The Importance of Ancient DNA to Unravel the Evolutionary History of Domestic Animals

Domestication of animals and plants facilitated agricultural economies that then led to major cultural developments including the emergence of urban societies. Models of animal domestication pathways include commensalism which implies that animals are first domesticated without deliberate human forethought and action. This model of domestication has been suggested to fit many animal taxa, including pigs. In addition, because of commensalism pathway and the presence of the wild ancestor of domestic pigs (Sus scrofa) all across Eurasia, gene-flow between wild and domestic pigs may have been common throughout history. Here we present the results of a population genetics model for the domestication of pigs in Europe and Asia, using over 70 whole genomes of modern wild and domestic pigs. Our results show that large scale introgression between wild and domestic pigs has taken place since domestication and that this phenomenon drastically reduces our ability to obtain reliable estimate of parameters such as time and geographic origin of domestication. We then discuss how ancient DNA can resolve these shortcomings. In addition, we further suggest how ancient DNA could be invaluable to inform modelisation attempts that aim at indentifying how many times or how many places domestication pathways took place.