A recent NOVA special entitled Dogs Decoded (available on Netflix) provides remarkable evidence of dogs’ incredible intelligence and demonstrates how they bond with humans in ways their ancestors, wolves, cannot. It also provides yet another reason to believe in the work of a divine Creator.
Highlights from the special
Dogs and humans bond with each other in several ways. For example, research indicates that man’s best friend possesses the ability to read human expressions uniquely from other animals. For instance, dogs can readily follow human signals, such as hand or eye movements, that chimpanzees cannot. Yet dogs do not respond to similar signals from other dogs or animals, only from humans. Increasing evidence also indicates that dogs may even be able to read human emotions. Research shows that bonding moments occur when dogs and humans both experience a release of the hormone oxytocin during a petting session. (This is the same hormone released by a human mother while breastfeeding.)
Based on DNA comparisons, dogs are genetically indistinguishable from gray wolves. However, in the process of domestication, breeds have become as diverse as the Pekingese and the Great Dane. The documentary points out that—in addition to providing companionship—domesticated dogs have helped humans hunt and herd for thousands of years, helping advance civilization greatly.
Since dogs and wolves are genetically identical, researchers in Hungary raised litters of wolf cubs and dog puppies side by side to see if the grown wolves would act like dogs. At eight weeks of age, the wolves began to show aggressive tendencies. Whereas the puppies would engage with people, the wolf cubs began to act as they would in the wild. After four months, the wolves became too vicious and had to be released.
Meanwhile, an experiment, begun in the Soviet Union near Novosibirsk in 1959 and still ongoing, has resulted in the successful domestication of silver foxes. The researchers noted that most first generation foxes showed aggression or fear. Only about one percent showed neither. This one percent became the founding generation for a new breed. The selection process was repeated and in just three generations aggressive behavior began to disappear. By the eighth generation, foxes began to seek contact with and show affection to humans. After fifty years, the foxes are tamer than ever. Aggressiveness appears to be a genetic trait, with tamer foxes producing less adrenaline than their aggressive counterparts. The research revealed another startling development: as foxes become tame, coat pattern and color begins to change and some animals develop curly tails and floppy ears. In other words, they begin to look more like dogs than foxes.
What conclusions can we draw from these observations?
First, the NOVA special suggests a scenario for how dogs might have been domesticated originally. Perhaps a human hunter in some prehistoric era discovered a litter of young orphaned wolf cubs and attempted to raise them. Initially, such a project would likely have been unsuccessful because of the cubs’ ferocity, but some people would have persisted. Eventually one non-aggressive, non-fearful cub would have survived to adulthood. After many similar projects, a pair of full-grown, non-aggressive, non-fearful wolves would have mated, and within several generations their tame offspring would have become the first domesticated dogs. In fact, recent research suggests that the domestication of wolves may have occurred at least 50 times within the past 16,300 years in China.1
Second, since wolves and foxes are natural carnivores and hunters, aggressiveness and fear should be genetic traits favored by natural selection. In fact, it seems that lacking these traits would become a disadvantage and most likely be eliminated by natural processes. Thus, it is not surprising that 99 percent of wild foxes in the beginning of the Russian experiment showed aggression and fear toward their human handlers. But wolves and foxes sometimes perform a secondary role as scavengers. The existence of a small number displaying neither aggressiveness nor fear may at least be partially consistent with this role and may help explain why these characteristics did not disappear long before dogs were domesticated.
Finally, can natural selection explain the traits allowing foxes (and presumably wolves) to become domesticated and bonded with humans? As the special indicates, some 40 generations of wild foxes were selectively bred to interact with humans in ways similar to dogs and their puppies.2 These interactions appear inconsistent with the concept of natural selection and the animals’ expected roles as carnivores, hunters, or scavengers. Indeed, such traits do not seem consistent with any reasonable role for an animal attempting to survive in the wild. I would argue that these traits in the fox (and most likely the wolf) genome can be readily explained if they were placed there by a Designer who desired to create an animal that would not only help humans survive, but also provide cherished companionship.
Mr. Kirby Hansen received his MS in Communications Engineering from Naval Postgraduate School and his MBA from the Stanford Graduate School of Business.
- Jun-Feng Pang et al., “mtDNA Data Indicate a Single Origin for Dogs South of
Yangtze River, Less than 16,300 Years Ago, from Numerous Wolves,” Molecular Biology and
Evolution 26, no. 12, (December 2009): 2849–64.
- For further details on the Russian experiment with silver foxes, see Anna V. Kukekova et al., “The Genetics of Domesticated Behavior in Canids: What can Dogs and Silver Foxes Tell Us about Each Other?,” in The Dog and its Genome, ed. Elaine A. Ostrander, Urs Giger, and Kerstin Lindblad-Toh, vol. 44 in Cold Spring Harbor Monograph Series (Woodbury, NY: Cold Spring Harbor Laboratory Press, 2005), 515–37.