June 20, 2017
Ancient DNA reveals how cats domesticated humans
While dogs are believed to be the first animal to be domesticated, cats – as one might expect from a feline – took their sweet time trying to decide whether or not they wanted to bond with humans, according to a new, comprehensive genetic analysis published this week.
The authors of the study, which appeared in the journal Nature Ecology & Evolution, looked at the DNA of around 200 feline species representing more than 9,000 years, including mummified Egyptian cats and modern-day African wildcats, National Geographic reported on Monday.Based on that analysis, the researchers concluded that felines lived alongside humans for several thousand years before actually becoming domesticated, and that the earliest ancestors of today’s housecats came to Europe from southwest Asia as early as 4400 BC, the publication added.
Lead author Claudio Ottoni, a paleogeneticist from the University of Leuven, and his colleagues analyzed DNA from the bones, teeth, skin and hair of 100 to 9,000-year-old felines discovered at archeological sites in Western Asia, Europe and Africa. They found that all modern-day cats can be traced back genetically to the African wildcat (Felis silvestris lybica), a subspecies of wildcat found in North Africa and the Near East, according to a press release.
Furthermore, as Ottoni told Nat Geo, the first encounter between humans and felines most likely took place between 8,000 and 10,000 years ago in the Fertile Crescent, as cats opted to enter into a mutually-beneficial partnership as the unofficial rodent-hunter for humans. In short, people did not domesticate cats – cats decided to allow themselves to become domesticated, he said.
Trait-specific breeding doesn’t show up until the 19th century
The researchers also found that a second feline lineage comprised of African cats found all over Egypt spread into the Mediterranean and throughout most of the Old World by around 1500 BC, according to Nat Geo. This lineage, the study authors said, likely were tame and social, traits that would have made them appealing companions for humans as they traveled.
Unlike dogs, which were extensively bred to alter their appearance and body shape, the genes of cats have changed very little throughout the course of history, the researchers found. The notable exception is the distinctive dots and stripes of the tabby cat, which the DNA analysis showed had first appeared in Turkey in the 1300s, according to NBC News.
While the genes for the tabby cat coat can be traced back to the Ottoman Empire, Nat Geo said that the analysis found that they did not become common on domesticated felines until the 18th century. The first selective breeding among cats did not appear until the 1800s, they noted. This marked a seminal point in the human-feline relationship, said Ars Technica: it was the first time that people assumed control of cat breeding, as they had done with other domestic species.
“The comprehensive aDNA [ancient DNA] genetic study of cats across time and space that we present, provides answers to longstanding questions concerning the domestication process of the cat and contributes to a better understanding of how humans have reshaped global biodiversity through species translocations,” Ottoni and his colleagues explained in their paper.
“By revealing the original phylogeographic distribution of wildcats and its profound modification through human-mediated dispersal of tamed cats through time, we show that both Near Eastern and Egyptian cat lineages contributed at different times to the maternal genetic pool of domestic cats,” the study authors wrote. Feline domestication, they added, was “a complex, long-term process featuring extensive translocations that allowed admixture events between geographically separated cat populations at different points in time.”
Image credit: Erike Leong/Unsplash