LOL! How convenient. Just shrug off human progress because it goes against your argument.

I admit there were very negative side effects of each of those points I made. In crossing this country the "civilized" races destroyed a series of complex and highly developed cultures that got in their way. The same type of argument dribbles down through your entire post.

But the point is... we don't KNOW what we can do until we try. You apparently don't even want to do that. I detect the heavy sigh of regret in your post. I seem to hear the tapping of hammers as you start to construct your tomb. But is that what we really want to do, give up and roll into our graves? A few million years ago our ancestors had the choice of leaving the trees for the far more dangerous ground. Where would we be if they all said, "It's no use. We might as well stay here."?