Domestication of Dogs: From Wild Wolves to Human Companions

Introduction to Domestication

Domestication represents a process of wild flora and fauna's genetic reorganization into farmed and domestic forms based on human interests. More precisely, domestication denotes the foremost stage of mankind's control over untamed fauna and flora. The chief difference between domesticated fauna and flora and their wild ancestors is that the former are cultivated through human effort to fulfill particular requirements or preferences. Furthermore, domesticated wildlife adjusts to the constant care and attention provided by humans (Encyclopedia Britannica, 2016).

The domestication process has contributed greatly to human and material cultural growth, and has led to the emergence of farming as an exclusive means of plant cultivation and animal rearing. These domesticated flora and fauna then transformed into objects of agrarian activity and underwent extreme transformations, growing into something entirely different from their untamed ancestors (Encyclopedia Britannica, 2016).

Origins and Timeline of Dog Domestication

According to Macdonald and Driscoll (2010), domestication constitutes a markedly human effort. It is an age-old idea that, through the study of human-influenced wildlife, humanity can better understand itself. Thus, human civilizations have devoted substantial time and energy to this cause. While dogs are possibly the very first housetrained animals, the question of where they transformed from wild wolves — and which individual or civilization first successfully domesticated them — has no precise answer, as genetic evidence points to a number of places, including Far Eastern lands, Europe, and the regions in between.

MacDonald, O'Brien, and Driscoll (2009) explain that artificial selection has a unique nature, as it is entirely unnatural. While this fact may seem inconsequential, upon careful reflection one understands precisely how important and remarkable artificial selection — in the form of domestication — has been to our species' success. Only about 12,000 years ago did humanity begin consciously harnessing other life forms' four-billion-year evolutionary heritage; taking advantage of wildlife's genetic diversity accorded humanity a central role in the process of evolution. Animal rearing and agrarian food production enabled humanity to grow in size from roughly ten million Neolithic-age individuals to approximately 6.9 billion today, with the human population continuing to grow exponentially. As of now, 4.93 billion hectares of land are allocated to agriculture — an occupation that utilizes seventy percent of all fresh water resources consumed worldwide. Wildlife species across the globe face a great threat of extinction, 100 to 1,000 times faster than the traditional "background" rate, chiefly due to the loss of natural habitat from its conversion into agricultural land. Human activities have had an immense impact on the earth, on humanity, and on domesticated species, including a near-total transformation of our planet's natural ecosystems. However, no domesticated animal species has, until now, faced the threat of extinction.

Domestication of flora and fauna increased humanity's nutrient and calorie supply, giving rise to a Neolithic Revolution. But this revolution entailed more than mere food production — it also involved the development of an agrarian economy encompassing numerous animals and plants, enabling urban civilization growth and facilitating the innovations we recognize as culture. Much of what we see in the current age indirectly resulted from artificial selection. While ploughs signify the Neolithic age, a look at history from an evolutionary perspective reveals that intelligent alterations to the genetic makeup of specific habitats' flora and fauna actually made such tools possible. Neolithic-era farmers were, in a way, the world's first geneticists, using domestic agriculture as the lever with which they effectively moved the earth (Driscoll, Macdonald, & O'Brien, 2009).

Canid Taxonomy and Ancestral Lineage

The earliest life form domesticated by mankind was the dog. Nevertheless, despite several decades of research, scholarly debate continues regarding the time and place of wolves' transformation into dogs. Naturalist Charles Darwin made the first scientific attempt at tracing dogs' evolutionary origins. In his 1868 work The Variation of Animals and Plants under Domestication, he speculated whether the evolution of dogs resulted from a rare jackal-wolf mating or whether they descended from a single species. After several decades of such speculation, the latter part of the 1990s saw genetic researchers confirm that the ancestors of dogs were gray wolves, as the two species share 99.9% identical DNA. However, the precise time and place of this genetic transition remained unknown. In 1977, excavators working in northern Israel found a human skeleton, traceable to approximately 12,000 years ago, with a puppy in its arms. This finding pointed to dog domestication within the Middle Eastern region just before mankind commenced agricultural activities. However, subsequent excavations of skulls from prehistoric German campsites and Russian caves pushed back the origins of dogs by a further 4,000 years, suggesting that dogs accompanied Eurasians even during their hunting and gathering period (Grimm, 2015).

Present-day wolf-resembling canids make up the genus Lycaon, genus Canis, and genus Cuon, and include dogs, red wolves (Canis rufus), gray wolves (Canis lupus), coyotes (Canis latrans), eastern wolves (Canis lycaon), Ethiopian wolves (Canis simensis), golden jackals (Canis aureus), dholes (Cuon alpinus), African wild dogs (Lycaon pictus), black-backed jackals (Canis mesomelas), and side-striped jackals (Canis adustus). In 1934, a renowned paleontologist proposed that one extinct gray-wolf subspecies was probably the dog's direct ancestor (Frantz, Larson, & Bradley, 2016).