Why did early human ancestors keep dog's ancestors?

I wish I had a name or web site to send you to. There is a researcher in Russia that has had a project going for a number of years where she was using foxes from the fur trade. She would select the friendliest foxes, the ones most willing to seek attention from humans, and she would breed those and select the friendliest of their offspring to breed, etc. She discovered that in only a few years, there were marked differences in the apearance and personality of the foxes, making them more like domestic dogs than wild animals. I saw this on a nature show, and I believe it was also written up in National Geographic Magazine. It is strongly believed by anthropologists that humans did not set out to domesticate wild canids. The wild canids were as much scavenger as hunter, and they discovered that these strange ape-like beings had a lot of tasty scraps when they went hunting, and hanging around where they lived was an easy way to a good meal. The more outgoing and trusting settled in near the humans, taught their pups about this good foodsource, and maybe followed them on hunts. When they flushed game the way they would do for the pack, the humans saw the value of having them around. The friendliest of the offspring moved in with the humans, and eventually subsequent generations looked to the humans as their pack. Science has always agreed this is how domestication happened, but they thought it took hundreds or thousands of years. The Russian researcher proved it takes a lot less time than they thought. Our ancesters didn't "try to keep wolves"; it was a mutually beneficial partnership that evolved into dogs working for the benefit of the humans and the dogs finding the safety and benefits living with this human pack. And as humans encouraged certain dogs for their speed, or strength or good noses and kept the best of their offspring around, we had a sort of Darwinian evolution of the first breeds. Many of the breeds we have today are deliberate creations of breeders during the 17 and 1800's.