“…While such an approach has been proposed [Brendel and Busse, 1984], most investigations along these lines have used grammar formalisms as tools for what are essentially information-theoretic studies [Ebeling and Jimenez-Montano, 1980;Jimenez-Montano, 1984], or have involved statistical analyses at the level of vocabularies (reflecting a more traditional notion of comparative linguistics) [Brendel et al, 1986;Pevzner et al, 1989a,b;Pietrokovski et al, 1990]. Only very recently have generative grammars for their own sake been viewed as models of biological phenomena such as gene regulation [ColladoVides, 1989a[ColladoVides, ,b, 1991a, gene structure and expression [Searls, 1988], recombination [Head, 1987] and other forms of mutation and rearrangement [Searls, 1989a], conformation of macromolecules [Searls, 1989a], and in particular as the basis for computational analysis of sequence data [Searls, 1989b;Searls and Liebowitz, 1990;Searls and Noordewier, 1991].…”