Re: IE, AA, Nostratic etc.

The word that I'm not seeing in this discussion is "cladistics".
This is a study developed mostly by the biologists in formalizing
the taxonomy of life. They've accomplished a great deal here; I
wonder if linguistics could profit by snatching some of its ideas.
The main obstacle would be linguistic crossover (you have a term
for it) -- words from one language being adopted in a completely
unrelated language. This would be analogous to a horse mating with
plankton in biological cladistics. I wonder, do you have any
estimates of the degree to which linguistic borrowing takes place?
I would think that English would show lots of borrowing -- but
how much of the modern English vocabularly is French?

Which reminds me, after all the borrowing we've done from French,
you'd think they'd appreciate our efforts at partial repayment,
but they remain incomprehensibly unappreciative.