SCIENCE

Thousands of years before cats came to dominate Internet culture, they swept through ancient Eurasia and Africa, carried by farmers, mariners and even Vikings. So finds the first large-scale look at ancient-cat DNA. (Nature)

Use our video study guide to explore the origins of the domestic cat.

Teachers, scroll down for a quick list of key resources in our Teachers Toolkit.

Discussion Ideas

• For the first time, geneticists have traced how domestic cats spread around the Old World. When were wildcats first domesticated?
  • Even researchers aren’t quite sure. According to Nature, scientists still know “little about cat domestication, and there is active debate over whether the house cat is truly a domestic animal—that is, its behavior and anatomy are clearly distinct from those of wild relatives.”
  • Having said that, most scientists put cat domestication at about 10,000 years ago, after dogs, goats, sheep, and pigs were domesticated.

• How did scientists determine how house cats spread around the world (or, at least, the Old World)?
  • Geneticists analyzed the mitochondrial DNA of 209 domestic cats found at 30 archaeological sites in Europe, Africa, and the Middle East. Nature says “The samples dated from the Mesolithic—the period just before the advent of agriculture, when humans lived as hunter–gatherers—up to the 18th century.”

• Researchers think that cat populations had two growth spurts since domestication. What was the first “wave” of cat population growth?
  • The first wave came with the first agricultural revolution about 12,000 years ago, the period during which cats were initially domesticated.
    • The wild ancestors of domestic cats are native to the Fertile Crescent, the Arabian Peninsula, and North Africa. When early farmers in this region began storing grain, they likely attracted rodents. These rodents likely attracted wildcats. Farmers probably realized the value in having cats control rodent populations and encouraged them to adapt to life with humans.
    • Cats spread throughout the Eastern Mediterranean and North Africa. A 9,500-year-old human burial in Cyprus included cat bones, indicating that cats were a familiar household presence in the region by that time.
    • Cats were probably first domesticated in China about 5,300 years ago. Geneticists think these cats may have been the result of trade or wildcats that were independently domesticated by Neolithic Chinese farmers. Stay tuned.

• What was the second “wave” of cat population growth?
  • Seafarers starting in the 300s BCE likely contributed to the second wave of domestic cats spreading throughout the Old World. Explorers and traders probably kept cats on ships to control rodents, spreading kitties to port cities throughout Europe and sub-Saharan Africa.
    • Most of these early seafaring cats had Egyptian lineage. Cats with Egyptian mitochondrial DNA were identified in Bulgaria, Turkey, and, memorably, a Viking site in North Germany. “There are so many interesting observations” in the study, says Pontus Skoglund, a population geneticist at Harvard Medical School. “I didn’t even know there were Viking cats.”

TEACHERS TOOLKIT

Nature: How cats conquered the world (and a few Viking ships)

Nat Geo: Cat Diversity study guide

Genetics Home Reference: What is mitochondrial DNA?