By Nasos Skaltsas and Chris Spiratos (A class)

Before humans milked cows, herded goats or raised hogs, before they written language, before they had permanent homes, and most certainly before they had cats, they had dogs.

Or dogs had them, depending on how anyone views the relationship between humans and dogs. But scientists are still debating exactly when and where the ancient bond originated. And a large new study being run out, with scientists around the world, may soon provide some answers.

Scientists have come up with a broad picture of the origins of dogs. First off, researchers agree that they evolved from ancient wolves. Scientists once thought that some visionary hunter-gatherer nabbed a wolf puppy from its family one day and started raising tamer and tamer wolves. This is oversimplified, of course, but the essence of the idea is that people   bred wolves to become dogs just the way they now breed dogs to be tiny or large, or to herd sheep.

The prevailing opinion now, however, is that this origin story does not pass muster. Wolves are hard to tame, even as puppies and many researchers find it much more logical that dogs, in effect, invented themselves.