0005 What about Sinha’s EcoEvoDevoSocio framework?

0006 The outer terms, “eco” and “socio”, signify a broad arc of human evolution.

Adaptation by a line of apes starts with ecological adaptations.  For example, bipedalism is evolutionarily ancient.

However, the fact that bipedalism frees the hands for communicative gestures creates new opportunities.  A truly human niche appears.  One hominin can intentionally gesture to another.  The other hominin can interpret that gesture.

0007 The frontpiece of the title captures Sinha’s EcoSocio vision.  The praxis (or habits) of intentional manual-brachial gestures for communication proceeds from signaling to functional representation.

Functional representation metaphorically runs around the symbol, defined as a sign-relation whose sign-object depends on conventions, habits, laws and so forth.  The more that intentional manual-brachial gestures act as words, the more symbolic they become.

In this way, hominins become symbol-ready and capable of engaging in language.