LuisDantas, I often wonder whether I write in English or not. I cannot see how my comments are not understandable. I am not saying that you cannot understand plain English, rather it seems quite simple to me to read back what I have written. I get this quite a bit. Is it that there is little direct attention to detail or opinion, being that the opinion is subtle or is it that I am either opposing or agreeing with both arguements that I do not seem to express myself clearly.
Anyway, if you are saying human has been on the Earth for some 250,000 years, my point is that we have nothing to show it. Therefore I claim that human has been around a lot less time than that. By biological definition, especially of the brain, wouldn't you say that 243,000 years was spent doing SFA. Would you concur that, if evolution is the path we took, that humans as we are, are not of the time frame you have mentioned but something a little closer to say 7-10,000 years in existence. My guess it is less but I can settle with that.