Yes, we are animals, but unlike all of the other animals on the planet, our species serves no purpose in any ecosystem. Humans are a blight on this planet, even worse than feral animals, we are an overpopulated scourge, which pillages the planet for it's natural resources.
That doesn't make us better than any other animal. Quite the contrary, if we were gone, this planet would thrive without us.
The words human, humane and humanity are kind of a joke. We are capable of "humanity", but our humane practices are infinitesimal compared to our destruction.
And yes - we EVOLVED, over millions of years, just like the majority of species on this planet. We were not suddenly dumped here by some diety. We simply evolved faster. But we haven't evolved entirely - we are still animals, capable of murder, cruelty and ruthlessness. The only difference between us and other animals is that we actually realize our wrongs, even if we appear to be helpless to prevent them.
And therein lies the truth, and our biggest problem as a species. Some of us realize that we need to be a part of the ecosystems that we inhabit, and the rest don't care. Those people live more like animals than they are willing to admit. They take what they need or want from the earth, without regard for the impact to our planet or the future of mankind.
As for the animals, they are treated as resources and commodities. And as such, it's acceptable for some to treat animals like objects, without feelings. Especially animals who are bred and raised for consumption. And you're right about pigs. They are smart. If pigs were pets and not food, we would treat them better.
Our pets are slightly elevated. Although they are given little protection from our cruelties, it is generally unacceptable to harm them, because they are companions - not a food source.
The reason why it's more of a crime to harm a human is because the line had to be drawn somewhere. The minute that it becomes a severe crime to harm any animal, we must consider that all animals being raised for consumption are going to be "murdered", not butchered. And as a species that consumes vast amounts of meat and other animal based products, that wont happen any time soon.
As long as we humans, being part of humanity, and being all "humane", continue to kill each other, there is little hope for the other animals who must share this planet with us.