The time when dogs began

-A A +A
By Roger Snodgrass

SANTA FE — Sometimes it takes more than a good speaker and subject to bring off a satisfying evening of scientific infotainment.

The right place, the right atmosphere, the right size audience and the right mix of people and animals may also play a role.

Thomas Leitner, a biological theorist at Los Alamos National Laboratory took care of the first requirement Tuesday night with an accomplished presentation on his search for the birth of the dog.

More precisely, Leitner recounted a series of increasingly complex studies to narrow down the questions of where, when, how and why wolves — who are dogs’ immediate ancestors — became domesticated. By analyzing mitochondrial DNA, one of the basic metrics of evolutionary research, he has tried with partial success to answer each of those questions. And he also has a few theories on the ones he hasn’t answered yet.

Leitner and his collaborators now probably can make as good a case as anybody in the world that the multiplicity of breeds of dogs – from the Mexican Hairless to the Great Dane and every mutt in between – have descended from at least 48 gray wolves in the area south of the Yangtze River in China.

The “where” question was answered by pinpointing the geographic area with the greatest genetic variation, while the “when” was discovered by figuring out the pace of the molecular clock that governs genetic change, a rough average of how long it took for so many mutations to have occurred.

The answer to when it happened is still a little less than satisfying – because mathematically, the range is expressed as between 4,600 and 16,200 years ago.

“I say less than 16,000 years,” Leitner said, a number that corresponds to the earliest known archeological remains, a dog jaw found in Germany about 14,000 years ago.

Progressing from a preliminary study involving 102 dogs of 52 different breeds and two captive wolves, Leitner and partners learned enough each time to want more samples, engaging people throughout in a far-flung search for what ultimately became more than 1,500 samples.

There is still no hard evidence for “why” the wolves were domesticated, although the count of 48 instances suggests it was “pretty widespread,” Leitner said. “It was not a chance thing.”

He does not claim to answer the “why” or the “how” yet.

The fact that the Yangtze people were among the first to settle into agricultural communities may be a clue, but theories include a domesticated wolf’s value as a hunting companion. The likelihood is that wolves might have chosen to live close to human settlements where scraps of food could be available, and the tradition of dog-eating as a protein source in some cultures started.

“Personally, I think its probably a combination of these things,” Leitner said.

Leitner invited members of the audience with unusual breeds to donate “a few hair shafts — with the root — for ongoing research on dog evolution.

Leitner’s talk was the first in a new array of scientific talks, “The q-bio Public Lecture Series,” sponsored by LANL’s Center for Non-Linear Studies (CNLS) and set in the Santa Fe Complex, a new community studio space proposing to create “connections across science, technology and art.”

The space was conducive, although barely enough for a standing-room-only crowd of about 80 people and about three dogs who growled or barked only at appropriate times during the evening.

The audience seemed self-selected for intelligence. Entranced by the subject and the scientific process, they tossed pointed questions directly at the speaker and his subject rather than calling attention to themselves.

CNLS Director Robert Ecke described quantum biology (q-bio) in his introduction as a discipline for applying quantitative methods to understanding biology at a deeper level, a field that is beginning to mature in the twenty-first century.