Actually given that dogs score better than chimps, wolves and human infants in tests of social cognition would lend credence to the fact that humans are actually inadvertently creating sentience. Similarly dogs are the only non-primate species to look at the right side of a persons face to gauge their emotion and state, but unlike primates and humans, they don't do this with other species or dogs.
Evidence points to dogs having a limited theory of mind, in that they can actively be deceitful, meaning they can understand the perceptions of other animals.
Not to mention, dogs are already known to have the ability to rationalise, empathise and have abstract learning abilities. They're capable of the whole range of human emotions, including clinical depression, melancholy, anger, rage, etc. Beyond that, they're capable of empathetic sadness and anger. They also display the same ability as many of the great apes to mourn their dead, but notably dead humans.
Orangutans are largely being made extinct for the same reason that humans have made wolves and tried to make numerous other species such as foxes, rabbits, etc. extinct. In that they're pose a risk to our economic livelihoods. Orangutans are dying because of deforestation and poaching.
Wolves evolved into a evolutionary niche as dogs, and as dogs have become as wide spread a species as humans and have evolved far beyond their ancestors. To the point that they actually rank above primates in certain tests of cognition and social behaviour - notably the two behaviours that are attributed as key elements of human evolution to sentience.
Having lived with the "best friends" of humans (cats and dogs) for many years, I am no longer sure what "sentience" is because I find the difference between us and them in everything to be a matter of degree.
We're _better_ at being 'sentient' than they are, but I can't find anything that we do that they don't. I'm serious here. You totally hit the nail on the head when you talk about anger and empathy.
They can learn, they can feel, they can teach their offspring, they can empathize, they can demonstrate their emotional and physical needs, and they can communicate both with us and amongst themselves. They know right from wrong (keeping in mind that in reality there are no moral absolutes and right and wrong very much relative concepts even to humans, and even on what we consider to be an axiomatic basis).
Just be careful not to project your own humanity onto your pets, if you want to see them more objectively. Radiolab had a great episode on "animal minds" that went into some of the biases dog owners have about their pets. In a sense, we're actually disrespecting other animals by judging them on a scale of "how humanlike is their behavior" and too easily discounting the things that make them unique and unlike us.
I have two dogs, both from the local SPCA. My first was a stray and came to us with full blown anxiety. She used to have separation anxiety from people she'd just met (literally a friend dropped in for 5 minutes just to see her and she spent 20 minutes panicked and crying when he left). However, she's the happiest dog anyone (and I'm really not exaggerating that) has ever seen.
My second dog was abandoned by his owner, completely neglected (skinny, no muscle mass whatsoever, he literally struggled jumping onto a couch, and the SPCA had to shave him almost bald to get rid of the mattes) but that has no effect on the fact that he was depressed and angry over it. When we started training him he became pissy, jumped up on our bed and took a giant shit on it and that's from a 4 year old dog that's never had an accident in our house.
However, the second dog has recently become the bodyguard for the first. We've only had him 3 months, but around other dogs that are overly aggressive in how they tell off another dog (she's barely 2 years old, so a lot of older dogs are very assertive in how they correct her) he has taken to blocking them. He doesn't become aggressive, but when she is nervous or panicked he seems to step in and block, and it's funny because you'll see him for 5 minutes just blocking a dog from getting to her. Even when he gets snarled or snapped at he carries on until the other dog backs off. It's when she submits (rolls on her back, occasionally pees) to other dogs that you see him become angry as he (normally a silent dog) will bark and growl at the other dog and guard her. This happens all the time with our trainers boarder collie (they don't like excitement and our first dog is a jack russell mix, so is basically excitement personified) and there'll be 5 minutes of them squaring off barking at each other and him keeping the trainers dog from our first.
Our first dog knows right from wrong and when she's done wrong. If she knows I've noticed something she's done wrong (like torn up a burger wrapper) she goes into full blown submission and often pees on herself (it's a girl dog way of stopping another dog from attacking her). Our second however either doesn't know or doesn't give a shit about right from wrong.
my greatest personal epiphany was when i saw that while we're longing for other intelligence and looking for it out there, there is an other intelligence right near with us.
Interestingly enough birds are the one group that systemically destroys the sentience tests.
One test, the Mirror Self Recognition test was thought to only be accomplished by humans and the great apes, even monkeys aren't capable (in the traditional sense). However the humble pigeon passes, and not an occasional get lucky pass, but pigeons just nail the test.
Tool use was one of the very classical 'gateways' to sentience argued for humans. Except there appear to be far more bird species than mammal species that regularly use tools. Further than this, Herring Gulls are noted for tool-use hunting by using pieces of bread to hunt goldfish - which essentially one-ups all other known tool users.
Ravens are one of the few species who actually make the toys they play with. IE they don't find a stick and play, but will break twigs off of trees and brushes with the intent of using it to play with others.
Evidence points to dogs having a limited theory of mind, in that they can actively be deceitful, meaning they can understand the perceptions of other animals.
Not to mention, dogs are already known to have the ability to rationalise, empathise and have abstract learning abilities. They're capable of the whole range of human emotions, including clinical depression, melancholy, anger, rage, etc. Beyond that, they're capable of empathetic sadness and anger. They also display the same ability as many of the great apes to mourn their dead, but notably dead humans.
Orangutans are largely being made extinct for the same reason that humans have made wolves and tried to make numerous other species such as foxes, rabbits, etc. extinct. In that they're pose a risk to our economic livelihoods. Orangutans are dying because of deforestation and poaching.
Wolves evolved into a evolutionary niche as dogs, and as dogs have become as wide spread a species as humans and have evolved far beyond their ancestors. To the point that they actually rank above primates in certain tests of cognition and social behaviour - notably the two behaviours that are attributed as key elements of human evolution to sentience.