10 ms·

Dogs’ Eyes Have Changed Since Humans Befriended Them

251 points by gilad 7y ago

NeedMoreTea 7y ago
Dogs' eyes don't generally look sad, especially if they're quizzically raising one eyebrow. Why change the title from the much more interesting, and accurate original? "Dogs’ Eyes Have Changed Since Humans Befriended Them" I was actually expecting a dire clickbait sort of article, when it actually turns out to be substantive and interesting.
- tlb 7y ago
  Title changed from "Why do dogs look sad", thanks.
  - notatoad 7y ago
    thanks for leaving a comment that includes the old title. it's always confusing when the title gets silently changed, and then there's comments complaining about a title that's no longer the title.
    - gilad 7y ago
      agreed, see my comment above to the initial and justified complaint.
- gilad 7y ago
  [poster here]: Interesting find - my phone showed the title as 'Why Do Dogs Look So Sad?', where the actual article's title is different. Looking at the page's source code under the <title> tag shows these are different. I chose the shorter version (nevermind dropping the 'so' in 'so sad' cause that's really click-bait-y). My assumption was that readers would know that the source (the Atlantic) is a reputable publication and assume the article is of substance. It's interesting that even the Atlantic needs to resort to changing the title to get those coveted clicks. In the future, i'll strictly post the _actual title_ over to HN submission.
  - NeedMoreTea 7y ago
    Hm, never knew Atlantic played that game too. I know Ars A/B tests titles, and that a few of the buzzfeed type publications put a social title (ie clickbait fest) for the first day or two while a piece does the rounds of Facebook and Twitter, and replace with a sane "forever" search engine title later. At the other extreme there's the odd dry-as-dust titled technical article that really needs some editorialising or at least posting on sub-head to have any chance of interest.
- ken 7y ago
  The "Sad" version is in the <title>. That usually means that is the original, and they changed the <h1>.
taneq 7y ago
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. > With dogs, Horowitz points out, we’re so driven to connect that we often search for “smiles” in the shapes of dogs’ mouths. 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. In any case, it'd be surprising if dogs didn't 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?
ralusek 7y ago
> By evolutionary standards, the time since this split [from wolves] has been remarkably short for two new facial muscles to have developed. 2 facial muscles? What about Chihuahuas to Great Danes, is that not a more impressive evolution than 2 facial muscles?
- Raticide 7y ago
  I think it's because chihuahuas and great danes have all the same bits, just with different scales/shapes. Where as entirely new muscles take a lot more work to evolve.
  - philwelch 7y ago
    And bone structure, just forget it. Mammals have mostly the same sets of bones attached the same way--a bat's wings are just gigantic hands with webbed fingers in skeletal terms.
    - grawprog 7y ago
      The order all bats are part of, Chiroptera, translates to hand-wing because of this webbed hand wing structure.
  - barry-cotter 7y ago
    I'd be very surprised if Chihuahuas and Great Danes literally have all the same bits. Canines are the most morphologically diverse animal, surpassing even humans. If there aren’t dog breeds that all have or lack a particular muscle, type of hair or bone I’ll be very surprised. Poodles have webbed feet for one, or just consider how some breeds have floppy and others pointed ears. It’s reasonably likely the muscles that are universal among dogs existed among wolves at very low frequency and just exploded in frequency once they started hanging around humans. These kinds of hard sweeps happen when there’s either a very useful de novo mutation or a new environment makes a previously irrelevant or disadvantageous allele or trait beneficial. In humans think lactase persistence which was pretty much nonexistent 5,000 years ago or the Tibetan altitude adaptations which derive from the Denisovans who were living on the Tibetan plateau over a million years ago.
hermitdev 7y ago
In my experience, the dogs ive been around dont generally look sad. The totality of their facial expressions show their emotion. 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. Eyes on a dog don't tell the whole story. Need to look at eyes, ears, back position, tail and legs to tell. 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.
- NetOpWibby 7y ago
  Damn, I cannot wait to have a dog.
  - jyriand 7y ago
    Getting a dog should not be an emotional decision. I have a dog and sometimes it's a lot of work. Feeding, pooping, pissing, neverending fur in the house and on my clothes, vet, constant attention seeking etc. Just to mention a few things. And if you need to travel you need a babysitter for your dog. It's easier if you have a backyard where the dog can chill.
    - maccard 7y ago
      Can confirm. I am sitting here with a 9 week old puppy that I've had since Friday. It's relentless at first.
      - 7y ago
skunkworker 7y ago
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. https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_and_subtle_implication_that_he_is/ https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_a... https://gfycat.com/healthyfaintbilby https://gfycat.com/healthyfaintbilby
- deleted 7y ago
  [deleted]
deleted 7y ago
[deleted]
_bxg1 7y ago
One of my favorite factoids is that the human-dog symbiosis evolved twice, in two unrelated corners of the world, at around the same time. It was meant to be.
- henryackerman 7y ago
  Got a source on that? Seems like an interesting read.
  - _bxg1 7y ago
    https://science.sciencemag.org/content/352/6290/1228 https://science.sciencemag.org/content/352/6290/1228
sunstone 7y ago
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. 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.
- onemoresoop 7y ago
  I’ve had the exact thoughts. And in fact all domesticated animals change and we change with them as well. Im not only thinking about pets but the all animals that live in (an unfair) symbiosis with humans.
  - GorgeRonde 7y ago
    I watched a documentary about domestication a while back. Turns out there are many "corollary features" to being domesticated: for instance, ears falling down are also to be found in domesticated fox. One of the most common feature across domesticated species was tighter jaws. Source: https://www.youtube.com/watch?v=_6Zep-GhQYU https://www.youtube.com/watch?v=_6Zep-GhQYU
- Causality1 7y ago
  It would be interesting to look for genetic differences between human populations with a history of intensive domestication like the Maasai and populations that have no or only recent domestication like aboriginal Australians.
  - rags2riches 7y ago
    Adults that can digest lactose is one trait obviously related to animal husbandry.
olalonde 7y ago
> objectively cuter For sure.
ekianjo 7y ago
> 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. 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.
MarcScott 7y ago
Isn't this better described as selective breeding, rather than evolution? 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.
- arnarbi 7y ago
  For the dog, it's just evolution under some environmental factors. One of the factors just happens to be human behavior. (But it's typical and common human hubris to not call nature nature when it includes us.)
- Retra 7y ago
  Selective breeding is still evolution.
Joakal 7y ago
This is a good opportunity to educate the general [HN] community about dogs: 1. They can only see blue/yellow. Not like humans' RGB. 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. 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. More: https://dog-vision.com/ https://dog-vision.com/ https://www.dogwalkersmelbourne.com.au/articles-dog-walking-pet-sitting/66-dog-canine-vision-seeing-compare-human.html https://www.dogwalkersmelbourne.com.au/articles-dog-walking-...
- sl1ck731 7y ago
  The flickering thing has always made me feel bad for my dog and dogs in general. My entire office room is monitors/TVs and I can only imagine what she sees, like a rave 24/7. But she will still sleep in here when she can go anywhere else in the house.
- interfixus 7y ago
  My 12 year old labrador is in excellent shape, but his hearing is no longer quite up to scratch, and to avoid embarrassing levels of shouting when we are out and about, I increasingly use pointing and other signs at my end of our communication. Also, his left eye has been problematic for many years, and apparently only registers the haziest of outlines these days. And yet, he contantly amazes me by the range and precision of his vision. Downwards pointing with my left arm means come here at once, which he will reliably register at a distance more than a hundred meters. Other dogs he will recognize at distances further than that, and he will unerringly home in on thrown stick bobbing on the water, as long as it's on the right, where his good eye can see. Clearly, there's more to it than just they are short sighted.
  - dunstad 7y ago
    As a nearsighted human who didn't get glasses as early as he should have, I used to use people's gait or clothing to recognize them at long distances. You know your dog best, just saying there can be ways to compensate.
mattlondon 7y ago
The article (and others at e.g. the BBC) seem to say dogs "evolved" this capability in "a remarkably short time". 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. Seems odd to suggest that this 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? Or is there some strong evidence to suggest that this was really was nothing to do with selective breeding?
- hoseja 7y ago
  What else is selective breeding than evolution where fitness is strongly influenced by a hairless ape?
  - viscanti 7y ago
    The article mentions that the trait is observable at only 4 weeks old. It might not be crazy to think that Humans are more likely to select the puppies that demonstrate the trait. It might not be "natural" selection, but if Humans are making a substantial amount of the breeding decisions for dogs then it could still be a form of evolution.
    - quietbritishjim 7y ago
      Indeed, selective breeding is sometimes called "artificial selection" as a mirror to the term "natural selection". Both are types of evolution.
- NeedMoreTea 7y ago
  I'm mostly comfortable with thinking it's evolution as crazy variety and selective breeding came very late to the party. Most in the last few hundred years - lots of the breeds we know are from the 17th, 18th and 19th centuries. I would guess that for most of our co-existence breeding was up to the dog to figure out, which might explain the oldest breeds being of a particular region. Task breeds came very much later. Edit: Also, how do you selectively breed for muscles that didn't previously exist?
brazzy 7y ago
https://www.smbc-comics.com/comic/wolves https://www.smbc-comics.com/comic/wolves
hjk05 7y ago
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.
jumpinalake 7y ago
I wish this article included photos comparing the look of a dog face when using vs not using the cited muscles.
thebeefytaco 7y ago
Direct link to the study referenced: https://www.pnas.org/content/early/2019/06/11/1820653116 https://www.pnas.org/content/early/2019/06/11/1820653116
bmurphy1976 7y ago
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. 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.

251 points by gilad 7y ago

Dogs' eyes don't generally look sad, especially if they're quizzically raising one eyebrow. Why change the title from the much more interesting, and accurate original? "Dogs’ Eyes Have Changed Since Humans Befriended Them" I was actually expecting a dire clickbait sort of article, when it actually turns out to be substantive and interesting.

tlb 7y ago
Title changed from "Why do dogs look sad", thanks.
- notatoad 7y ago
  thanks for leaving a comment that includes the old title. it's always confusing when the title gets silently changed, and then there's comments complaining about a title that's no longer the title.
  - gilad 7y ago
    agreed, see my comment above to the initial and justified complaint.
gilad 7y ago
[poster here]: Interesting find - my phone showed the title as 'Why Do Dogs Look So Sad?', where the actual article's title is different. Looking at the page's source code under the <title> tag shows these are different. I chose the shorter version (nevermind dropping the 'so' in 'so sad' cause that's really click-bait-y). My assumption was that readers would know that the source (the Atlantic) is a reputable publication and assume the article is of substance. It's interesting that even the Atlantic needs to resort to changing the title to get those coveted clicks. In the future, i'll strictly post the _actual title_ over to HN submission.
- NeedMoreTea 7y ago
  Hm, never knew Atlantic played that game too. I know Ars A/B tests titles, and that a few of the buzzfeed type publications put a social title (ie clickbait fest) for the first day or two while a piece does the rounds of Facebook and Twitter, and replace with a sane "forever" search engine title later. At the other extreme there's the odd dry-as-dust titled technical article that really needs some editorialising or at least posting on sub-head to have any chance of interest.
ken 7y ago
The "Sad" version is in the <title>. That usually means that is the original, and they changed the <h1>.

taneq 7y ago

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. > With dogs, Horowitz points out, we’re so driven to connect that we often search for “smiles” in the shapes of dogs’ mouths. 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. In any case, it'd be surprising if dogs didn't 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?

ralusek 7y ago

> By evolutionary standards, the time since this split [from wolves] has been remarkably short for two new facial muscles to have developed. 2 facial muscles? What about Chihuahuas to Great Danes, is that not a more impressive evolution than 2 facial muscles?

Raticide 7y ago
I think it's because chihuahuas and great danes have all the same bits, just with different scales/shapes. Where as entirely new muscles take a lot more work to evolve.
- philwelch 7y ago
  And bone structure, just forget it. Mammals have mostly the same sets of bones attached the same way--a bat's wings are just gigantic hands with webbed fingers in skeletal terms.
  - grawprog 7y ago
    The order all bats are part of, Chiroptera, translates to hand-wing because of this webbed hand wing structure.
- barry-cotter 7y ago
  I'd be very surprised if Chihuahuas and Great Danes literally have all the same bits. Canines are the most morphologically diverse animal, surpassing even humans. If there aren’t dog breeds that all have or lack a particular muscle, type of hair or bone I’ll be very surprised. Poodles have webbed feet for one, or just consider how some breeds have floppy and others pointed ears. It’s reasonably likely the muscles that are universal among dogs existed among wolves at very low frequency and just exploded in frequency once they started hanging around humans. These kinds of hard sweeps happen when there’s either a very useful de novo mutation or a new environment makes a previously irrelevant or disadvantageous allele or trait beneficial. In humans think lactase persistence which was pretty much nonexistent 5,000 years ago or the Tibetan altitude adaptations which derive from the Denisovans who were living on the Tibetan plateau over a million years ago.

hermitdev 7y ago

In my experience, the dogs ive been around dont generally look sad. The totality of their facial expressions show their emotion. 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. Eyes on a dog don't tell the whole story. Need to look at eyes, ears, back position, tail and legs to tell. 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.

NetOpWibby 7y ago
Damn, I cannot wait to have a dog.
- jyriand 7y ago
  Getting a dog should not be an emotional decision. I have a dog and sometimes it's a lot of work. Feeding, pooping, pissing, neverending fur in the house and on my clothes, vet, constant attention seeking etc. Just to mention a few things. And if you need to travel you need a babysitter for your dog. It's easier if you have a backyard where the dog can chill.
  - maccard 7y ago
    Can confirm. I am sitting here with a 9 week old puppy that I've had since Friday. It's relentless at first.
    - 7y ago

skunkworker 7y ago

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. https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_and_subtle_implication_that_he_is/ https://www.reddit.com/r/aww/comments/c1qt1x/doggos_polite_a... https://gfycat.com/healthyfaintbilby https://gfycat.com/healthyfaintbilby

deleted 7y ago
[deleted]

deleted 7y ago

[deleted]

_bxg1 7y ago

One of my favorite factoids is that the human-dog symbiosis evolved twice, in two unrelated corners of the world, at around the same time. It was meant to be.

henryackerman 7y ago
Got a source on that? Seems like an interesting read.
- _bxg1 7y ago
  https://science.sciencemag.org/content/352/6290/1228 https://science.sciencemag.org/content/352/6290/1228

sunstone 7y ago

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. 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.

onemoresoop 7y ago
I’ve had the exact thoughts. And in fact all domesticated animals change and we change with them as well. Im not only thinking about pets but the all animals that live in (an unfair) symbiosis with humans.
- GorgeRonde 7y ago
  I watched a documentary about domestication a while back. Turns out there are many "corollary features" to being domesticated: for instance, ears falling down are also to be found in domesticated fox. One of the most common feature across domesticated species was tighter jaws. Source: https://www.youtube.com/watch?v=_6Zep-GhQYU https://www.youtube.com/watch?v=_6Zep-GhQYU
Causality1 7y ago
It would be interesting to look for genetic differences between human populations with a history of intensive domestication like the Maasai and populations that have no or only recent domestication like aboriginal Australians.
- rags2riches 7y ago
  Adults that can digest lactose is one trait obviously related to animal husbandry.

olalonde 7y ago

> objectively cuter For sure.

ekianjo 7y ago

> 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. 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.

MarcScott 7y ago

Isn't this better described as selective breeding, rather than evolution? 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.

arnarbi 7y ago
For the dog, it's just evolution under some environmental factors. One of the factors just happens to be human behavior. (But it's typical and common human hubris to not call nature nature when it includes us.)
Retra 7y ago
Selective breeding is still evolution.

Joakal 7y ago

This is a good opportunity to educate the general [HN] community about dogs: 1. They can only see blue/yellow. Not like humans' RGB. 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. 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. More: https://dog-vision.com/ https://dog-vision.com/ https://www.dogwalkersmelbourne.com.au/articles-dog-walking-pet-sitting/66-dog-canine-vision-seeing-compare-human.html https://www.dogwalkersmelbourne.com.au/articles-dog-walking-...

sl1ck731 7y ago
The flickering thing has always made me feel bad for my dog and dogs in general. My entire office room is monitors/TVs and I can only imagine what she sees, like a rave 24/7. But she will still sleep in here when she can go anywhere else in the house.
interfixus 7y ago
My 12 year old labrador is in excellent shape, but his hearing is no longer quite up to scratch, and to avoid embarrassing levels of shouting when we are out and about, I increasingly use pointing and other signs at my end of our communication. Also, his left eye has been problematic for many years, and apparently only registers the haziest of outlines these days. And yet, he contantly amazes me by the range and precision of his vision. Downwards pointing with my left arm means come here at once, which he will reliably register at a distance more than a hundred meters. Other dogs he will recognize at distances further than that, and he will unerringly home in on thrown stick bobbing on the water, as long as it's on the right, where his good eye can see. Clearly, there's more to it than just they are short sighted.
- dunstad 7y ago
  As a nearsighted human who didn't get glasses as early as he should have, I used to use people's gait or clothing to recognize them at long distances. You know your dog best, just saying there can be ways to compensate.

mattlondon 7y ago

The article (and others at e.g. the BBC) seem to say dogs "evolved" this capability in "a remarkably short time". 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. Seems odd to suggest that this 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? Or is there some strong evidence to suggest that this was really was nothing to do with selective breeding?

hoseja 7y ago
What else is selective breeding than evolution where fitness is strongly influenced by a hairless ape?
- viscanti 7y ago
  The article mentions that the trait is observable at only 4 weeks old. It might not be crazy to think that Humans are more likely to select the puppies that demonstrate the trait. It might not be "natural" selection, but if Humans are making a substantial amount of the breeding decisions for dogs then it could still be a form of evolution.
  - quietbritishjim 7y ago
    Indeed, selective breeding is sometimes called "artificial selection" as a mirror to the term "natural selection". Both are types of evolution.
NeedMoreTea 7y ago
I'm mostly comfortable with thinking it's evolution as crazy variety and selective breeding came very late to the party. Most in the last few hundred years - lots of the breeds we know are from the 17th, 18th and 19th centuries. I would guess that for most of our co-existence breeding was up to the dog to figure out, which might explain the oldest breeds being of a particular region. Task breeds came very much later. Edit: Also, how do you selectively breed for muscles that didn't previously exist?

brazzy 7y ago

https://www.smbc-comics.com/comic/wolves https://www.smbc-comics.com/comic/wolves

hjk05 7y ago

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.

jumpinalake 7y ago

I wish this article included photos comparing the look of a dog face when using vs not using the cited muscles.

thebeefytaco 7y ago

Direct link to the study referenced: https://www.pnas.org/content/early/2019/06/11/1820653116 https://www.pnas.org/content/early/2019/06/11/1820653116

bmurphy1976 7y ago

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. 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.