bohm,
About the species thing. As i understand your position, you are saying that you believe it is plausible that wolf and dogs have the same common ancestor because they are quite 'similar', but eg. a human and a ape do not because they are to 'different' (correct me if i am wrong).
TD mentioned the example using wolves, dogs, foxes, etc. Wolves and dogs must have a common ancestor or else dogs came from wolves or wolves came from dogs because dogs and wolves can procreate and produce fertile offspring. For me "similar" doesn't mean anything. I think the test is the ability to produce fertile offspring. I don't think that humans and apes have a common ancestor for two reasons, humans are sentient (not exactly the right word, I will explain below) and apes are not and humans and apes cannot produce fertile offspring. I dont' think that humans and apes are similar at all, other than they both being bipedal. Being habitual bipeds puts them into a very select group of mammals and a select group of animals. There are very few habitual biped species.
Now, my point is that i have never seen anyone point out exactly what gap between man and apes evolution cannot pass - ie. what property(ies) that definately seperate an ape from a human. Is it that we walk upright? is it our brain capacity? etc.
This doesn't prove anything. You are assuming that apes are an ancestor of humans and then pose the question, "what properties separate them". I do not share that assumption. Humans are sentient, apes are not. I don't think that sentience can be the result of evolution. (I know sentience is not exactly the right word).
Sentience. Okay, I used the word sentience but that is not actually the correct word. I'm not sure what the right word is, and I know that the philosphy types, the "I am therefore I do not exist because the tree fell and a woman was not there to complain about it" types can object to whatever word I use.
Humans have a capability to think in a way that animals do not have and will never have. I know, the animal rights nut jobs will go ballistic at that statement, I'm cool with that. I do not believe that this ability could be a product of evolution. And, yes, I am having troube being very specific as to just what this capability is/entails. As,I go through the list of things that humans do that animals don't do I can find examples of different animals doing specific items in the list to a more or lesser degree. For example, I have lots of trees and I watch squirrels out my window while working. They can learn, plan ahead, cooperate, play pranks on other animals (they love to torment cats), they have a sense of humor, they like to play, they will hoard food when it is in abundance, they set up sentries to watch for danger when gathering food, well the list is pretty long. But, a squirrel will always be a squirrel, a squirrel will never become an architect or a deep sea diver or a down hill skier or a mathematician. Squirrels do not wonder why they were put on this earth or what happens to them after they die. They don't have five year plans. They don't know what happened one hundred years ago and they don't care. I'm sorry but I can't put those qualities into words. But I think you can figure out what I am talking about.