The fact that not even just our senses, but our minds are so rooted in pursuit of pleasure and the avoidance of fear, and that we have lost any ability to be happy, might have evolved that way simply because we came from animals.
But although animals do operate by desire, they know who their master is, which is ecosystems. Ecosystems provide what animals need, and at times of plenty, they indulge the animals and the animals indulge themselves. At times of scarcity, they can not, but throughout all of that, animals always seem to have the ability to rest in a type of contentment nonetheless. Theirs is a faith that sooner or later qualia will lead them to what they need, if not necessarily what they desire. They are okay with that.
We are not.
What separates the humans from the animals is that an animal’s local consciousness is narrowly focused on their own landscape even though they may share a landscape or a niche with other organisms. Perhaps this is because, as has been observed in research, more choice does not lead to more happiness.
Human beings, on the other hand, have a much more expansive local conscious, and we do not share a niche with any creature (that we cannot enslave or annihilate). We have the ability uniquely to see ourselves in other landscapes, to see into other landscapes, not just other ecosystems, not just other landscapes of other animals and their individual perspectives perhaps, not just into other ecosystems and other niches, but also into other times and spaces. Our local consciousness has the potential to be universal.
I kind of have a mixed compassion for us having lost that ability to be content because of all that we can know and imagine.