Humans formed close bonds with cats after they transitioned from hunter-gatherers to farmers nearly 10,000 years ago, when felines began to control pests in early civilizations, a new study has confirmed.
The research, recently published in the journal Inheritancesuggests that the world’s first domestication of cats was sparked by this lifestyle transition that led humans to establish ever-larger settlements after the invention of agriculture.
The wild animals that lived around 12,000 years ago took advantage of the increased density of rodents around the first grain stores, and early human societies also benefited from the cats that caught these vermin, according to researchers from the University of Missouri in the US.
The domestication of the cat began as a beneficial relationship between feral people and the developing agricultural societies of the Fertile Crescent – the crescent-shaped region of the Middle East that includes present-day Syria, Iraq, Lebanon, Palestine, Israel and Jordan.
In the study, scientists collected and analyzed DNA from cats in and around the Fertile Crescent, as well as across Europe, Asia and Africa.
The researchers compared almost 200 different genetic markers, and evaluated the sequence of the basic molecules of DNA: adenine, guanine, thymine and cytosine.
They looked at markers known as microsatellites, which are sections of repetitive DNA bases that mutate very quickly and can provide clues about recent cat populations and breed development over the past 100 years.
The scientists also evaluated and compared other DNA markers, known as single nucleotide polymorphisms (SNPs), which are single-base molecular changes throughout the genome.
SNPs can provide clues to their ancient history going back several thousand years.
“By analyzing and comparing the two markers, we can begin to piece together the evolutionary story of cats,” explains study author Leslie A Lyons.
The findings suggested that cats were only domesticated on the Fertile Crescent around 12,000 years ago.
Then, as humans began to travel the world, they brought their new feline companions with them, the researchers noted.
Over thousands of years, as feline genes have been passed down from generation to generation, the genetic makeup of cats around the world has diverged.
Citing one example, the scientists said the genetic makeup of cats in western Europe is now very different from that of Southeast Asia, a process known as “isolation by distance”.
This is in contrast to what research has shown about horses and cattle, which probably saw the domestication event caused by humans in different parts of the world at different times.
“We can actually consider cats semi-domestic because if we released them into the wild, they would probably hunt pests and be able to survive and socialize on their own because of their natural behaviors,” explained Dr. Lyons. He has been researching feline genetics for over 30 years.
“Unlike dogs and other domesticated animals, we haven’t changed the behavior of cats that much during the domestication process, so cats once again prove that they are a special animal,” he said.
Scientists call for further research, including data from other wild species in Iraq, Iran, the Indus Valley region and northwest India, to further explain the genetic variation seen in cat populations.
“Genetic and archaeological studies of agricultural cats would be an important addition to further elucidate the domestication process of cats,” the researchers wrote in the study.