A friend of mine had the following question, and I figured this would be the best place to ask:

"Do you happen to know why the anaphora of St. John Chrysostom, our father among the saints, looks different depending on whether you're reading a Byzantine text, a Syriac text or an Ethiopian text? I assumed that they would be identical or at least very close; they do, indeed, have similarities between each other but there's also so much extra in each that isn't in the other two! "

Don't you think it might be that Anaphoras were memorized by the clergy rather than them having a Service Book to read? Given the way oral communication is passed, it isn't far off to understand that variations over time and through translations cand and do occur.

Bob

All texts being transcribed in manuscript prior to the invention of moveable type printing, variations gradually slip in due to scribal error (the most common being the omission of a word or even an entire line; or the mis-transcription of a word for a similar-looking one). Over generations of transcriptions, this can lead to separate "families" of manuscripts deriving from different originals; scholars can even derive the relationship of one manuscript to another based on those differences.

Moreover, transportation and communications being what they were for most of the medieval and early modern period, different Orthodox communities had little exchange of information, resulting in a natural "drifting" of usage between Churches. The more isolated the Church, the more idiosyncratic its usage and its text became. So, even within the Greek-speaking Churches, there are differences between Greek, Antiochian and Alexandrian texts.

The translation of the texts into Slavonic for the Slavic Churches did not help matters. Not only were there differences accountable to translation, but also subsequent drift within the Slavonic-using Churches. By the mid-17th century, differences between Greek and Slavonic texts were becoming significant, and this is part of what prompted Patriarch Nikon of Moscow to "reform" the books--though he was in error in thinking that Muscovite usage had diverged from the more "original" Greek usage: in fact, the Russians had retained much more of the original Constantinopolitan rite, while the Greeks had introduced numerous changes since 1453 (most Greek books were in fact being typeset in Venice), so if anything, the Greeks should have amended their books to reflect Russian usage.

Uniformity has never been regarded as a virtue by the Orthodox Churches--Nikon's attempt to impose uniformity from above meeting with about as much success as the Ruthenian Church's attempt to impose the RDL on its faithful (though Ruthenians don't seem as enamored of self-immolation as the Old Ritualists). You will find differences between Churches, between parches within Churches; and even between parishes within eparchies. In general, the books prescribe the minimum that must be done, and allow everybody to decide how much they wish to go beyond that. Not even monasteries (with a few exceptions) perform all the services in their entirety, while cathedrals and parishes redact from monastic usage.