ST. LOUIS, MISSOURI—Herders dating back to the Neolithic period did not isolate their domesticated charges from wild animals, according to Fiona Marshall of Washington University in St. Louis, Keith Dobney of the University of Aberdeen, Tim Denham of the Australian National University, and José Capriles of the Universidad de Tarapacá. They reviewed recent research on the domestication of large herbivores in different places and at different times. “Our findings show little control of breeding, particularly of domestic females, and indicate long-term gene flow, or interbreeding, between managed and wild animal populations,” Marshall told Science Daily. Such contact with wild animals may have been accidental or intentional, in order to produce stronger, faster animals better suited to the environment. “The boundaries between wild and domesticated animals were much more blurred for much longer than we had realized,” she added.