Darwin-L Message Log 2:79 (October 1993)

Academic Discussion on the History and Theory of the Historical Sciences

This is one message from the Archives of Darwin-L (1993–1997), a professional discussion group on the history and theory of the historical sciences.

Note: Additional publications on evolution and the historical sciences by the Darwin-L list owner are available on SSRN.

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<2:79>From DARWIN@iris.uncg.edu  Wed Oct 13 22:17:16 1993

Date: Wed, 13 Oct 1993 23:24:08 -0400 (EDT)
From: DARWIN@iris.uncg.edu
Subject: Some clarifications re: textual transmission
To: darwin-l@ukanaix.cc.ukans.edu
Organization: University of NC at Greensboro

A few messages ago John Langdon expressed discomfort with the notion of
"ploidy" as applied to manuscripts.  I think this really is fairly close to
the actual case in some texts, and provide here a simple contrived example
by way of illustration (this example could easily be expanded to include
various details of manuscript transmsssion not mentioned here).

The situation begins with some ancestral manuscript (one physical object)
which existed in the past.  That text was duplicated by hand, the original
was lost, more copies were made of the copies, and so on, over hundreds of
years.  What we have today might be, say, twenty copies of the text all of
which differ at various points due to copying errors.  At one particular
line in the text one of the extant copies might read:

   From experiment I know this to be true.

Another one of the copies of the text might look like this at the line in
question:

   From experience I know this to be true.

But a third copy of the text might actually carry both readings, with one
stuck in the space between the lines or added as a note in the margin.

    experience
   From experiment I know this to be true.

Thus there is polymorphism in the whole collection of manuscripts, since
some read "experiment" at the locus in question, and others "experience";
but there are also individual manuscripts, like the third one here, that
are themselves polymorphic.  It seems reasonable in a loose sort of way to
speak of manuscript three above as being "diploid" at the locus in question
-- two readings are present and they differ, making that individual
polymorphic.  Indeed, if you examine a good edition of the Bible (one
ancient text that people other than philologists often have around) you
will see an example of a modern printed edition that carries such multiple
readings (alleles) for a number of loci: one reading in the main body of
the text and another in the notes (what text scholars call "the critical
apparatus") at the bottom of the page.

A scribe copying manuscript three above might copy it as it is, preserving
the polymorphism, or that scribe might omit one or the other of the
variants in the transcription making the new copy monomorphic (and
haploid).  One of the points I think Jeff Wills was making was that
manuscripts were often copied by a group of scribes listening to someone
read the text aloud.  The reader would be more likely to read through such
a polymorphism speaking only one of the variants, and the copyists might
never know that the exemplar was polymorphic.  Another copyist, working
visually with the exemplar in front of him, would see both variants and
perhaps be more likely to copy them both.  This would contrast with the
case of most genetic polymorphisms in evolutionary biology where the
probability of transmitting either of two alleles (variant chromosomal
readings) is ordinarily equal, except in unusual cases where there is
"meiotic drive" as Greg Mayer mentioned.  The copying situation where the
exemplar was being read aloud, and the reader was systematically ignoring
marginal or interlinear variants, would be somewhat akin to meiotic drive.

Different mechanisms of copying may lead to different types of errors.  If
one is copying visually there are certain errors that are easy to make:
confusing "rn" and "m" for example; these are "errors of the eye". If one
is copying by listening to a reader it is easier to make "errors of the
ear": confusing "weigh" and "way", for example.  Manuscript scholars have
developed fairly sophisticated classifications of error types; I'll see
if I can find a copy of one and post it.  It would be interesting to
compare these to the types of errors one finds in DNA replication, for
example.

And while it is easy to see the parallel between text sequences and DNA
sequences, I want also to mention (since my own background is in gross
morphology rather than molecular morphology) that the copying history of
manuscripts may also be reconstructed in some cases using evidence that is
more akin to gross morphology than DNA sequences.  The transmission history
of geographical maps drawn by hand, for example, may be reconstructed by
examining the presence or absence of whole objects (map objects), the
positions of such objects, and so on.  The transmitted entity here is just
not linearly structured.

A couple of references that might be of use to non-specialists interested
in the manuscript situation are:

Cameron, H. Don.  1987.  The upside-down cladogram: problems in manuscript
affiliation.  Pp. 227-242 in: Biological Metaphor and Cladistic Classifica-
tion: An Interdisciplinary Prespective (H. M. Hoenigswald & L. F. Wiener,
eds.). Philadelphia: University of Pennsylvania Press.

Reynolds, L. D., & N. G. Wilson.  1991.  Scribes and Scholars: A Guide to
the Transmission of Greek and Latin Literature, third edition.  Oxford:
Clarendon Press.  (Chapter 6 in particular)

Bob O'Hara, Darwin-L list owner

Robert J. O'Hara (darwin@iris.uncg.edu)
Center for Critical Inquiry and Department of Biology
100 Foust Building, University of North Carolina at Greensboro
Greensboro, North Carolina 27412 U.S.A.

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