DNA tells pigs’ tale of diverse ancestry

People initially bred wild boars into domesticated pigs in at least seven different parts of Asia and Europe, a new genetic study suggests. The finding counters the widely held view that pigs were domesticated in only two regions, located in what’s now Turkey and China, starting around 9,000 years ago.

The new genetic data indicate that the know-how to domesticate wild boars spread rapidly across much of the world, an international team concludes in the March 11 Science. The data also make it unlikely that farmers migrating out of one or two areas brought pigs with them to new locales, the researchers contend.

Led by zoology graduate student Greger Larson of the University of Oxford in England, the team analyzed the sequences of DNA from 686 modern pigs and wild boars living in various parts of Asia and Europe. The genetic material came from cells’ mitochondria. A computer program identified characteristic genetic sequences that appeared in specific locales of the DNA and mapped out evolutionary links among animal groups with different mitochondrial-DNA signatures.

On the basis of that analysis, the researchers argue that initial wild boar populations lived on islands near Southeast Asia’s coast and eventually reached much of Asia and Europe. Independent pig lineages arose on Southeast Asia’s mainland and on its islands as well as in what’s now India, China, New Zealand, the Middle East, and Europe.

Cattle are another story. Prior mitochondrial-DNA analyses, conducted by other researchers, indicate that the undomesticated ancestors of modern cattle originated in the Middle East and were brought to Europe by early farmers.

It will take more-extensive genetic studies to determine whether pigs and cattle took different paths to domestication, Larson says.

Bruce Bower has written about the behavioral sciences for Science News since 1984. He writes about psychology, anthropology, archaeology and mental health issues.

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