nature of the new distinction

On page 60 Deleuze and Guattari say, “What some call the properties of human beings—technology and language, tool and symbol, free hand and supple larynx..are in fact properties of this new distribution [of content and expression.]." I’m interested in this reassessment of human evolution, in which the use of tools and the use of language are not determined as inherent aspects of humanity, but are rather, depicted as emergent processes of deterritorializations and reterritorializations. In this vein, once bodies could move upright, the hands were deterritorialized from their locomotive role, and reterritorialized as holding places for tools. The hand is, therefore, designated as the form of content, and the tools as the substance of this content—while the entire progression demonstrates the double articulation of form and substance. Similarly, the mouth is deterritorialized from its original form to be reterritorialized as a use for language. Language emerges, as the form of expression, while the “overall motricity of the face,” is the substance of this expression (61).   This co-emergence of hand-use and language-use seems to demonstrate the independent and parallel systems of content and expression.

I’ve been having trouble unpacking the nature of the indistinction between form and substance, and how it differs from the increasing autonomy of expression from content. Does the distinction between expression and content entail the ability for forms of expression to deterritorialize? I understand that at first, content and expression are depicted as inseparable and only distinguished by their molar vs. molecular properties. Then, in the organic stratum, “the nature of the distinction changes,” since both expression and content are determined as molecular and molar (58-59).  However, I don't understand the implications of this distinction, and have trouble following their description of the linguistic categories of content and expression in terms of concrete, physical concepts.  The over-arching "geology" concept I get, because of it's clear-cut departure from "genealogy," but the extended use of geological and biological references greatly complicates my understanding of the text.

I think that in further chapters, such as, "Postulates of Linguistics," the two heterogeneous "formalizations" of content and expression are more clearly defined.  "The independence of the form of expression and the form of content is not the basis for parallelism between them or a representation of one by the other, but on the contrary...a manner in which expressions are inserted into contents" (87).  The on-going slippage between one formalization and the other (the corporeal and incorporeal assemblages) is once again determined as alternating deterritorializations and reterritorializations.