Ecology and Exaptation All the Way in Language Evolution

I start with an explanation of what the “ecology of language”
means and how speakers and signers must be understood as the most direct
form of that ecology and as mediators and filters of the effects of
socioeconomic ecologies on language evolution. I then highlight various
insights that have been gained recently, from the past half-millennium
of the dispersal of Indo-European languages through colonization, about
the deterministic influence of the external ecology of a language (as
opposed to the internal ecology which lies within a language itself) on
its evolution. From this, I proceed to show why one must also factor in
the role of ecology, chiefly in the form of the scaffolding provided by
the anatomical and mental infrastructures, as well as by population
structure, to account for the protracted and incremental phylogenetic
evolution of language in the hominin species. To what extent does this
inclusive conception of “ecology” shed light on the successive
exaptations hominins made that have resulted in modern languages.
Finally, I show how this approach enables us to address the following
questions: How did typological linguistic diversity evolve? What kind of
role did contact (of populations and of languages) play in the
diversification of languages.