Proposal (291) to South American Classification Committee
Change
linear sequence in Tangara
Effect on SACC: All that this would do is change the linear
order of species in Tangara to reflect published data.
Background and New information: The current linear
sequence is essentially unchanged from Storer's sequence in the Peters
checklist and is maintained largely by historical momentum rather than explicit
rationale:
Current SACC sequence =
Tangara inornata
Tangara palmeri
Tangara mexicana
Tangara chilensis
Tangara fastuosa
Tangara seledon
Tangara cyanocephala
Tangara desmaresti
Tangara cyanoventris
Tangara johannae
Tangara schrankii
Tangara florida
Tangara arthus
Tangara icterocephala
Tangara xanthocephala
Tangara chrysotis
Tangara parzudakii
Tangara xanthogastra
Tangara punctata
Tangara guttata
Tangara varia
Tangara rufigula
Tangara gyrola
Tangara lavinia
Tangara cayana
Tangara vitriolina
Tangara meyerdeschauenseei
Tangara peruviana
Tangara preciosa
Tangara rufigenis
Tangara ruficervix
Tangara labradorides
Tangara cyanotis
Tangara cyanicollis
Tangara larvata
Tangara nigrocincta
Tangara nigroviridis
Tangara vassorii
Tangara heinei
Tangara phillipsi
Tangara viridicollis
Tangara argyrofenges
Tangara cyanoptera
Tangara velia
Tangara callophrys
Burns & Naoki (2004) sequenced about 1500 bps of two
mitochondrial genes, cytb and ND2, for 43 of 49 species of Tangara.
Their hypothesis of relationships within Tangara (their Fig.
2) contains about 23 nodes with 97-100% Bayesian support that involved more
than 1 species. To incorporate that information on sister relationships into
our classification, we have produced the following sequence, using the
conventions of basal taxa listed first and allotaxa listed NW to SE. Otherwise,
we then incorporated the remaining topology of their Fig. 2, but maintained
historical stability wherever possible.
Tangara ruficervix
Tangara cyanoptera
Tangara viridicollis
Tangara heinei
Tangara argyrofenges
Tangara phillipsi [not sampled]
Tangara palmeri
Tangara
peruviana [not sampled but almost certainly sister to peruviana]
Tangara
preciosa [not sampled in original study but unpublished Burns data
support this placement]
Tangara
meyerdeschauenseei
Tangara
cayana
Tangara
vitriolina
Tangara
nigrocincta
Tangara
larvata
Tangara
cyanicollis
Tangara
varia
Tangara
rufigula
Tangara
guttata
Tangara
xanthogastra
Tangara
punctata
Tangara
vassorii
Tangara
nigroviridis
Tangara
labradorides
Tangara
cyanotis
Tangara
inornata
Tangara
mexicana
Tangara
chilensis
Tangara
velia
Tangara
callophrys
Tangara
seledon
Tangara
fastuosa
Tangara
cyanocephala
Tangara
desmaresti
Tangara
cyanoventris [not sampled in original study but unpublished Burns data
support this placement]
Tangara
lavinia
Tangara
gyrola
Tangara
rufigenis [not sampled; placed here tentatively following Isler & Isler
1989]
Tangara
chrysotis
Tangara
xanthocephala
Tangara
parzudakii
Tangara
schrankii
Tangara
johannae
Tangara
arthus
Tangara
florida
Tangara
icterocephala
Some of this sequence will likely require tweaking with additional
analyses, although Burns's unpublished data with more taxa and sequences
strongly supports the suggested sequence.
Recommendation: Yes. Regardless of any future tweaking, the
above sequence reflects published data, whereas the traditional one does not.
References (I have pdf if you need it):
BURNS, K. J., AND K. NAOKI. 2004. Molecular
phylogenetics and biogeography of Neotropical tanagers in the genus Tangara. Molecular Phylogenetics and Evolution 32:
838-854.
Van
Remsen & Kevin Burns, June 2007
______________________________________________________________________________________________________
Comments from Zimmer: "YES. Even if modifications
are needed, this represents a distinct step forward."
Comments from Nores: "YES, aunque mirando el árbol de Burns y Naoki (2004) no me resulta tan claro
como fue finalmente logrado el ordenamiento. De todos modos, parece que es un
buen avance comparado con la tradicional secuencia."
Comments from Stotz: "NO. Given that Kevin Burns
was involved in creating this proposal, perhaps it is a bit hard to fathom that
I am voting against it because of further data from Kevin. I feel this is
similar to the Hemispingus case, where more data is indicating
that there are broader issues that remain to be dealt with. In this
case Tangara is not monophyletic, and given the limited
information that is contained within the order of taxa in a large genus like Tangara,
I would prefer to wait until the more complete dataset is available."
Comments from Stiles: "YES. The proposal best
reflects the phylogenetic evidence available. I may be myopic, but I fail to
understand Doug's objection here. The branch to Tangara in the
Burns & Naoki paper has 100% Bayesian support in both trees, and it leads
only to Tangara (no putative Tangara species on
other branches, no non-Tangara on the Tangara branch;
there are evidently several major clades within Tangara, but this
does not affect the monophyly of the genus)."
Comments from Jaramillo: "YES - Even if refinements
are needed in the future, the new order will be easier to work with than our
present order. This applies to events such as the need to divide Tangara to
maintain monophyly, or the addition of other species into Tangara
... whatever may arise with further sampling of tanagers (reading
between the lines of Doug Stotz's comments)."
Comments from Kevin Burns: "Doug is correct that our new data show that six species of Thraupis
are imbedded within Tangara. Thus, Tangara is not
monophyletic. These data are strongly supported with nuclear and mtDNA data.
So, when our results are published, these species will need to be moved within
the sequence. But note that Al Jaramillo is correct in his comments in
that this wouldn't result in rearrangement of all the Tangara. These Thraupis species
would simply be inserted as a group within the sequence (most likely between larvata and
guttata in the above arrangement).
"Hemispingus is a different story. In that case, the nonmonophyly
of Hemispingus is the result of multiple species being inserted at
multiple places within Hemispingus."