The successful categorisation of exomorphs into suitable taxa is on a level of difficulty approaching the impossible. Life on Earth itself is so complex that even now, a thousand years after the discovery of DNA, periodic reassessments remain necessary. The attempt, therefore, to impose the standard system of biological classification on lifeforms whose biochemistry bears little or no similarity to our own is one that would seem doomed to fairly almost from the start. Furthermore, we have little beyond the most rudimentary knowledge of the bio- and ecosphere in which the species evolved, and no information at all about the process of their evolution.
Dr. Hiram Namas,
Argon Federation Polytechnic Institute
From X4 encycopedia