DNA analysis shows domestication, selective breeding shaping behavior from 12,000 years ago
Canine genes shaped by human interplay: study
NEW YORK In the genetic journey from wolf to lap dog, dogs developed a unique genius for sensing human intentions, as the interplay of handler and hound shaped the biology of canine behavior in ways that scientists only now are beginning to understand, new research shows.
Dogs are tailored to fit the human mind, like a glove to the hand.
From birth, dogs are fluent in the human text of hand gestures and facial expressions. They can understand humans better than chimpanzees humanity's closest relative or the gray wolves from which dogs are descended, according to the first direct comparison of the species.
Harvard University anthropologist Brian Hare, who conducted the comparison, is publishing his experiments Friday in the journal Science.
This unusual canine social skill does not come from training or experience; nor is it the legacy of a pack species with its own rich vocabulary of body language, Hare said. It arises from genes shaped by human contact, inherited by every contemporary canine, his experiments suggest.
"We have created the dog in our own image," said developmental geneticist Jasper Rine at the University of California at Berkeley.
Through a series of research papers in Science, three independent teams of scientists, including Hare, explored the evolution of dogs from feral scavengers into man's best friend to better understand one of humanity's earliest innovations: the domestication of animals.
By analyzing canine DNA from around the world, the researchers determined that the domestication of dogs was an inspiration that swept the ancient world more quickly and more recently than previously believed. Every one of nearly 400 breeds today descended originally from just five female wolves in East Asia, scientists said.
As perhaps the first wild animal to fall under human sway, dogs offer an unusually clear window into how genes and selective breeding can shape behavior. People have manipulated virtually every aspect of canine design and demeanor, culling for those traits that humans deem most useful in these cold-nosed companions.
Dogs trace their ancestry to primordial wolves that thrived about a million years ago, said Xaoming Wang, an expert on vertebrate paleontology at the Los Angeles County Museum of Natural History. In all, there are 35 canine species alive today, only one of which the domestic dog is the object of human affection.
The earliest fossil evidence of this special relationship was unearthed from a grave in Israel, dating from about 12,000 years ago. In its left hand, the human skeleton cradled a pup.