The only thing I would point out to Isaac is that the human brain is NOT "more evolved" than any other brain functioning today. We aren't the apex of anything. That is a basic misunderstanding of evolution.
There is no apex.
(There is no spoon...)
A bloodworm is just as exquisitely evolved for its niche as humans are. You can't even claim that humans are more complex than other animals- because we aren't. We're just specialized in different ways. A crayfish has more chromosomes than we do, for example. As do many plants- though that's a technicality, because they tend to be polyploid.
That said, I do, personally, place a bit of cache upon sentience. I think it imposes upon us a higher standard of behavior, as Craig alluded to. Just because we can do something doesn't mean that we should. Because we CAN do some pretty dramatically horrible stuff. Oppenheimer, anyone? Ergo morality, et al.
I guess I agree- Timothy Treadwell was "harmless enough." Well, unless you count that friend whom he convinced it was safe to frolick with feeding brown bears like they were in some sort of reality Disney movie...
Wow. That's an image that will haunt me for the rest of my life. Especially if you look at all like your avatar. Puppy self-abuse is never pretty.