Dogs are the most revered household pet. Ranging in all facets of size coupled with a loyalty that stands the test of time, dogs easily take the face for the American household animal. Yet the exact origins of this most adored animal generates a dog fight between biologists who hold differing breeds of thought. In one corner stands the idea that dogs were domesticated in an agricultural setting. In the other corner stands the idea that dogs were domesticated by hunter-gatherers. Yet in all facets of life, there exists multiple shades of gray between an opposing spectrum. Since the dogs evolution is muddled by genetic rift and interbreeding, it is difficult to pinpoint the precise origins of dogs.
A recent study published in PLOS Genetics gives credence to the view that dogs were domesticated by hunter- gatherers approximately 11,000 to 16,000 years ago. Traditionally, the lineage of dogs could be classified by comparing the proportions of their distinct nasal cavities and skulls. In biology, the classification of organisms in accordance to their features is known as taxonomy. It is one way that Charles Darwin illustrated that all animals share a common ancestor in the Origin of Species. Yet the diagrams provided by taxonomy have been cross-confirmed by a more recent and advanced field of biology known as molecular genetics.
By unraveling the dogs genome, the team of researchers looked for clues regarding the dogs precise origins. The scientists examined the genome of two dog breeds; the dingo from Australia and the Basenji whose origins trace back to Africa. The researchers also examined the genomes of three distinct wolves living in separate regions including Israel, Coratia and China. The wolves were selected on the grounds that each lived in a location that was a top candidate for the exact origins of dogs.
The difficulty is that the dogs evolution is muddled by genetic rift. In particular, dogs and wolves have been interbreeding and swapping genetic traits in recent times. Due to this, it is difficult to determine whether dogs are descended from wolves, or whether wolves and dogs both evolved from a common ancestor. Through careful genetic analysis, the team of researchers concluded the latter is more likely the case. In particular, researchers concluded that dogs and wolves co-evolved from a more ancient ancestor that is now extinct. More specifically, however, unraveling the genome of the dog gave biologists positive reasons for thinking that dogs were domesticated by hunter-gatherers.
The researchers discovered that most dogs have a greater amount of amylase genes than most wolves. Amylase genes are essential to efficiently digesting starch. The idea is that dogs originally lived in a terrain in close proximity to agricultural settlements. Due to environmental pressures, dogs gradually adapted to consume agricultural waste.
Although the dogs evolution is muddled by genetic rift, the insights of the study can help clear the air. Understanding where these creatures first evolved can help strengthen the future of our domestic relation, such as determining a proper diet for dogs as well as healthy breeding sizes.
By Nathan Cranford