When archaeologists unearthed small cat bones in China dating back some 5,400 years, they figured cats had been hanging out in early Chinese farming settlements since the Neolithic Period.
Now, a sweeping new DNA study has confirmed what earlier studies had suspected: that those felines weren't typical domestic cats, but a different species altogether.
A team led by evolutionary scientists at Peking University analyzed the mitochondrial DNA of 22 feline bones from 14 sites in China, across 5,400 years of history. Intriguingly, domestic cats (Felis catus) didn't appear in China until the 7th century.
So what was the cat-like creature living alongside Chinese farmers for some 4,000 years before that? The team found that the older specimens belonged to the leopard cat (Prionailurus bengalensis), a wild species native across South, Southeast and East Asia, which is not a direct ancestor of domestic cats.
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The DNA tells an intriguing story of the role of cats in ancient China, in parallel with ancient art and historical texts.
It appears that leopard cats may have enjoyed a life of semi-domestication in China for millennia, where perhaps they exploited the food and relative shelter of farming communities, but continued to roam free. The remains of leopard cats, found throughout human settlements from the time, were dated to between 3400 BCE and 200 CE.
Interestingly, there seemed to be no crossover between leopard and domestic cats. Not only was there no trace of leopard cat DNA in the genomes of later domestic cats, but there was also a strange gap of several centuries between the two species. The earliest domestic cat remains were dated to around 730 CE.
The researchers also figured out what this oldest known domestic cat probably looked like. By reconstructing its genome, they deduced that it likely had short fur and was either fully white or partially white with spots. It also had some maternal genes from the African wildcat, believed to be the most likely ancestor of domestic cats.
Cultural depictions back up the timeline drawn from DNA evidence. Older appearances of cats in art and writing seem to be of leopard cats, before a clear switch around the time domestic cats appeared.
"The oldest written accounts with [a] clear description of domestic cats also coincide with this period, including a Tang Dynasty story in which the Empress presents a pet cat to her ministers," the team writes in their published paper.
"These historical records hint that domestic cats were regarded as exotic pets and were likely kept among the ancient Chinese elite, reflecting their relatively recent introduction to China."
The timing suggests that domestic cats were introduced to China via the ancient Silk Road trade route, the team says. Once there, they took over the role that leopard cats had previously filled in those human communities, which had declined centuries earlier, possibly due to a turbulent era between dynasties.
"The arrival of domestic cats may have hindered the re-establishment of leopard cats in human settlements, as both species occupy similar ecological niches," the researchers suggest.
"Additionally, the rise of poultry farming in ancient China after the Han Dynasty may have contributed to human-leopard cat conflict, given their tendency to prey on chickens, further preventing the return of leopard cats to anthropogenic environments."
It's an intriguing chapter in the history of the lazy furball curled up at the foot of your bed.
The research was published in the journal Cell Genomics.