Paleontologists argue endlessly over whether a particular fossil belongs in Homo or Australopithecus. Amusingly if you give the same fossil sequence to a bunch of creationists they can't agree which is ape and which is human. All distinctions are arbitrary
So you don't believe that we are different. I see. The facts don't support your conclusion. You are not holding yourself up to your own scientific standards.
Lets go back to the animals, not because I want to drag that out again, but I guess I do.
Your type (sorry to sterotype, but I see patterns) seems to find it perfectly stomachable to speak for the animals and judge whether or not they "suffer." To make a point of course. It's not only you it's a lot of other people too (including me). We want to "save the animals" we wan't to help them escape extinction. It's noble and admirable from a certain moral perspective.
Even the Bible says the "animals are in subject to the man." We named them! There ya go, we're arrogent. Maybe that's what separates us from the animals. We think we have a say in things.
And here come the the scientists again. Cataloging everything and developing/uncovering law. The true pursuit of truth! Another noble choice from a certain moral perspective.
When science speaks of the "old humans" like neaderthals and the like I feel as if I am talking to a fortune teller trying to commune with my ancestors. You don't know them, I don't know them. We have the things they left behind that random time and erosion has preserved for us. The whole picture is actually just a book of fantasy that will never be truly exposed in our lifetimes (I don't think). We still use brushes to uncover our past!
We are different and the observations to support that conclusion are yours for the taking. Why do we feel the need to use our "brushes" to meticulously dig up our past and explain it? Why do some use it for Good and some use it to distort truth to further an agenda? Why do we have passion? We are different, man, and no bones in the ground, no matter how they are presented, are going to change that.
-Sab