Many scientists, including biologists and psychologists, have come to the conclusion that wolves chose man, and not the other way around – which was a long-held belief.
Knowing that man would not likely chose to make a companion of a fierce predator who would not be a hunting companion, and, mindful of selective breeding by man, it seems far more likely that wolves made the initial approach. Those that preferred to scavenge from man’s garbage dumps rather than hunt may have had more benign dispositions to begin with. Overtime, those that applied their wolf pack cooperative skills to humans would have been allowed to stay and ultimately became vanguard dogs.
Now a group of scientists has published an article based on whole-genome sequencing of grey wolves, Chinese indigenous dogs, and diverse breeds of dogs. From a demographic analysis, these scientists concluded that the split between wolves and Chinese indigenous dogs occurred 32,000 years ago. So, dogs may have been under human selection for a much longer time than previously thought, perhaps by initially scavenging. (Nature Communications 4, Article Number 1860, published May 14, 2013)
From China, those early dogs spread around the world and remained in China, where they are known as Chinese native dogs. Dr. Ya-Ping Zhang, who led the international group of scientists, told the NY Times that the native dogs live on in rural villages, guarding homes.
Since it was only about 10,000 years ago that people settled in villages in East Asia to farm, these early dogs had to find hunter-gatherers. Once the split between dogs and wolves began, their genes evolved in a different direction. Genes involving smell and hearing were some that evolved early. Some are involved in a section of the brain where mammals make decisions about how to behave.
“The conventional view is that hunter-gatherers go out and get a puppy,” said Chung-I Wu of the University of Chicago, one of the authors. But if that were true, then dogs would have descended from a very small group. Instead, the scientists found that a large population of wolves began hanging around humans – likely scavenging.
The scientists are continuing to gather more DNA from wolves and dogs to see how variants of genes affect dog behavior today. Some of the same genes that evolved in dog brains also evolved in human brains. “Humans have had to tame themselves,” said Adam Boyko of Cornell University, a member of the group. “The process is probably similar to dogs –you have to tolerate the presence of others.” (NY Times, Carl Zimmer, May 16, 2013)