Sunday, April 02, 2017

Paleolithic Partners! The Dog in the Cave: The Wolves Who Made Us Human by Kay Frydenborg

A boy walks barefoot into a large cave in what is now modern southern France. Deep within the cave it's black as night, so he caries a torch made of juniper pitch to light his way. He stops to examine the elaborate display of artwork lining the cave walls around him. Does he, perhaps, sniff the dank air for the alarming scent of bear?
But he's not alone. For next to the child strides a large, wolflike dog. Their footprints, fossilized in the mud of the cave floor, reveal that the boy is about eight or ten years old. Those paw prints, the size of a grown man's hand, could have been left only by an animal neither a fully wild wolf nor a truly domesticated dog... a wolf-dog.

Darwin was a dog lover. After his major works were completed, he continued to muse over how the myriad and diverse breeds of dogs who served man could have evolved from a single species. And since his time, scientists have wondered how man and dog have come to walk together down those eons since that time 26,000 years ago when together they may have entered that cave.

The domestication of the dog is now thought to have begun between 40,000 and 26,000 years ago. Fossils found with human skeletons, for example, an elderly human with her hand upon the side of a puppy or a dog buried with a mammoth bone lovingly placed in his mouth, bear witness to this long and loving association. Ancient wolf dogs clearly lived with man and began their long descent as man's best friend.

But who domesticated whom? Scientists have not determined whether bold and highly social wolves took to hanging around human habitations, guarding and collecting scraps or whether humans, hearing wolves calling their pack to the chase, followed behind until the wolves circled their exhausted big prey, at last going in with their throwing spears to make the kill and share the spoils with the wolves. Perhaps both processes occurred at different times in many places. However, we now know that early humans and wolves had much in common. Powerful predators (although not apex predators separately), both lived in cooperative, communicative family groups and hunted by tracking and running down large animals, and when they combined their specialized skills, they rose to the top of the predatory heap and came to dominate their common habitats.

The theory of human-dog association is called co-evolution, in which the wolf dog evolved to become the working companion of humankind and humans changed as they benefited from their association. During the time of cohabitation, dogs changed significantly. Their heads broadened, their muzzles grew shorter and wider, their dentition changed, and their coats began to vary widely. Even our human brains changed at the same time--humans shed some of the part of their brains that interpreted sensory information--scent and hearing--and wolf dogs lost some of their cerebral cortex while retaining the sharp senses that made them essential to hunter-gatherer culture. With their dogs and their tools, homo sapiens overwhelmed Neanderthals and the Denisovans to become the dominant species on earth.

With the new scientific tools of carbon dating and DNA evaluation, much of dog-human history has been revealed, answering some of the Darwin's questions. Still, why do humans choose to live intimately with dogs, who still share 98.9% of their DNA with wolves, rather than our closest relatives, the chimpanzees, with which we share 96% of ours? Interestingly, in lab experiments, dogs, even young puppies, instinctively know to follow a human's eye movements or gestures like pointing to locate the hiding place of a object, just as human babies do. Even after long training, few chimps can match that performance. Why? Chimps are a rivalrous bunch, with clever minds of their own. But dogs are born to please their pack leader, their humans, and seem to prefer humans as companions to their own kind, and thus have evolved to be ideal helpmates.

The science of "dognition" (dog cognition) is still developing, with ongoing studies (including MRIs) on how the traits of neotony, breeding which preserves juvenile qualities such a playfulness, small ears and large eyes, curly tails and colorful coats, and a tendency to imitate behavior, have shaped the modern dog to become man's best workmate and playmate.

Receiving universal rave reviews, Kay Frydenborg's forthcoming A Dog in the Cave: The Wolves Who Made Us Human (Houghton Mifflin Harcourt, 2017) is a real page-turner of narrative nonfiction, with well-presented excursions into paleontology, anthropology, genetics, animal and human medicine, and psychology which open up the fascinating historical quest for what it means to be human... and canine. With photos and factual inserts, backed up by a solid appendix with glossary, chapter notes, a bibliography of books and web resources, and a full index, this book is as absorbing and intriguing as a mystery story, which indeed it is, the continuing mystery of human history and the one species which has lived it with us for tens of thousands of years.

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