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How Did Wolves Evolve into Man's Best Friend?

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By Chris Gayomali

Implausible as it may seem, your harmless little maltipoo puppy descended from a fearsome line of bloodthirsty wolves. And thanks to a new discovery, scientists now have a better idea of how exactly that happened.

Comparing dog and wolf DNA, new research published inNature suggests that dogs possess an evolved set of genes that help them more effectively break down carbs and starches than their ferocious, wild ancestors. It's why our cuddly pals are more likely to go for a dog biscuit than, well, our throats. 

Combing through the genomes of 60 domestic breeds — including golden retrievers and cocker spaniels — Swedish researchers discovered that dogs have a much easier time converting starches into glucose than modern wolves. This means that at some point in dogs' evolutionary history, packs of wild canids struck up a mutually beneficial relationship with early humans, and learned to subsist on people food — stuff like wheat, barley, corn, rice, and potatoes. In exchange, man earned himself a loyal friend and fierce protector.  

"I think it is a striking case of co-evolution," Erik Axelsson, a geneticist at Uppsala University, tells the Washington Post. "The fact that we shared a similar environment in the last 10,000 years caused a similar adaptation. And the big change in the environment was the development of agriculture."

But why did dogs and humans start hanging out in the first place? That's still a matter of contention. Some researchers think that early humans domesticated wolves they found skulking through the trash in village outskirts. Others think humans captured and raised wolf puppies early in their lives and that over time they and their offspring became tame. 

Mark Derr, author of How the Dog Became the Dog, thinks wolves started following man around when our ancestors were still nomadic. The theory goes that wolves realized that these weapon-toting, bipedal hunters were very effective killing machines, and began following them, taking whatever scraps were left over from a big kill. (Scavenging consumes less energy than hunting, the thinking goes.) Eventually, a relationship was established, and these furry creatures began to travel with us, evolving smaller skeletal frames and shorter jaws over the centuries. 

"You had populations of dog-wolves that became isolated, and in doing so, they began to inbreed," Derr tells NPR. "And when you inbreed, you get genetic peculiarities that arise, and then those peculiarities become part of the population. If they work or become popular or have some function of beauty or utility, then they were kept by the humans — and that population then spreads those through other populations through breeding."

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Animals
Owning a Dog May Add Years to Your Life, Study Shows
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We've said that having a furry friend can reduce depression, promote better sleep, and encourage more exercise. Now, research has indicated that caring for a canine might actually extend your lifespan.

Previous studies have shown that dog owners have an innate sense of comfort and increased well-being. A new paper published in Scientific Reports and conducted by Uppsala University in Sweden looked at the health records of 3.4 million of the country's residents. These records typically include personal data like marital status and whether the individual owns a pet. Researchers got additional insight from a national dog registry providing ownership information. According to the study, those with a dog for a housemate were less likely to die from cardiovascular disease or any other cause during the study's 12-year duration.

The study included adults 40 to 80 years old, with a mean age of 57. Researchers found that dogs were a positive predictor in health, particularly among singles. Those who had one were 33 percent less likely to die early than those who did not. Authors didn't conclude the exact reason behind the correlation: It could be active people are more likely to own dogs, that dogs promoted more activity, or that psychological factors like lowered incidences of depression might bolster overall well-being. Either way, having a pooch in your life could mean living a longer one.

[h/t Bloomberg]

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Big Questions
Why Don't We Eat Turkey Tails?
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Turkey sandwiches. Turkey soup. Roasted turkey. This year, Americans will consume roughly 245 million birds, with 46 million being prepared and presented on Thanksgiving. What we don’t eat will be repurposed into leftovers.

But there’s one part of the turkey that virtually no family will have on their table: the tail.

Despite our country’s obsession with fattening, dissecting, and searing turkeys, we almost inevitably pass up the fat-infused rear portion. According to Michael Carolan, professor of sociology and associate dean for research at the College for Liberal Arts at Colorado State University, that may have something to do with how Americans have traditionally perceived turkeys. Consumption was rare prior to World War II. When the birds were readily available, there was no demand for the tail because it had never been offered in the first place.

"Tails did and do not fit into what has become our culinary fascination with white meat," Carolan tells Mental Floss. "But also from a marketing [and] processor standpoint, if the consumer was just going to throw the tail away, or will not miss it if it was omitted, [suppliers] saw an opportunity to make additional money."

Indeed, the fact that Americans didn't have a taste for tail didn't prevent the poultry industry from moving on. Tails were being routed to Pacific Island consumers in the 1950s. Rich in protein and fat—a turkey tail is really a gland that produces oil used for grooming—suppliers were able to make use of the unwanted portion. And once consumers were exposed to it, they couldn't get enough.

“By 2007,” according to Carolan, “the average Samoan was consuming more than 44 pounds of turkey tails every year.” Perhaps not coincidentally, Samoans also have alarmingly high obesity rates of 75 percent. In an effort to stave off contributing factors, importing tails to the Islands was banned from 2007 until 2013, when it was argued that doing so violated World Trade Organization rules.

With tradition going hand-in-hand with commerce, poultry suppliers don’t really have a reason to try and change domestic consumer appetites for the tails. In preparing his research into the missing treat, Carolan says he had to search high and low before finally finding a source of tails at a Whole Foods that was about to discard them. "[You] can't expect the food to be accepted if people can't even find the piece!"

Unless the meat industry mounts a major campaign to shift American tastes, Thanksgiving will once again be filled with turkeys missing one of their juicier body parts.

Have you got a Big Question you'd like us to answer? If so, let us know by emailing us at bigquestions@mentalfloss.com.

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