The friendship and affinity of dogs to humans are obvious to all. Unlike cats, dogs are not only the best friend of humans, but also make very important contributions to humans. Because dogs are so important, people are also very curious about figuring out the origin of this friend.
In fact, domestic dogs belong to the same family as animals such as wolves, foxes, jackals and wild hunting dogs. Their common name is Canidae. Real canines first appeared 5 million to 7 million years ago. It began to walk with four toes (the fifth toe gradually degenerates into residual toes), and the toes are relatively close, which is a very suitable structure for hunting.
Since the Darwinian era, people have been debating endlessly about the origin of domestic dogs. Darwin is more pessimistic on this issue. He believes that "the origin of most domestic animals may be forever ambiguous." The diversity of dogs is so obvious that Darwin tends to think that the ancestors of dogs are likely to be jackals, because jackals are also very obvious.
No domestic animal has an exaggerated diversity in appearance and temperament as exaggerated as a dog. It is incredible to think about the huge difference between a ferocious Tibetan mastiff and a docile pug, and they are actually the same species. So much so that for a long time, it was believed that dogs must have originated from several canine species. About 100 years after Darwin's Origin of Species was published, Watson and Crick discovered the double helix structure of DNA, thus finally establishing that DNA is the genetic material that has been searching for for a long time. With DNA, there are new and more reliable methods to find the origin of species.
In 1997, UCLA scientists were the first to use mitochondrial DNA to trace dogs’ ancestors, comparing mitochondrial DNA from 140 different species of dogs, 162 gray wolves, 5 North American little wolves and 12 jackals from all over the world. Research shows that dogs have a close relationship with gray wolf, which means that dogs are most likely to come from human domestication of gray wolf.
In 2003, researchers at the Fred Hutchson Cancer Research Center in Seattle, USA reported in the American Journal of Science that they analyzed the genes of 414 purebred dogs in 85 breeds, compared them with each other and with wolf genes, and came up with some results. Genes are very similar between dogs of a particular breed, and there are certain differences in genes of dogs of different breeds. This difference is like the difference between people of different races. Although 99% of the genes in all dogs are the same, the remaining 1% of the genetic differences determine the breed of dogs.
So, this is roughly the source of dogs. Although the later domestication process may be very difficult, it is indeed a very successful pet choice now.