A "shallow phylogeny" of shallow barnacles (chthamalus).
BACKGROUND
We present a multi-locus phylogenetic analysis of the shallow water (high intertidal) barnacle genus Chthamalus, focusing on member species in the western hemisphere. Understanding the phylogeny of this group improves interpretation of classical ecological work on competition, distributional changes associated with climate change, and the morphological evolution of complex cirripede phenotypes.


RESULTS
We use traditional and Bayesian phylogenetic and 'deep coalescent' approaches to identify a phylogeny that supports the monophyly of the mostly American 'fissus group' of Chthamalus, but that also supports a need for taxonomic revision of Chthamalus and Microeuraphia. Two deep phylogeographic breaks were also found within the range of two tropical American taxa (C. angustitergum and C. southwardorum) as well.


CONCLUSIONS
Our data, which include two novel gene regions for phylogenetic analysis of cirripedes, suggest that much more evaluation of the morphological evolutionary history and taxonomy of Chthamalid barnacles is necessary. These data and associated analyses also indicate that the radiation of species in the late Pliocene and Pleistocene was very rapid, and may provide new insights toward speciation via transient allopatry or ecological barriers.
Department of Genetics, University of Georgia, Athens, Georgia, United States of America. jpwares@uga.edu
John P
JP
Wares
M Sabrina
MS
Pankey
Fabio
F
Pitombo
Liza Gómez
LG
Daglio
Yair
Y
Achituv
D000818:Animals; D001499:Bayes Theorem; D019143:Evolution, Molecular; D010802:Phylogeny; D016133:Polymerase Chain Reaction; D001468:Thoracica / Q000145:classification* / Q000235:genetics