[extropy-chat] invariant be

[spike]

In Robin MacNeil's fascinating language program, a
recording made in the 1930s of African American speech
was played.  Curiously, the invariant "be" was completely
missing ("he be going" instead of "he is going).  

I had it in my mind that this signature ebonics 
usage was somehow adapted from Western African 
language groups, but now I am not at all
sure it isn't a fairly recent American invention,
perhaps in addition to the double negative often
heard in such speech.  

Has anyone ideas or speculations on where, when or
how the invariant be came to be?

spike