Proposal
(119) to South
American Classification Committee
Change
linear sequence of genera in the Troglodytidae
Effect on South American CL: This rearrange the sequence of genera in the
Troglodytidae to conform to recent genetic data on their phylogeny.
Background: Our
linear sequence of genera in the Troglodytidae is maintained largely through
historical momentum from the last 40 years. Early in the 1900s (e.g., Ridgway),
the sequence tended to begin with Cistothorus
and Thryothorus. In the mid-1900s,
sequences tended to lead with Troglodytes.
Starting with Paynter's (1960) Peters Checklist, the sequence began with Campylorhynchus
and ended with Cyphorhinus. Paynter's sequence received input from
Selander, who was studying Campylorhynchus at the time, but I cannot find
any explicit rationale for that sequence or any other sequence.
New information: Barker
(2004) analyzed sequence data from mt DNA (cytochrome b) and nuclear DNA
(intron 4 of beta fibrinogen) from most genera in the Troglodytidae.
Get a pdf of Barker (2004) at:
http://www.tc.umn.edu/~barke042/pdfs/Barker04.pdf
Barker found strong support (Fig. 3
+ 4) for two major clades, and a number of subgroups:
I. First major clade:
Microcerculus + Salpinctes +
Catherpes + Hylorchilus (note: root of the wren tree was
tentatively thought to be between Salpinctes and other wrens [Barker,
2004], but current data place it between clade I and clade II [strong support
from multiple nuclear genes, K. Barker unpublished data])
II. Second major clade:
(a) Odontorchilus
(b) Troglodytes + Cistothorus
(c) Campylorhynchus +
Thryomanes +Thryothorus +Henicorhina + Cyphorhinus + Cinnycerthia
other branches with strong
support:
(d) Campylorhynchus + (Thryomanes
+Thryothorus ludovicianus)
(e) Henicorhina +
Cyphorhinus + Cinnycerthia + other Thryothorus
Thryothorus is
polyphyletic, but insufficient taxon-sampling prevents further rearrangement
and presumed revival of Thryophilus at this time.
Analysis: Although
additional, ongoing sampling by Keith will likely produce some further changes
in the branching pattern, it's clear that our current linear sequence does not
reflect phylogeny in the family.
Keith and I propose the following
linear sequence (South America genera only) to best reflect historical
relationships among genera. Other permutations are, of course, possible, but
this one minimizes disturbance of the historical sequence.
Microcerculus
Odontorchilus
Troglodytes
Cistothorus
Campylorhynchus
Thryothorus
Cinnycerthia
Henicorhina
Cyphorhinus
Regardless of whatever future
adjustments we need to make, this one is supported by genetic data, in contrast
to the traditional sequence, which lacks any explicit justification. This
proposal sailed through the South American Checklist Committee with little
comment, but that might at least in part be due to fewer wren genera there,
particularly the absence of Uropsila and Hylorchilus, missing
taxa in Keith's sample.
Recommendation: I see no
reason to perpetuate a misleading classification any longer, and I think the
only reasons not to vote YES would be to wait for greater taxon-sampling,
especially within Thryothorus.
Literature Cited:
BARKER, F. K. 2004. Monophyly and
relationships of wrens (Aves: Troglodytidae): a congruence analysis of
heterogeneous mitochondrial and nuclear DNA sequence data. Molecular
Phylogenetics and Evolution 32: 486-504.
Van Remsen,
April 2004, with input and comments from Keith Barker
_____________________________________________________________________________________
Comments from Nores: "SI estoy de acuerdo, ya que los resultados
provenientes de dos tipos de análisis genéticos coinciden. El único cambio que yo
haría a la secuencia sería poner Cinnycerthia antes que Thryothorus
y no entre medio de Thryothorus y Henicorhina. Me parece que Thryothorus
y Henicorhina son muy afines como para separarlos con un género que
aparentemente no es tan afín."