Writing and Evolution

According to the best evidence, Writing is only a relatively recent development in Human history.  Still, that Writing seems to be a mode of communication that is unique to the species, and that it has been essential to the arc from first appearance in the terrestrial habitat, to departure from that habitat, indicates its Evolutionary significance.  Now, the immediate value of Writing is that its product transcends the moment of its production, thereby becoming indefinitely available to others, at other times, in other places.  Thus, if Derrida is correct to subvert the traditional Thought-Speech-Writing hierarchy, then, intellectual tools like Concepts and Definitions, and Philosophical staples such as Universality and Eternity, are byproducts of the Evolution of the Human species, rooted in the emergence of the thumb that makes Writing possible.