Genomic Lorem Ipsum

I was thinking about this Lorem Ipsum text the other day (see my post here, or a few entries down the page) and it occurred to me that there was something oddly genetic about the whole thing. Here is a message that has lost its intrinsic meaning, but nevertheless continues to get handed down from typesetter to typesetter like junk DNA. Geneticists have tools to measure these things, and they can often deduce how long two species have been separated by the genomic “distance” between them.

Why not, I thought, use the tools of a geneticist on this homely passage? If you want to compare two passages, be they poetry or protein, the tool of the trade is the Needleman-Wunsch algorithm. It finds the best sequence alignment between the two and returns a score. Starting with the two texts (CICERO for the original and IPSUM for the latter day corruption) we perform a little algorithmic MATLAB mojo and arrive at the following alignment.

CICERO: Neque porro quisquam est, qui dolorem ipsum q
                                         ::::::::::  
IPSUM:  --------------------------------Lorem ipsum--


CICERO: uia dolor sit amet, consectetu-r, adipisci-- 
           ::::::::::::::::::::::::::: : :::::::::  :
IPSUM:  --- dolor sit amet, consectetuer- adipiscing 


CICERO: velit, sed quia- non numquam- ei----u-s modi 
         ::::::::::  :: :::  :::   : : :    : : ::: :
IPSUM:  -elit, sed -diam no--num---my nibh euis-mod- 


CICERO: tempora incidunt ut labore et dolore magnam a
        :       :::::::::::::: ::: ::::::::::::::: ::
IPSUM:  t-------incidunt ut la-ore-et dolore magna- a


CICERO: liquam quaerat volupt-atem
        :::::::   ::::::::: : ::  
IPSUM:  liquam ---erat volu-tpat--

That gives us a total of 44 letter mutations (gaps and changes) out of a 173 letter message. If we assume a relatively speedy mutation drift rate of 10-8 per letter per generation, and we further assume that a typesetter generation is 20 years, we can work out that Cicero’s original oration occurred 508 million years ago, which places it neatly at the end of the extraordinarily fertile Cambrian period. I understand that Cicero was huge with the trilobite crowd.

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