Science

Different Breeds of Dogs Existed by End of Last Ice Age, Study Finds

Research shows that our best friend might be our oldest one too.
October 30, 2020, 10:19am
dogs ice age DNA
Photo courtesy of Jonatan Burneo via Unsplash

According to a study published in the Journal Science, our canine companions were already present at the end of the last Ice Age, and their legacy continues in our pets today. 

The study revealed that the domestication of dogs can be traced back 800 to 11,000 years old. It further confirms that dogs were domesticated before any other species. 

“[If] I walk through Wimbledon Common I am pretty likely to run across dogs that all have a little bit [of a] different history, tracing back as far as 11,000 years ago to different corners of the world,” said Pontus Skoglund, co-author of the study and group leader of the ancient genomics laboratory at the Francis Crick Institute in London.

The analysis also reveals that there were genetically at least five distinct groups of dogs in existence by the end of the Ice Age, which means the origin of dogs stretches back even further. It was also noted that all the groups appeared to have descended from a single common ancestor. 

"Dogs are really unique in being this quite strange thing if you think about it, when all people were still hunter gatherers, they domesticated what is really a wild carnivore—wolves are pretty frightening in many parts of the world,”  said Skoglund to BBC News.. “The question of why did people do that? How did that come about? That's what we're ultimately interested in.", 

The researchers further revealed that when the DNA from modern dogs was compared with their results, it was found out that breeds that originated in Europe (such as Irish terrier or German shepherd) mostly appear to be descended from a mix of two ancient groups from the Levant and northern Europe.

“Those ancestries came together in Europe, probably when the first farmers came into Europe and they brought their dogs and they met the dogs that were already there,” said Skoglund to The Guardian. “Breeds in Europe today are less genetically distinct than the two in prehistory, in that they have a less deep history that doesn’t stretch back thousands of years”. 

A team of international researchers analysed the whole genomes that is the full complement of DNA in the nuclei of biological cells of 27 different ancient remains of dogs that were associated with different varieties of archaeological cultures. 

The samples were compared to each other and to modern dogs and the results revealed that breeds like Rhodesian Ridgeback in southern Africa and the Chihuahua and Xoloitzcuintli in Mexico showed genetic traces of ancient indigenous dogs from the particular region. Chinese breeds seem to have derived some of their ancestry from animals like the Australian dingo and New Guinea singing dog, and the rest from Europe or dogs from the Russian steppe.

It is also noted that the genetic pattern of dogs is very similar to humans because everytime people moved, they took their animal companions with them. But there are differences too. 

For instance, if we look at the early European dogs, they were initially diverse and it seemed to originate from two very different populations, one related to Near Eastern dogs and another to Siberian dogs.

But it is believed that after the onset of the Bronze Age, a single dog lineage spread widely and replaced all other dog populations on the continent. It has no counterpart in the genetic genetic patterns of people from Europe. “If we look back more than four or five thousand years ago, we can see that Europe was a very diverse place when it came to dogs. Although the European dogs we see today come in such an extraordinary array of shapes and forms, genetically they derive from only a very narrow subset of the diversity that used to exist”, said Anders Bergström, lead author and post-doctoral researcher at the Crick. 

Dogs, our oldest and closest animal partners, are believed to have evolved from wolves that moved with humans. As they were tamed, they served humans as guards. It also suggests that they might have derived from a single extinct wolf population or very closely related ones. 

On the other hand, animals like cats became our pets when humans started to settle down to farms around 6,000 years ago. Cats were useful for controlling pests such as mice and were also attracted by waste generated by dense settlements, and this was one of the reasons for their domestication. 

"Dog history has been so dynamic that you can't really count on it still being there to readily read in their DNA,” said Skoglund. “We really don't know—that's the fascinating thing about it.”

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