----- Original Message -----
From: "H.M. Hubey" <hubeyh@...>
To: <Nostratica@yahoogroups.com>
Sent: Friday, February 21, 2003 11:24 PM
Subject: Re: [Nostratica] Proto-Celtic



> If languages change at different rates, then some of the present-day languages could actually be aunts, or grand-aunts of others instead of being sisters. Is that not logical?

Sort of, to the extent that human-family-based metaphors are applicable to cladistic models. Technically, we speak of "sisterhood" between taxa A and B if A and B have the same _immediate_ ancestor, that is when the last common ancestor of A and B split into A and B and nothing else:

Proto-AB --+--A
|
`--B

A and B may be atomic taxa ("languages") or clades("branches").

Piotr