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2004], but current data place it between clade I and clade II [strong support from multiple nuclear genes, K. Barker unpublished data])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

 

 

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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."