Live data from Hacker News

Dogs’ Eyes Have Changed Since Humans Befriended Them

theatlantic.com

21–30 of 122 posts

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#21

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'…

Damn, I cannot wait to have a dog.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#22
> 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.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#23

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.

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.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#24
post #9

Earlier quoted context omitted.

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.

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 tha…

Did a cursory search and it seems to be common wisdom that all dog breeds have the same number of bones and muscles.

While there are many differences between breeds and individual dogs, there are also common factors that link them together. For example, all breeds have an excellent sense of smell and hearing and have the same number of bones which are tied together by the same number of muscles, tendons and ligaments.

https://breedingbetterdogs.com/article/structure-and-movemen...

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#26
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://www.dogwalkersmelbourne.com.au/articles-dog-walking-...

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#27

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.

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.)

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#28
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?

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#29
post #26

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.…

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.

Re: Dogs’ Eyes Have Changed Since Humans Befriended Them

#30
post #26

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.…

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.

Post reply on HN