From: Richard Wordingham
Message: 24137
Date: 2003-07-04
--- In cybalist@yahoogroups.com, Juha Savolainen <juhavs@...> wrote:
>
> Richard,
>
> Hmmm...I think I must disagree with you. First, my point about
the "core words" is based on my understanding (faulty as it may be)
that Swadesh did not claim that all words change at a constant rate.
Rather, if my memory serves me well here, Swadesh claimed that
the "core words" changed at a constant rate.
Is this indeed so, or is it a folk tale or misintepreted mathematical
simplification?
> If so, it is upon a defender of such a view to show that such "core
words" can be unproblematically identified. If not, the whole
exercise becomes rather pointless as no non-arbitrary "lexical
clocks" can be put together.
If different meanings have different replacement rates, these
retention rates can be estimated by large scale studies. There have
been large scale studies of Austronesian and Indo-European. The
Austronesian stude very clearly demonstrated that the meanings have
different results. One could get a reasonable fit for most meanings
by chopping them into four or five groups by replacement rates and
assinging constant replacement rates to the all but the most
conserved group. In the most conserved group (which I think
includes 'I', 'you', 'two', 'five', 'louse'), the variations in
replacement rates were statistically significant. Thus you need a
computer and not a pocket calculator to do your own
glottochonological calculations.
> As for the "molecular clocks": there is a world of difference
between evolution driven by natural selection and evolution driven by
random accumulation of copying errors. I claim that only the latter
give us some realistic hope of constructing meaningful "molecular
clocks" and fail to understand what the compensating "error terms"
could be here. Of course, certain bases are more prone to replacement
than others, but this is not an obstacle in itself (although it makes
more difficult the construction of molecular clocks as the rate of
change must be studied case by case). What does count is the
selective neutrality of the evolution. And unless you spell out how
the "error termr" lay rest the (chronologywise) disturbing selective
forces in (a) genetic evolution and (b) memetic evolution, I am still
asking what might play the role of "junk genes" in memetic evolution.
Evolution matters when dating the separation of two DNA lineages
because it may preserve some subsequences and hasten change in
others. I suppose to some extent this is analogous to variations in
the 'tempo of linguistic change'.
The error to be corrected is that different words for the same
meaning may have different retention rates. Effectively, the
retention rate for a meaning could itself be a random variable. For
a comparison of two languages this is not an insuperable problem
(though the calculations to be done begin to look quite fearsome),
though it may significantly complicate the analysis of a whole
cluster of languages.
> And I did hope that my Keynesian joke would give some insight on my
views: of course, if you take a very Olympian view of a river, you
will "compensate away" the turbulences. But such an "Olympian clock"
would permit margins of errors that are unacceptable for dating
purposes.
The margins of error quoted in the New York Times were quite large.
Richard.