Author's note: these pages were written some years ago. I am not planning to update them. For a more current coverage, see the link to palaeos com Palaeos website (to which many links on these pages point to anyway. More info here


Evolutionary Systematics

Evolutionary Systematics, also called Gradistic Taxonomy, gives an a dynamic evolutionary slant to the static Linnean system.  It is based on a combination of branching and divergence.  Most old books on palaeontology were based on this paradigm.  Evolutionary Systematics was formulated by such "grand old men" of palaeontology as Ernst Mayr and G. G. Simpson.  This approach accepts the Hennigian cladistic methodology as adequate for reconstructing phylogenetic trees, but retains paraphyletic groups (e.g. "Wikipedia link Reptilia").

Also, unlike Cladistics, with it's reliance on a hypothetical Most Recent Common Ancestor that is never actually described or discovered (a missing link that is always missing), Evolutionary systematics gives illustrations of the actual evolution of one species or higher taxon into another (as illustrated by the graphic at the top of the page showing the evolution of fossil horses).

Admitedly, Evolutionary Systematics suffers from a number of shortcomings.  For example the use of several very different criteria (phylogeny, divergence, adaptational level) to define particular taxa, as well as inconsistencies inherent in the paraphyletic approach (e.g. separating Class link to palaeos com Aves (Birds) from the link to palaeos com Archosauria).  This, together with the greater rigour and precion of the and practical and heuristic superiority of the Cladistic (Phylogenetic) approach has meant that over the past decades.Evolutionary Systematics has greatly declined; the result being the rise of cladistics.as the dominant paradigm.

Apart from my own good self I have only found one defense of evolutionary systematics on the Web - a lone voice in the wilderness, which you can check out if you want:  Stanley Friesen explains why I prefer an evolutionary classification.
 
Evolutionary Taxonomy

Fossil Horses in Cyberspace is an excellent site that (among other things) gives a practical example of Evolutionary Systematics (as a methodology for the evolution of fossil horses).  This the site that I got the kewl icon at the top of ths page from.

Why I prefer Evolutionary Systemmatics

Granted Evolutionary Systematics has problems, as does any conceptual system.  But the thing I myself like about it - and here I am talking intuitively rather than scientistically -  is that it is based on two very important intuitive ideas: deep time and metamorphosis.  Deep time means time extending over millions of years.  This is part of the vastness of the universe - the temporal vastness that goes alongside the spatial vastness.  Deep Time provides the theatre for metamorphosis, for the change and transformation of organsims - and indeed of Gaia and the universe as a  whole - over time.  I think of organisms changing through time - one evolving into the next - like one of those time-lapse films of plants growing.  We can't see plants growing - it is too slow.  But if things were speeded up the astonishing metamorphosis would be visible.  It's the same with evolution.  Evolutionary systemmatics is a means of describing this process.


"Vertical" and "Horizontal" Classification



Systematics
Systematics


page history

page uploaded 13 November 1998
revised 27 November