In the past long before our best friend the dog even existed there were wolves. The world of their time was incredibly competitive and often violent. So how did dogs develop and separate from the wolf and become our best friend?
Most scientist believe that Gray Wolves and dogs diverged from an extinct wolf species 15,000 to 40,000 years ago. Brian Hare an evolutionary anthropologist states that what happens next, the domestication of dogs was one of the most extraordinary events in human history.
But there are disagreements as to where are partnership took place. Genetic studies have pinpointed everywhere from “Southern China”, “Mongolia” to “Europe”.
There is also plenty of scientific disagreement as to the timing of when this partnership took place. There is research in “Nature Communications” that pushes the dates of back to where domestication took place just once at least 20,000 but probably more like 40,000 years ago. Krishna R. Veeramah an evolutionary ecologist and colleagues sampled DNA from two Neolithic German dog fossils, 7,000 and 4,700 years old respectively. Tracing genetic mutation rates in these genomes yielded the new estimates.
Dr. Veeramah has found that our ancient dogs from the same time period were very similar to modern European dogs, including the majority of breed dogs people keep as pets.
There is now a study that suggests that dogs could have been domesticated more than once. Researchers analyzed mitochondrial DNA sequences from the remains of 59 European dogs (aged 3,000 to 14,000 years). and the full genome of a 4,800-year-old dog that was buried beneath the “Prehistoric Mound Monument” of Newgrange, Ireland.
Comparing these genomes with many wolves and modern dog breeds suggested that dogs were domesticated in Asia, at least 14,000 years ago, and their lineages split some 14,000 to 6,400 years ago into East Asian and Western Eurasian dogs.
But there are dog fossils apparently older than these dates that have been found in Europe, scientists theorize that wolves may have been domesticated twice, though the European branch didn’t survive to contribute much to today’s dogs. Gregar Larson, director of the Wellcome Trust Palaeogenomics & Bio-Archaeology Research Network at Oxford University, suggests that the presence of older fossils in both Europe and Asia, and the lack of dogs older than 8,000 years in between those regions, supports such a view.
“Our ancient DNA evidence, combined with the archaeological record of early dogs, suggests that we need to reconsider the number of times dogs were domesticated independently. Maybe the reason hasn’t yet been a consensus about where dogs were domesticated is because everyone has been a little bit right,’ Larson said. Also the many interbreedings of dogs and wolves also cloud the genetic waters and such events still happen today.
Maybe even more intriguing then where and when dogs became domesticated is how that happened. Was it really like how it happened in the movie “Alpha” of a hunter helping an injured wolf?
Another theory is that maybe early humans captured wolf pups, kept them as pets, and gradually domesticated them. This could have happened around the same time as the beginning of agriculture, about 10,000 years ago. The oldest fossils generally agreed to be domesticated dogs date back about 14,000 years, but there is disputed fossil evidence that date back more than twice that age which could also be dogs.
There are also genetic studies that suggest that the date of domestication occurred far earlier, and a different theory has gaining the support of many scientists is that wolves largely domesticated themselves among hunter-gatherer people.
Brian Hare said “That the first domesticated animal was a large carnivore, who would have been a competitor for food-anyone who has spent time with wild wolves would see how unlikely it was that we somehow tamed them in a way that let to domestication”.
But Hare also notes, the physical changes that appeared in dogs over time, including splotchy coats, curly tails, and floppy ears, follow al pattern of a process known as self-domestication. It’s what happens when the friendliest animals of a species somehow gain an advantage. Friendliness somehow drives these physical changes, which can begin to appear as visible by-products of this selection in only a few generations.
He also states that most wolves would have been fearful and aggressive towards humans-because that’s the way most wolves behave. But some would have been friendlier, which may have given them access to human hunter-gatherer foods.
The friendlier wolves would have had an advantage over other wolves, and the strong selection pressure on friendliness had a lot of by-products, like the physical differences we see in dogs. So this is what is called self-domestication. We didn’t domesticate dogs. Dogs domesticated themselves.
This is interesting. There is a study that provided some possible genetic support for this theory. Evolutionary biologist Bridgette von Holdt, of Prineton University, and colleagues suggest that hypersocial behavior may have linked our two species and zero in on a few genes that may drive that behavior.
Generally dogs display a higher level of motivation than wolves to seek out prolonged interactions with humans, she says.
Von Holdt’s research shows that the social dogs she tested have disruption to a genomic region that remains intact in more aloof wolves. Interestingly, in humans genetic variation in the same stretch of DNA causes Williams-Beuren syndrome, a condition characterized by exceptionally trusting and friendly behaviors.
The results suggest that random variations to these genes, with others yet unknown, may have played a role in causing some dogs to first cozy up with humans.
HAVE DOGS CHANGED SINCE BECOMING OUR BEST FRIEND?
There is still lots to learn about the origins of dog/human partnership. But it’s becoming increasingly clear that each species has changed during our long years together. Taken that the physical differences between a basset hound and a wolf are obvious, dogs have also changed in ways that are more akin to us.
One study has shown that by bonding with us and learning to work together with humans, dogs may have actually become worse at working together as a species. Their pack lifestyle and mentality appear to be reduced and is far less prevalent even in wild dogs than it is in wolves. But it seems that dogs may have compensated for this in other ways. They’ve learned to use humans to solve their problems.
“Several researchers have presented dogs and wolves with an impossible problem (e.g., puzzle box that can’t be opened or a pulling tool that stops working) and have asked how these different species react. And what has been found is that wolves try lots of different trial and error tactics to solve the problem-they get at it physically. But at the first sign of trouble, dogs do something different. They look back to their human partner for help. This work hints that dogs may have lost some of their physical problem-solving abilities in favor of more social strategies, ones that rely on the unique sort of cooperation domesticated dogs have with humans. This also matches the work showing that dogs are especially good at using human social cues.”
It even seems that our relationship has become so close that even our brains are in sync. There is a study that shows that dogs hijack the human brain’s maternal bonding system. When humans and dogs look with affection into one another’s eyes, each of their brains secretes oxytocin, a hormone linked to maternal bonding and trust. Other mammal relationships, including those between a mom and child, or between mates, feature oxytocin bonding, but the human/dog example is the only case in which it has been observed at work between two different species.
The true story of how humans and dogs bonded may never be completely known. But dogs have without doubt helped us in countless ways over the years. Still, only now may we be realizing that by studying them, they can help us better understand ourselves.