Biol 324 Introduction To Seed Plant Taxonomy
The Phylocode
How do we turn a phylogenetic tree into taxa?
An evolutionary tree determines GROUPING but not RANKING (a human construct).
We can either:
(1) Modify Linnaean taxonomy to make sure taxa at all ranks are strictly monophyletic, while disturbing the traditional rank-based classification as little as possible. This is the method used by most taxonomists and is consistent with the botanical code of nomenclature (ICBN) and the zoological code (ICZN).
(2) Abandon ranks altogether and just have a series of RANK-FREE nested taxa. This method is used by supporters of the phylocode.
How important are ranks?
Ranks (genera, families, orders etc) may have no biological reality but they are useful anchor-points for teaching, learning and information transfer. Proponents of a rank-free taxonomy argue that ranks can be positively misleading.
The official site of the Phylocode is:
http://www.ohio.edu/phylocode/
Other sites:
ICBN
http://www.iapt-taxon.org/nomen/main.php
ICZN
http://iczn.org