To my mind, there’s no excuse for cats. They’re animal hipsters — preening, demanding and terribly full of themselves. Plus they make me sneeze. Yes, they catch mice, but that’s why we invented the glue trap.
I’m told this might be an unpopular position.
I’ve always blamed the Felis silvestris lybica — the Near Eastern wildcat — for the scourge that is the half a billion domesticated cats that slink and mew and shed hair all over the world today. Mitochondrial DNA traces modern cats back to the long-ago Felis, which bears a physical resemblance to the contemporary model in addition to a shared genetic past. What has never been known is exactly when true domestication took place, with possible dates ranging from as far back as 9,500 years ago (based on wildcat remains buried near human remains on Cyprus) to 4,000 years ago (when domesticated cats first began appearing in Egyptian art) to as recently as 2,300 years ago, based on DNA evidence and archaeological digs.
Now, a study in Proceedings of the National Academy of Sciences splits the difference, offering a satisfyingly precise date: cats first moved into our homes 5,300 years ago — and for better or worse, have refused to leave since.
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The threshold of all domestication is traditionally thought of as the point at which a human-animal relationship becomes what’s known as commensal — when the animal begins eating from the human-food supply and the humans know it and permit it. Rodents and crop-scavenging crows do not have a commensal relationship with us, even though they eat themselves full at our table. House pets and farm animals do.
The investigators in the current study, led by Yaowu Hu, of the Chinese Academy of Sciences, excavated a site in Shaanxi, China, where an agricultural village was known to have stood less than 6,000 years ago. The scientists unearthed cat skeletons buried within the boundaries of the village that were physically similar to wildcats but smaller — well within the range of domesticated cats. As with many such skeletal troves, it was not easy to determine exactly how many individuals contributed to the tangle of bones, but the investigators were certain of at least two. Carbon dating gave a slightly different age estimate for both, which averaged out to 5,300 years.
The key to determining what the animals ate and whether that indicated domestication was to analyze the bones in a different way — this time using isotope analysis to detect the particular mix of minerals and other nutrients that went into building the skeleton in the first place. One elemental profile would indicate a meat-heavy diet; another plant- or grain-based; another, different combinations of all of them.
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In general, the cats — like the humans at the site — showed evidence of a diet heavy in millet, a grain that was clearly part of the local crop and is especially useful because farm animals eat it too. The cats did eat meat-based proteins, though not as much as they would have if they’d been living in the wild and doing what they do best, which is hunting smaller animals.
The source of the meat the cats did eat is not a mystery. It’s possible the humans gave them scraps, but then as now, meat is difficult and expensive to raise and would likely have been saved for the villagers. There were, however, plentiful mice and rats around, and their skeletons indicated that they enjoyed millet too — something the humans would not have tolerated for long. Ceramic jugs with heavy tops, also found at the site, were likely used as rodent-resistant ways to store grains. But a better solution was simply to let the cats have at the pests, a job they performed quite happily.
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That scenario is perfectly in keeping with most theories of cat domestication, in which the invention of agriculture led to the accumulation of food stores, which in turn attracted scavengers and in further turn required some kind of predatory counterweight. Enter the cat. Dogs were domesticated in a similar mutually beneficial way, though in their case the service they performed was about guarding the campsite and warning of intruders.
And which came first — dogs or cats? No contest here. Canine domestication occurred 18,000 to 32,000 years ago — in Europe, according to a new study. It is a matter of history that we did not stop there, that we reckoned if dogs were nice, cats would be too. It is also a matter of history — not to mention a few billion cute-cat YouTube hits — that such thinking proved popular. The videos, at least, don’t make you sneeze.