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Organisms
Diversity & Evolution 2 (2002) Electronic Supplement 4 |
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Hans-Christian Schaefer, Miguel Vences, Michael Veith:
Molecular
phylogeny of Malagasy poison frogs, genus Mantella (Anura: Mantellidae):
homoplastic evolution of colour pattern in aposematic amphibians.
print version: Org. Divers. Evol. 2(2): 109-117. 2002 (full article)
electr.
suppl.:
Part 1. Colour pictures of investigated frogs.
pdf-format, 860 KB
Part 2. NEXUS-file for
phylogenetic analysis. txt-format, 60
KB
Abstract:
We studied the evolution of colour pattern in
Malagasy poison frogs, genus Mantella, a group of diurnal and toxic frogs
endemic to Madagascar. Based on a phylogeny reconstructed using 1130 bp of the
mitochondrial 16S rRNA gene, the genus can be divided into five species groups.
Within some of these groups, inter-specific genetic divergences were very low
(1.2 - 2.8% sequence divergence) while colour patterns were markedly different.
In contrast, Mantella madagascariensis and M. baroni, two species
which show extremely similar dorsal coloration patterns, were not included in
the same clade. This conclusion was supported by high bootstrap values and by
significant rejection of alternative topologies using KH-tests. Analysis of
colour patterns and tentative reconstruction of ancestral states yielded five
character states shared by these two species but not by their respective sister
species, M. aurantiaca and M. nigricans. Considering these
detailed similarities as symplesiomorphic therefore requires the assumption of
multiple reversals in other species, whereas a homoplastic colour evolution in
the sympatric M. madagascariensis and M. baroni appears as most
parsimonious. This parallelism may have been triggered by Müllerian
mimicry. However, additional data is necessary to support this
hypothesis.
Key words: Amphibia, Mantellidae, Madagascar, 16S rRNA,
phylogeny, aposematism, mimicry
Figures:
A. Mantella cowani group
B. Mantella madagascariensis group
Fig. 5: Mantella
madagascariensis
C. Mantella bernhardi group
D. Mantella betsileo group
E. Mantella laevigata group