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The dog was domesticated once from the lost wolves



Close up of dog's face.

Genomics researcher Anders Bergstrom and his colleagues recently sequenced the genomes of 27 dogs at archaeological sites in Europe and Asia. They ranged in age from 4,000 to 11,000 years. These genomes, as well as the genomes of modern dogs and wolves, show how dogs have moved around the world with people since they were domesticated.

All the dogs in this study came from the same common ancestor, but the primitive dog population split into at least five branches as it expanded in different directions. When a group of people dispersed, moved and met other groups of people, they brought their dogs. The DNA of dogs indicates that their population history largely reflects the story of humans.

Bergstrom of the Francis Crick Institute said in a statement: “Knowing the history of dogs can not only tell us their history, but also our history.”

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We still don’t know who let the dog go

We still don’t know the exact time or when dog domestication first occurred. By 11,000 years ago, its history was quite complicated. But it seems that it only happened once. The ancient genome shows that dogs all have a common ancestor, while modern wolves do not. According to Bergstrom and his colleagues, this probably means that the dogs are all from a group of wolves, and that group is now extinct.

In the research, the modern gray wolf does not seem to be very closely related to any ancient or modern dog. This shows that since domestication has made them unique, wolves have not contributed much to the canine lineage.

The oldest dog in the study lived with Mesolithic hunter-gatherers, about 10,900 years ago, in what is now Sweden. Its DNA indicates that most of its ancestors came from the eastern branch of the Canidae tree, which gave birth to Siberian dogs, native North American dogs, and even New Guinea singing dogs and Australian wild dogs.

But certain bloodlines of dogs also come from the branch that followed humans into the Levant and Southwest Asia. When the dog’s ancestors meet another group of dogs, the DNA may be used as a souvenir. In other words, by 11,000 years ago, dogs had had time to become a species, split into different populations as they separated, and then met again and exchanged DNA.

Have a dog, can travel

Bergstrom and his colleagues wanted to know how the dog population history aligns with the human population history. They compared their ancient dog data with what ancient human DNA told us about how a group of people moved and interacted over the past 12,000 years. Not surprisingly, the timing of splits, mergers, and changes are mostly matched. This shows that as a group of people move, they take their dogs with them, and when people meet new neighbors, dogs play a similar role to humans.

The ancient human genes tell us that it took several centuries for the early farmers to migrate north and west from Turkey to Europe from what is now Turkey about 8,000 years ago.

“It is not yet clear how these movements occurred-whether due to disease, violence, or prejudiced intermarriage-but genetics clearly shows that these changes did happen, and more than any archaeologist expected. Dramatic,” The Empire returns to 2018.

The DNA of ancient European dogs tells us that very similar things happened between the dogs of the newcomers of the Neolithic Age and the dogs that already existed (such as the 11,000-year-old Swedish dog mentioned above). Generally speaking, dogs found at archaeological sites in Northern and Western Europe have more Eastern ancestry and less Levantine ancestry than those found in the South and East, and vice versa.

Some dogs use very long leashes

The dog story and the human story coincide at least in broad aspects. But Bergstrom and his colleagues discovered that some dog stories seem to be “out of touch” with our views. These differences may be the result of illness, trade, preference for specific dog types, or people moving to new places without their dogs (to be honest, this sounds bad). These “decoupled” population histories can tell us how dogs adapted to ancient human society.

Thousands of years after the Neolithic occupation of Europe, another group of people swept westward from Central Asia. They may have brought dogs like dogs, which are 3800-year-old animals found in archaeological sites in the Russian steppes.

But even though herders from the grasslands added their DNA to the people that make up the modern European population, their dogs do not seem to be mixed with local dogs. At the same time, in China, the situation is just the opposite. Grassland herders expanded eastward, but modern people in East Asia carried very little DNA. However, modern East Asian dogs have gained considerable pedigree from dogs such as the 3800-year-old Srubnaya.

“Perhaps there are sometimes opportunities in these processes, so if we can replay many records of human history, the results for dogs may not always be the same,” Bergstrom told Als.

Old dog and new genome

Part of the reason why the earliest domestication of dogs is so vague (not sorry) is that the DNA of ancient dogs is very scarce. Until recent research, scientists have only published six prehistoric dog and wolf genomes. If you keep the score, so far, we have sequenced more Neandertal genomes than prehistoric dog genomes.

Bergstrom told Ars: “Ancient DNA is still a young field. For most animals, there hasn’t been much research on the whole genome. In order for him and his colleagues to add 27 ancient dog genomes to In this list, archaeologists and museum curators have made international efforts. The collaborators found the remains of ancient dogs in the collections of museums and universities and on the list of materials excavated at the archaeological site.

According to Bergstrom, more ancient dog genomes, as well as more archaeological evidence about how dogs adapted to ancient culture and economy, can help us understand the origin of dogs and parts of our history that don’t seem to be connected.

Perhaps one day, we will even learn the answers to all the most pressing questions: “Who is a good dog?”

science, 2020 DOI: 10.1126/science.aba9572 (about DOI).


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