‘Archaeologists have long known that people started to domesticate animals for food at the dawn of agriculture in the Fertile Crescent (the curve of land across the Middle East from the Mediterranean to the Persian Gulf) about 10,000 years ago. But details of the complex pathways through which improved livestock spread across Europe and Asia are only now emerging, as genomic technology makes it practical to compare the DNA of hundreds of animals across continents. . . . ‘A Chinese consortium led the sheep study in collaboration with the International Livestock Research Institute in Nairobi; it is published in the journal Molecular Biology and Evolution.