The fierce Vikings may have had a soft spot for cats thousands of years before they came to dominate internet culture, according to a new study which suggests that felines travelled through ancient Eurasia and Africa alongside early farmers and ancient mariners.
In the first large-scale study of ancient-cat DNA, researchers sequenced DNA from more than 200 cats that lived between about 15,000 years ago and the 18th century AD.
Researchers know little about cat domestication, and there is active debate over whether the house cat (Felis silvestris) is truly a domestic animal – that is, its behaviour and anatomy are clearly distinct from those of wild relatives.
“We don’t know the history of ancient cats. We do not know their origin, we don’t know how their dispersal occurred,” said Eva-Maria Geigl, from the Institut Jacques Monod in France.
A 9,500-year-old human burial from Cyprus also contained the remains of a cat. This suggests that the affiliation between people and felines dates at least as far back as the dawn of agriculture, which occurred in the nearby Fertile Crescent beginning around 12,000 years ago.
Ancient Egyptians may have tamed wild cats some 6,000 years ago, and under later Egyptian dynasties, cats were mummified by the million.
Researchers analysed DNA from the remains of 209 cats from more than 30 archaeological sites across Europe, the Middle East and Africa.
The samples dated from the Mesolithic – the period just before the advent of agriculture, when humans lived as hunter–gatherers – up to the eighteenth century.
Cat populations seem to have grown in two waves, the researchers said.
Middle Eastern wild cats with a particular mitochondrial lineage expanded with early farming communities to the eastern Mediterranean.
Geigl found that grain stockpiles associated with these early farming communities attracted rodents, which in turn drew wild cats. After seeing the benefit of having cats around, humans might have begun to tame these cats.
Thousands of years later, cats descended from those in Egypt spread rapidly around Eurasia and Africa.
Sea-faring people probably kept cats to keep rodents in check, said Geigl, whose team also found cat remains with this maternal DNA lineage at a Viking site dating to between the eighth and 11th century AD in northern Germany.
Researchers believe that nuclear DNA – which provides information about an individual’s ancestors – could address lingering questions about cat domestication and spread, such as their relationship to wild cats, with which they still interbreed.
Geigl’s team also analysed nuclear DNA sequences known to give tabby cats blotched coats, and found that the mutation responsible did not appear until the Medieval period.