Dogs were the first thing humans domesticated—before any plant, before any other animal. Yet scientists have argued for years over where and when they arose. Some studies suggest that canines evolved in Europe, others Asia, with time frames ranging from 15,000 to more than 30,000 years ago. Now, an unprecedented collaboration of archaeologists and geneticists has brought the warring camps together for the first time. The group is analyzing thousands of bones from around the world, employing new techniques, and trying to put aside years of bad blood and bruised egos. If it succeeds, it will uncover the history of man's oldest friend—and solve one of the greatest mysteries of domestication.

To read the full story, see the 17 April issue of Science.

For more on man's best friend, see Science's latest coverage of doggy science.