  Tools that effectively analyze and compare sequences are of great importance
in various areas of applied computational research, especially in the framework
of molecular biology. In the present paper, we introduce simple geometric
criteria based on the notion of string linearity and use them to compare DNA
sequences of various organisms, as well as to distinguish them from random
sequences. Our experiments reveal a significant difference between biosequences
and random sequences - the former having much higher deviation from linearity
than the latter - as well as a general trend of increasing deviation from
linearity between primitive and biologically complex organisms.
