An international group of canine geneticists reports in the January 16, 2014, issue of PLoS Genetics that analysis of the nuclear genome of selected dogs and wolves reveals that they split from a common ancestor between 11,000 and 16,000 years ago but continued to crossbreed for many generations to come. Hedging their bets on the timing of the split, they say it could have come as early as 34,000 years ago, depending on the genetic-mutation rate and generation times one accepts. The article is available online here.
If the results sound familiar, it is because they are. The same group, with Adam Freedman of Harvard University as lead author and John Novembre of the University of Chicago as senior or corresponding author, reported much the same last May 31 in a paper posted to arXiv preprint server, an open source initiative for making scientific results available before publication in a journal. PLoS Genetics has now published a revised, peer-reviewed version of the manuscript. My posting on the original paper can be found here.