Rover over time, from evolution to genetic design

With the scent of a bloodhound, the smarts of a German shepherd and the tenacity of a terrier, "Nature's" compelling "Dogs That Changed the World" attempts to track down the origin of man's best friend and determine what's ahead for genetically designed canines.

In the process, it compresses 15,000 years of history into a two-hour, best-in-show documentary, premiering at 8 tonight on KCTS-TV with Part 1, "The Rise of the Dog." Part 2, "Dogs by Design," airs at the same time next Sunday.

Narrated by F. Murray Abraham, the documentary moves with bristling energy, immaculate clarity and interpretive boldness, deploying graphics, superb film footage and an interesting mix of expert commentary to capture how the species has won its way into the hearts of man worldwide.

Pups through the ages

Part 1 is a colorful mosaic that explores the Arctic, Jordan, Mexico, Britain and Papua New Guinea, examining the dog's versatility and myriad cultural roles, from hunter to hauler and from spiritual protector to household companion and guardian.

These include the muscular sled-pulling dogs of the native Inuit, the speed-burning Salukis of the Jordanians, the crafty border collies of British shepherds, the hairless Xolos of the Aztecs and the singing dogs of aborigines in Papua New Guinea.

Each culture's dependence on the dog shows how our relationship with it has grown to become the most meaningful we have with any animal.

From wolf to woof

But first things first: From what and where did the incredible modern-day dog evolve?

Renowned canine historian Dr. Raymond Coppinger, of Hampshire College, Mass., contends the lure of leftovers at camp sites thousands of years ago set the stage for man's eventual relationship with the wolf, always believed to be the predecessor to the dog.

Some early wolves, he says, were scavengers, and they took what man would give them, from bones to food, at these so-called garbage dumps. Slowly, they became less fearful of humans and recognized them as friends, to the point they became domesticated.

Not all wolves, however, followed that path, many choosing to remain wild packs of hunters.

Historians have differed as to the animal's origin. Swedish geneticist Peter Savolainen's evolutionary-tree study of DNA gleaned from more than 3,000 dogs worldwide pinpoints the "motherland" as East Asia approximately 15,000 years ago. He found dogs from that area had the highest level of DNA variability, suggesting that was the birthplace of the domesticated dog.

Man's ability to morph the wolf and contour it into an animal to meet his needs is nothing short of amazing, as the documentary reflects in hunting, herding and sled-pulling scenes amid steep terrain and intense climate challenges.

Messing with our mutts

The second hour, "Dogs by Design," is an unvarnished portrayal of how man has altered the standards of numerous breeds, leaving some as genetic time bombs with problems ranging from structure to skin, eyes and teeth.

As man's dependence on the species changes from early-day livelihood as hunter and herder to modern-day police, military, drug, arson and assistance companion, we must prioritize structure and temperament over looks, says Abraham. "Hard-wiring," or in-breeding, is perpetuating much of the problem, experts claim, prompting a combustible relationship between owner and animal that results in millions of dogs facing euthanasia annually in animal shelters nationwide.

This "evolutionary miracle in 150 years," says Abraham, has transformed the dog into the most varied species, with more shapes and sizes than any other (400-plus breeds are recognized worldwide). Evolutionary scientist Dr. Susan Crockford, of the University of Victoria (B.C.), believes some of that can be explained by thyroxine, a hormone that controls dogs' growth rate. Basically, she argues, thyroxine rhythms cause different body parts to grow at different rates during pre- and postnatal development, giving breeds varying body shapes and physiology.

While energetic, passionate and powerfully imaginative, "Dogs That Changed the World" stretches a sensitive nerve with its intensity and grittiness. For better or worse, its resonating howl is that that the choices we make today will shape the breeds of tomorrow.

Ranny Green: rgreen@seattletimes.com