I don't think anyone has yet brought up the point that we are entirely dependent upon the earth. One small shift in axis or gravitational pull and we are all ash or icicles.
Not to mention, the gaseous layers over our heads that keeps deadly radiation out, the same layers we keep on Lysoling away. As bent and obsessed with self-destruction, I choke on a description of humanity as intelligent: We know a great deal, we have the capacity to live good lives based upon our knowledge, but we choose not to.
As vicious as it may be, the animal kingdom is also self-sufficient; Animals know their needs and they consume, contribute, and reproduce as fast as they can, filling the earth with ever more species and variety. Humanity has had its tendency to kill the animal kingdom, mutilate plants, and leave behind enormous concrete tombstones of cities over once beautiful lands. And then to trumpet their superiority, they go about killing each other. There are hundreds of wars raging this very minute, not to mention our enormous human potential for the future in the form of nuclear warheads aimed at every major city.