Please look at the best model (with the fewest) contact edges obtained
by CPHL
(Fig 12, p. 22) below and read
<
http://www.cs.rice.edu/~nakhleh/Papers/81.2nakhleh.pdf>
section 2.4 below:
<
http://koenraadelst.voiceofdharma.com/articles/aid/keaitlin1.html>
"Gamkrelidze and Ivanov (1995:348-350) have built an impressive
reconstruction of such successive migrations on an impressive survey
of the linguistic material. To summarize:
1) Initially, there was a single PIE language.
2) The first division of PIE yielded two dialect groups, which will be
called A and B. Originally they co-existed in the same area, and
influenced each other, but geographical separation put an end to this
interaction.
3) In zone A, one dialect split off, probably by geographical
separation (whether it was its own speakers or those of the other
dialects who emigrated from the Urheimat, is not yet at issue), and
went on to develop separately and become Anatolian.
4) The remainder of the A group acquired the distinctive
characteristics of the Tocharo-Italo-Celtic subgroup.
5) While the A remainder differentiated into Italo-Celtic and
Tokharic, the B group differentiated into a "northern" or
Balto-Slavic-Germanic and a "southern" or Greek-Armenian-Aryan group;
note that the kentum/satem divide only affects the B group, and does
not come in the way of other and more important isoglosses
distinguishing the northern group (with kentum Germanic and
predominantly satem Baltic and Slavic) from the southern group (with
kentum Greek and satem Armenian and Aryan)."
end quote
Germanic oscillates just like it is supposed to assuming a South Asian
homeland. Elst's Group A would be far right in Fig 12 and Group B far
left.
M. Kelkar