I think you're missing the implications of what you're saying. The original question from the opening post was this:
How long has modern man been on this earth?
This context of the question is the biological evolution of man, as Shekinah made clear when he touched on the topics of evolution and how it relates to the origin of life in his Message 10. Shekinah was asking how long ago Homo sapiens sapiens evolved into their present form.
But instead of defining modern man in biological terms, you're defining him in intellectual terms as "humans with the abilty to write." That's an interesting reinterpretation of the question, but it isn't the topic of this thread, unless you're contending that the ability to write was a 5000 year-old evolutionary event.