This is a good opportunity to educate the general [HN] community about dogs:<p>1. They can only see blue/yellow. Not like humans' RGB.<p>2. They are short sighted. For far away objects, their sight is like a T-Rex, they can see moving objects, not stationary objects. Remain still, and they can't see you. Then again, they can smell you, especially if it's downwind.<p>3. Their flicker fusion threshold is higher than humans. If you show them a cute mobile picture of a baby, they'll see a lot of flickering. As well, did you know lights have a flicker? If you think it's bad, it's even worse for dogs which can lead to stress.<p>More:<p><a href="https://dog-vision.com/" rel="nofollow">https://dog-vision.com/</a><p><a href="https://www.dogwalkersmelbourne.com.au/articles-dog-walking-pet-sitting/66-dog-canine-vision-seeing-compare-human.html" rel="nofollow">https://www.dogwalkersmelbourne.com.au/articles-dog-walking-...</a>
The article (and others at e.g. the BBC) seem to say dogs "evolved" this capability in "a remarkably short time".<p>Is it not fairer to suggest that this is not evolution/natural selection at work here, but rather just selective breeding? I can't think of another species of animal that has been so widely twisted and manipulated in appearance by human's selective breeding than dogs.<p>Seems odd to suggest that <i>this</i> part of a dogs' body was due to evolution, but that rest of the crazy variety in dogs' body is not? A trait like this that humans like seems like is an obvious thing to get selected surely?<p>Or is there some strong evidence to suggest that this was really was nothing to do with selective breeding?
I wouldn't be surprised if humans haven't changed too since dogs befriended them. I imagine it's really a symbiotic relationship in the wild.<p>Both are social animals. Dogs have the speed and the teeth. Humans have the brain power, stone throwing and cooking. Dogs can mind the human young to a large extent and humans can feed the baby dogs cooked food. It's win win and a fearsome combination.
In my experience, the dogs ive been around dont generally look sad. The totality of their facial expressions show their emotion.<p>Ive a one year old pup, border collie/labrador mix. I can take a quick glance at his face and know exactly how he's feeling. Probably 80% of the time, its pure joy. Happy to run around, chew on toys, jump on the furniture and try and play (unrequitedly) with our cats. About another 10%, he's scared of other animals he can see out of the Windows of our townhouse and barks incessantly. The other 10%, I have no idea.<p>Eyes on a dog don't tell the whole story. Need to look at eyes, ears, back position, tail and legs to tell.<p>As I write this, my dog is laying against me, calm amd near sleep. Depending on perspective, I could see his face as seeming sad, but I know he's just sleepy. He's only awake because I am and I've not put him to bed yet. But his face says to me he's calm and content. His breathing is also slowing. His favorite chew toy is inches from his mouth and against my arm and he's content to let it stay there; that's how I know he's tired. If you were to just look at a photo of my dogs face right now, he might appear sad, but I know hes just calm and sleepy.
Dogs' eyes <i>don't</i> generally look sad, especially if they're quizzically raising <i>one</i> eyebrow. Why change the title from the much more interesting, and accurate original?<p>"Dogs’ Eyes Have Changed Since Humans Befriended Them"<p>I was actually expecting a dire clickbait sort of article, when it actually turns out to be substantive and interesting.
One of my favorite factoids is that the human-dog symbiosis evolved <i>twice</i>, in two unrelated corners of the world, at around the same time. It was meant to be.
They're talking a lot about the LAOM muscle which raises the eyebrow - I always thought it made dogs look more anxious than sad when they tense it - but they don't really talk about the RAOL muscle much.<p>> With dogs, Horowitz points out, we’re so driven to connect that we often search for “smiles” in the shapes of dogs’ mouths.<p>I think a lot of the "smile" facial expression you see on dogs is produced, not by the mouth, but by the RAOL muscle pulling the corners of the eyes out slightly to mimic the way humans' eyes squint slightly when we smile.<p>In any case, it'd be surprising if dogs <i>didn't</i> have some behavioural / communicative adaptations, given that their role in our lives has historically been a collaborative one. Look at all of the dramatic cosmetic changes we've made in selecting different breeds of dog. Surely selecting for increased utility as a hunting or farming animal would exert even more pressure?
As first reading the title I thought: “Really, that’s very interesting” Then I realized that almost everything about dogs have changed since humans befriended them. They literally went from wolves to pugs. Taking that into consideration it’s not at all surprising that the eyes changed too. Of cause it’s still interesting to dive in exactly how they’ve changed.
> By evolutionary standards, the time since this split [from wolves] has been remarkably short for two new facial muscles to have developed.<p>2 facial muscles? What about Chihuahuas to Great Danes, is that not a more impressive evolution than 2 facial muscles?
I always found dog eyes interesting. Some dogs have eyes that very animal like. I grew up around Miniature Schnauzers and their eyes are eerily human. The biggest difference is that the iris is a little too big. Were it not for that, I'd have a hard time distinguishing their eyes from ours.<p>I find that to be rather astounding actually. Given the wide variety of expressions Schnauzers at least are capable of emoting, it's pretty amazing how easy it is for two unrelated species to communicate on such a level. They speak a lot with their eyes. Look closely, you'll be amazed.
> It’s the first biological evidence scientists have found that domesticated dogs might have evolved a specialized ability used expressly to communicate better with humans.<p>It could be the other way around: when that kind of ability appeared humans have very selectively decided to prefer dogs that had that trait. Dogs are pretty much a human creation (through centuries of selective breeding) so it's not really evolution rather selection when it comes to this particular example.
I swear this article was timed perfectly with a top reddit /r/aww post earlier today. Being able to deduce intent and an expression from a dog's glance.<p><a href="https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_and_subtle_implication_that_he_is/" rel="nofollow">https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_a...</a><p><a href="https://gfycat.com/healthyfaintbilby" rel="nofollow">https://gfycat.com/healthyfaintbilby</a>
Direct link to the study referenced: <a href="https://www.pnas.org/content/early/2019/06/11/1820653116" rel="nofollow">https://www.pnas.org/content/early/2019/06/11/1820653116</a>
Isn't this better described as selective breeding, rather than evolution?<p>Maybe we haven't consciously bred the trait into dogs, but we might have selected such dogs for breeding, over litter mates that never made eye contact.