The very first reader query I received after last week's publication of my book "Dog Sense" in the USA was both insightful and thought-provoking. Donald Putnam wrote me ‘Might the "accidental" domestication of dogs have led man to have the idea that we might be able to do the same with the other animals that were domesticated after the dog?'
The domestication of animals was self-evidently a crucial part of the human race's transition from hunter-gatherer through pastoralist, but despite its importance, many unanswered questions remain. Why, for example, have so few species of animals been domesticated? Animal scientists are divided as to whether the primary cause of this is biological (most animals are unsuited to domestication) or cultural (once a species is domesticated, it quickly becomes an intrinsic part of human culture and is therefore unlikely to be supplanted). The spread of cattle through Africa, a species poorly adapted to that continent, especially in terms of resistance to disease, supports the latter. The same applies to the domestic horse, a high-status animal imported to Africa from Europe in the nineteenth century, while the ecologically much better adapted quagga was being hunted to extinction.
The dog was undoubtedly the first animal to become domesticated. From a modern perspective, it seems entirely plausible that the idea of taking other animals out of the wild (using them to stabilise the supply of valuable animal protein - meat, eggs, milk, fur) might have caught on. The archaeological evidence does not support this, however. For example, it seems to have taken a couple of thousand years for the pig to travel from wild animal to full domestication, suggesting an accidental process rather than one inspired by the example of the domestic dogs that were by then ubiquitous.
The gap of several thousand years between the domestication of the dog and the domestication of the first food animals (sheep and goats) was probably too long for the concept of domestication to have survived. Without any written records, and with only an orally transmitted ‘folk biology' to guide them, my guess is that once dogs no longer looked like wolves, their wild origins would have been forgotten. They would have become a part of human society, incapable of inspiring subsequent domestications because their link with the wild had become obscure.
At what point in history did domestication become deliberate? This is hard to tell, but the domestication of the cat, which occurred as recently as 4,000 years ago, may have been an accident of history. Many species of small cat seem to be suitable for domestication, but only the species indigenous to the Fertile Crescent, Felis libyca, happened to be in the right place at the right time and made the jump from wild to domestic.
However, these are just my perspectives as a biologist. Animal domestication is a complex subject, wide open to speculation and addressed by several academic disciplines, though central to none (for a contrasting viewpoint from an anthropologist, see Nerida Russell's article ‘The Wild Side of Animal Domestication'.)