
First, the basics: Archeologists discovered a rodent tunnel that led to a grain storage pit. They also discovered the bones of cats in various places. Easy enough. Now the crazy part: Scientists determined what the rodents had been eating (millet) and what the cats had been eating (rodents) by studying their 5000-year-old bones.
The paper's co-author, Fiona Marshall, told The Atlantic: "There are different photosynthesis pathways for plants in different places. If it's hotter or closer to the tropics, they more often have what we call a C4 pathway, whereas if it's cooler, they are more likely to have a C3 pathway. Where Quanhucun, [China] is, it's an area where the vegetation would be C3. The deer were clearly eating C3 plants. But the people and the pigs and the dogs, they were all eating C4 plants, and C4 had to come from the millet, which was cultivated and brought into that region. So it had a special signature of its own."
"The rodents and the cats all showed signs of that C4 pathway, indicating a path from human cultivation, to rodent, to cat," The Atlantic adds.
This is the earliest evidence that researchers have found of humans and cats living in harmony, but China likely wasn't the nexus of evolutionary domestication. The researchers suggest similar things probably happened in other parts of the world, as humans began farming and cats ate the rodents those farms attracted. Food was the key to how that relationship developed. Some pet owners would probably argue not much has changed in 5000 years.