Progressive aspect as an innovation in Central Zapotec

An updated version of my paper about the evolution of progressive aspect in Central Zapotec languages has just been posted on my page at Academic.edu.

My essential argument is that progressive aspect marking with ca- is innovation in Central Zapotec, and you can still see the early stages of this in Colonial Valley Zapotec.  In the 16th century texts, ca- isn't yet an obligatory marker of progressive (as it is in modern languages in this group).

The Central Zapotec languages include the ones shown in this tree (some branches omitted for visibility), using the classification of Thom Smith Stark (2007):

Central Zapotec languages

The tree below is the current version of something that I am working on.  It's intended to show major branches of Central Zapotec (according to the classification of Smith Stark 2007), and it also shows (in brackets and italics) where we currently have Colonial Valley Zapotec documents in our FLEx corpus.

I know that there are many other Colonial Valley Zapotec documents out there, so the tree will get 'bushier' over time, but I found this a useful graphic view of where the documents come from in terms of distribution.