----- Original Message -----
From: "H.M. Hubey" <hubeyh@...>
To: <Nostratica@yahoogroups.com>
Sent: Saturday, February 22, 2003 12:09 AM
Subject: Re: [Nostratica] Proto-Celtic



>
> Proto-AB --+--A
> |
> `--B
>
> What if A is still identical to AB and that it was only B that innovated and branched off? It seems we should
> correct the model.

This (no change at all in one of the branches) is unlikely to happen in practice, but even if it did happen, a split is a split even if one of the descendent languages is identical with the parent (or, more realistically, very similar to it). A, like B, is _later_ than Proto-AB, no matter how similar they are. The diagram shows phylogenetic relations between taxa and is not intended to reflect their overall similarity.

A language may differ from "itself", i.e. from any of its different chronological "stages". If X is a language evolving anagenetically (i.e. changing but not splitting), we normally use a single label for all its stages, just adding prefixes or adjectives like "Pre-X", "Old X", "Middle X" or "Modern X" for the sake of practical convenience (of course in reality such stages grade into one another and there are no natural boundaries between them).

Piotr