That answer has been provided several times in this thread already. You choose to ignore it because you refuse to acknowledge the superiority of the scientific methodology.
It has...but it is not that explicit enough though...mainly because there is like what? Half a dozen answers? Sure they are interlinked in some way, I was hoping for a more...general answer? While on the other hand, I'm not sure if I was looking for a specific answer...
Master fire? Several species of Homids has done that.
Make use of tools? Several apes has done that as well.
Other than DNA wise...and focusing on physical acts wise...I'm not sure are we able to even put it under similar acts or different.
Maybe we can use a mixed classification to label the sentience or sapience level of a species. On the other hand, this is going to get even more confusing. Which means it will be more confusing if we decided to rely on physical acts of a species to define it.
Ray's problem is that he's looking for some kind of black/white distinction, instead of something where we just have barely enough of a certain natural trait (such as intelligence) to have painstakingly built up an infrastructure over thousands of years which can achieve novel things.
Personally, I think is because I have no clear idea what am I really looking for. Gray? Black and white answer?
I hate this kind of question...and asking me to write an essay on it is going to make your mind...insane? Hell, I'm surprised I'm not in a mental hospitial by now...