I'm a vegan, I don't think that it's justified to use, or deal with other animals without respect, or dignity. Emmanuel Kant said that you could judge someone's morality by how they treat animals. This plays well into observations of narcissists, and pyschopaths as well, whom don't treat people with decency or respect unless they think that they have to. Aristotle said that what he got from philosophy is that he followed the law because it was good, and not because it was the law.
There is no "natural order", or hierarchies in nature, of "more or less evolved", no ladders. To suggest a standard of treatment of others based merely on one's natural abilities, or capabilities (i.e. I can stomp on bugs, because I'm bigger, and capable of doing so, so this is justified and not wrong for this reason, etc) is counter-intuitive, clearly unrepresentative of moral sentiments. One uses one's powers where others lack them unselfishly, to promote equity, justice, and dignity where others cannot, and this is pro-social, and good. Because something is natural doesn't make it good, that's known as the naturalistic fallacy (informal fallacies may be questionable, but they're usually well recognized, and considered).
There's no such thing as "natural", or "the artifical" in the first place, they're just arbitrary categories, what we did a hundred thousand years ago was no more or less in harmony with nature than what we're doing now, the difference is in the power we possess to displace and affect the lives of other species, change the global climate, nuke the world, and such. Too much power, too much population, no viable realistic solutions that don't involve going until we destroy most of or all of the population by mistake, or willingly, and intently destroying most of the population, and dismantling dangerous powers willingly. Both are equally horrific, and without willing participants to stand in line for extinction, or returning to less industrial, smaller lives, the former ends up being the lesser of two evil, and the most likely outcome. I wouldn't think too hard about it, just live your life, be happy, trying to exercise more power than a small creature, concerned with its own life and circumstances needs is what got us into this mess to begin with, it won't get us out of it.
So... yeah... again' it.