Interested in this paper? Please contact Pat Hutchings,
path at amsg.austmus.gov.au (PatH), who will have available reprints of the
following recently-published contribution to the annelid phylogeny debate.
Note: Comment to the list are welcome, but DO NOT SEND REPRINT
REQUESTS to the list (or to me). Thanks, - GBR.
Brown, S., G. Rouse, P. Hutchings, & D. Colgan. 1999. Assessing the
usefulness of histone H3, U2 snRNA and 28S rDNA in analyses of
polychaete relationships. -- Australian Journal of Zoology, 47(5):499-516.
ABSTRACT:
"DNA sequence data from for histone H3 (34 species), U2 snRNA (34
species) and two segments (D1 and D9-10 expansion regions) of 28S
rDNA (28 and 26 species, respectively) have been collected to investigate
the relationships of polychaetes. Representatives of all of the major
morphologically identified clades were used, as well as members of the
Sipuncula, Echiura, Turbellaria, Clitellata and Siboglinidae (formerly the
phyla Pogonophora and Vestimentifera). Maximum parsimony analyses of
the separate data sets gave conflicting results and none conformed closely
to previous results based on morphology. Instead each data set provided
corroboration of a few of the morphological groupings, usually pairing,
though inconsistently, members of the same family. Higher groupings
proposed on morphological grounds were rarely recovered. Maximum
parsimony analysis of the combined data, excluding areas of uncertain
alignment, recovered some morphological groupings such as Cirratulidae,
Terebellidae, scale worms and eunicimorphs, and did not significantly
contradict others. However, some expected groupings were not recovered.
Surprisingly, the fanworms (Sabellidae and Serpulidae) were not shown as
sister taxa, and monophyly of Phyllodocida, a morphologically well
corroborated clade, required four more steps than most parsimonious
trees. Aciculata was not seen in our analyses, although it was the most
strongly supported large clade in Rouse and Fauchald (1997, Cladistics
and polychaetes. Zoologica Scripta 26, 138-204). Trees constrained to
show Aciculata as monophyletic were 18 steps longer than the most
parsimonious trees. If trees are rooted on sipunculans rather than the
nematode, Aciculata is nearly recovered, being rendered paraphyletic by
the inclusion of the sister-pair of Oweniidae and Chaetopteridae. As
suggested by some recent morphological and molecular analyses,
Siboglinidae and Clitellata may well have sister groups among polychaetes.
The morphologically aberrant Sternaspidae are closest to members of
Terebellida in the present analyses, supporting the placement of Rouse and
Fauchald. Interesting results deserving further assessment concern the
placement of Chaetopteridae, Oweniidae and Sipuncula.
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