--- In cybalist@..., Paul Alesu <rpales@...> wrote:
>
> Question about rules:
>
> Let's assume that a language B develops from language A over 2000
years
> following a set of transformation rules AtoB. Independently, a
second
> language C develops from the same language A over 4000 years
following a
> set of transformation rules AtoC.
>
> A ->-> (AtoB) ->->B
> A ->-> -> -> -> -> (AtoC) ->->->->->->C
>
> Due to lack of written and archeological resources we make the
honest
> mistake to believe that the development followed the sequence
>
> A ->-> (AtoB) ->->B -> -> (BtoC) ->->C
>
> where BtoC is the erroneously perceived rule which in reality is the
> difference AtoC-AtoB.
>
> Does any linguistic method exist to help us detect this kind of
errors?
I believe the biggest indicator of such a problem would be the rules
needed to reverse phoneme mergers or other losses of contrast.
Changes undoing earlier changes can hint at a problem, but such
changes can occur. The prothetic vowel came and went between Latin
and Italian, and we can add the example of Guto Rhys's Welsh dialect
where at least some of the prothetic vowels have been dropped. They
would show up as 'sporadic' changes or weirdly conditioned changes.
There would also be many unresolved problems in the evolution.
There have been similar cases in the past, and the problems have come
to light:
1. Sanskrit as the ancestor of all the other IE languages. Not
entirely similar, as language A is unknown.
2. Sanskrit as the ancestor of the Indic languages.
3. Gothic as the ancestor of the Germanic languages.
4. Classical Latin as the ancestor of the Romance languages. I am
not sure how much Vulgar Latin has been usefully documented by
private inscriptions and the like.
I suspect there may have been a similar story with (West Saxon) Old
English and Modern English. However Anglian Old English is sparsely
documented.
Only the first case has time scales similar to your example.
However, I think glottochronology can actually give useful results in
the case that has inspired the question. The dates it gives may be
unreliable, but I believe they give a useable measure of
relatedness. I quote the dates given in Renfrew's book on IE
origins; the dates appear to come from Rea, 1973. French and Italian
split in 1586, as did Spanish and Portuguese. Romanian and Italian
split in 1130. I think 1130 AD for 2000 BC (or even much earlier)
would be an amazing error.
Richard.