Should we ditch infageneric ranks?
K.Thiele at CBIT.UQ.EDU.AU
Tue Sep 27 02:08:55 CDT 2005
A colleague and I are preparing a paper to merge two Australian proteaceous
genera (Dryandra, 93 spp and Banksia, 80 spp). Morphological and molecular
results provide strong evidence that the latter is paraphyletic with respect
to the former.
Both genera have a rich infrageneric taxonomy (subgenera, sections, series,
subseries), mostly produced in the last 25 years.
We are considering two options:
1. Maintain and update the infrageneric taxonomy. To do this, we would need
to do stat. novs for over half the subgeneric taxa (e.g. from series to
section, from subgenus to section, from section to series). The result would
be an equally rich infrageneric classification, but with many rank changes.
2. Simply ditch the infrageneric classification, and instead create informal
species groups and refer people to the cladograms for a full understanding
of relationships within the new genus. The thinking here is that infraranks
in the past were introduced mainly to capture previous workers' hypotheses
of relationships - which are better represented in the new cladograms than
in formally ranked taxa anyway. So why maintain the infrageneric
Both these courses of action have advantages and disadvantages. The choice
is basically about the role of richly ranked classifications (particularly
infraranks) in the age of cladistics. Option 2 perhaps represents a
compromise between conventional texonomy and the phylocodists - maintain the
core Linnaean ranks (genus, family etc) for their utility but ditch
infraranks where possible.
We are keen to poll TAXACOM members as to their opinions on these two
alternative courses of action - what do you think we should do?
Cheers - Kevin Thiele
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