'The Ecology of Written Language'

So, just how far will Barton extend the metaphor of ecology? As I'm reading (and construct my own understanding of the metaphor), I'm beginning to understand the usefulness of ecology as a description of what is really happening when we use the terms literacy, literate, illiteracy, and illiterate. Interestingly, I was surprised to learn that the terms, in their current usage, are relatively new and continually evolving. I think I may have been under the impression that 'literacy' has been in similar pedagogical use since my grandparents' school days (which was in the early part of last century).

I'm recognizing that literacy is a concept that can't be described as a skill set or a portion of a larger system, rather it is connected to elements throughout the system. I particularly like Barton's description on page 31, "...the structure and patterns in a community are a product of processes at the level of the individual."

So, what does the 'ecosystem' of literacy look like? This is the understanding that I'm constructing.

Finally, a favorite line from this text so far:
"[Metaphors] are like the tips of icebergs..." (p. 17)