Image credits: Pixabay
Humans have evolution to thank for their dogs and the happiness they derive from playing with their pawed friends. It is unclear when exactly in history did the evolution from wolf to dog happened, but you sure are glad it did, aren’t you? There is evidence of domesticated dogs buried with humans about 15,000 years ago. Some of these remains may even go as further as 36,000 years.
There are many evolutionary theories of how the dog came to be domesticated. A study by geneticists from Uppsala University in Sweden compared DNA from wolves and dogs to see how each are able to adapt to a starchy diet, leading to a broader conclusion of the domestication of dogs.
The study compared the DNA of wolves and dogs and highlighted the differences in their genomes that may have led to their different evolutionary path. The most surprising difference the team found were those involving the digestion of starch. Dogs had a higher number of genes for Amylase (AMY2B), a salivary enzyme that aids in the breakdown of starch compared to wolves. Where wolves had only two copies of the gene, dogs had anywhere between four and thirty. This meant that dogs could digest starch-rich foods better than wolves.
Dogs are carnivorous, despite their omnivorous food habits. Their teeth, manner of chewing, ancestry, and general biology are indicative of their carnivorous roots. The presence of Amylase in such a high number gave rise to a few theories of the dog’s domestication. One theory put forward by geneticist Erik Axelsson is that as wolves began to settle with humans they gradually started developing similar eating habits as their humans.
Early domesticated dogs were primarily carnivorous because their humans were hunter-gatherers. When humans took to agriculture and moved on to a more carbohydrate-based diet, the dogs too evolved simultaneously. Rather than hunt the natural way, dogs were able to gather food from farmland waste dumps. This ensured their digestion of starch-based food was much more efficient than that of their wilder cousins.
This co-evolution of humans and dogs also enabled them to adapt a milder and domesticated behavior. As agriculture flourished, hunting was no longer a necessity, enabling both to develop a tolerance for plant-based nutrition. Agriculture as a reason for the evolution of the dog’s diet is supported by the fact that breeds associated with hunting such as the Siberian Husky have about four copies of the AMY2B gene and those associated with farming have about 30 copies.
It is difficult to pinpoint the exact reason for the domestication of dogs but the research provides a number of opportunities to study the evolution of dogs and wolves. For now, it is safe to say, from this research, that diet may have played a significant role in the domestication of dogs.