The Origin of the Domestic Pig: Independent Domestication and Subsequent Introgression

TLDR

The domestic pig originates from the Eurasian wild boar, and historical records show Asian pigs were introduced into Europe in the 18th and early 19th centuries. We sequenced mitochondrial DNA and nuclear genes from wild and domestic pigs across Asia and Europe. The study demonstrates independent domestication of European and Asian wild boar subspecies about 9,000 years ago, with ancestral divergence ~500,000 years ago, and reveals Asian pig introgression into Europe in the 18th–19th centuries, producing hybrid origins in major European breeds.

Abstract

Abstract The domestic pig originates from the Eurasian wild boar (Sus scrofa). We have sequenced mitochondrial DNA and nuclear genes from wild and domestic pigs from Asia and Europe. Clear evidence was obtained for domestication to have occurred independently from wild boar subspecies in Europe and Asia. The time since divergence of the ancestral forms was estimated at ~500,000 years, well before domestication ~9,000 years ago. Historical records indicate that Asian pigs were introduced into Europe during the 18th and early 19th centuries. We found molecular evidence for this introgression and the data indicated a hybrid origin of some major “European” pig breeds. The study is an advance in pig genetics and has important implications for the maintenance and utilization of genetic diversity in this livestock species.