How Dogs depart from being like Wolves

[lpetrich]

In their domestication, dogs acquired features that distinguish them from the wolves that were their ancestors.

Some features are shared by other domestic animals.  Domestication of animals Domestication syndrome: Why all domesticated animals look alike - Big Think An important change is tameness, and that involves less adrenalin production. But common ways of reducing adrenalin apparently have side effects like floppy ears and white spots. This is evident in dogs and cats and cows and horses and even in Dmitry Belyayev's domesticated Siberian foxes.

Domestic animals also sometimes have shorter snouts, rounder heads, and smaller brains than their wild ancestors. The shorter snouts and rounder heads makes them look more humanlike, including more babylike.

But dogs also have some additional adaptations to domesticity.

Dogs Evolved Sad Eyes to Manipulate Their Human Companions, Study Suggests
Why Do Dogs Look So Sad? - The Atlantic - "Dogs’ Eyes Have Changed Since Humans Befriended Them. Two specialized muscles give them a range of expression that wolves’ eyes lack." - Evolution of facial muscle anatomy in dogs | PNAS

These are muscles around their eyes, and dogs can use them to look sad by human standards.

By Domesticating Dogs, Humans May Have Ruined Their Wolf-Pack Instincts - The Atlantic - "Wolves dramatically outperform pooches at a task that requires them to work together." - Importance of a species’ socioecology: Wolves outperform dogs in a conspecific cooperation task | PNAS

Sarah Marshall-Pescini, from the University of Vienna, has now found that dogs are terrible at a simple task that requires them to cooperate. Working together, they have to pull on two pieces of rope to bring a piece of distant food within reach—and they mostly fail. Wolves, however, are far more successful, dramatically outperforming their domestic peers.

What are you looking at? Dogs are able to follow human gaze -- ScienceDaily
Dogs are able to follow human gaze
Dogs Follow the Gaze of Humans, Especially When There’s Food Involved - Scientific American Blog Network
The Science of Animal Behavior and Cognition
Training for eye contact modulates gaze following in dogs - ScienceDirect

Starchy Diets May Have Given Ancient Dogs a Paw Up

According to new genetic research, domestic dogs' genomes better equip them to handle starches than wolves. Domestic dogs also show differences from wolves in portions of the genome linked to brain development, perhaps hinting at behavioral changes that occurred as canines became less wild.

The findings are particularly fascinating given that humans who live off farmed foods show similar genetic changes as dogs compared with humans who survive mostly by hunting and gathering, said study researcher Erik Axelsson of the department of medical biochemistry and microbiology at Uppsala University in Sweden.

The researchers compared the genes of 12 individual wolves to 60 individual dogs from 14 breeds.

The researchers found that dogs have more copies of a gene called AMY2B, crucial for amylase production, than wolves. And in dogs, this gene is 28 times more active in the pancreas than in wolves.

Dogs also showed changes in specific genes that allow for the breakdown of maltose into glucose, another key starch digestion step, and in genes allowing for the body to make use of this glucose.

So they can digest starchy foods much better, and eat more of what their masters eat.

 

[4321lynx]

Yes, but the "effects" may have been underlying causes for domestication in the distant ancestors. Or not?

 

[steve_bank]

Both feral dogs and cats revert to their genetic history.

Cats become small feline hunters. Females form groups. Males kill offspring. All like the big cats.

Dogs form packs with an alpha male.

 

[Trausti]

Evolution happens fast.

Evolution of facial muscle anatomy in dogs

Dogs were shaped during the course of domestication both in their behavior and in their anatomical features. Here we show that domestication transformed the facial muscle anatomy of dogs specifically for facial communication with humans. A muscle responsible for raising the inner eyebrow intensely is uniformly present in dogs but not in wolves. Behavioral data show that dogs also produce the eyebrow movement significantly more often and with higher intensity than wolves do, with highest-intensity movements produced exclusively by dogs. Interestingly, this movement increases paedomorphism and resembles an expression humans produce when sad, so its production in dogs may trigger a nurturing response. We hypothesize that dogs’ expressive eyebrows are the result of selection based on humans’ preferences.

 

[steve_bank]

Saw a show that talked about some dogs having muscles around the eyes that allow what appears to be an expression, which wolves can not do.