Phylogeny of Medusozoa and the evolution of cnidarian life cycles

@article{Collins2002PhylogenyOM,
  title={Phylogeny of Medusozoa and the evolution of cnidarian life cycles},
  author={Allen Gilbert Collins},
  journal={Journal of Evolutionary Biology},
  year={2002},
  volume={15}
}
  • A. Collins
  • Published 1 May 2002
  • Biology
  • Journal of Evolutionary Biology
To investigate the evolution of cnidarian life cycles, data from the small subunit of the ribosome are used to derive a phylogenetic hypothesis for Medusozoa. These data indicate that Cnidaria is monophyletic and composed of Anthozoa and Medusozoa. While Cubozoa and Hydrozoa are well supported clades, Scyphozoa appears to be paraphyletic. Stauromedusae is possibly the sister group of either Cubozoa or all other medusozoans. The phylogenetic results suggest that: the polyp probably preceded the… 
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315 Citations
Highly Influential Citations
44
Background Citations
174
Methods Citations
22
Results Citations
20

315 Citations

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Solution to the phylogenetic enigma of Tetraplatia, a worm-shaped cnidarian

Data presented here from the large and small subunits of the nuclear ribosome leave little doubt that Tetraplatia is in fact a hydrozoan genus, and its precise phylogenetic position is within Narcomedusae, as some authors had previously deduced based on structural characters.
...

References

SHOWING 1-10 OF 86 REFERENCES

The demise of a phylum of protists: phylogeny of Myxozoa and other parasitic cnidaria.

Reassessment of myxozoans as metazoans reveals terminal differentiation, typical metazoan cellular junctions, and collagen production, and it is recommended that the group as a whole be removed from all protistan classifications and placed in a more comprehensive cnidarian system.

Towards understanding the phylogenetic history of Hydrozoa: Hypothesis testing with 18S gene sequence data*

Parsimony analyses of two datasets that include the new 18S sequences are used to assess the relative strengths and weaknesses of a list of phylogenetic hypotheses that deal with Hydrozoa, and the monophyly of HydrozoA is strongly supported.

Evaluating multiple alternative hypotheses for the origin of Bilateria: an analysis of 18S rRNA molecular evidence.

  • A. Collins
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1998
Six alternative hypotheses for the phylogenetic origin of Bilateria are evaluated by using complete 18S rRNA gene sequences for 52 taxa to suggest that there is little support for three of these hypotheses, but one is most strongly supported.

A new perspective on lower metazoan relationships from 18S rDNA sequences.

While sequencing additional lineages to identify slowly evolving taxa, the number of complete or nearly complete 18S rDNA sequences for the major diploblastic lineages was increased and the maximum-likelihood framework was used to choose a model which best explains the data.

Evolution and taxonomy in capitate hydroids and medusae (Cnidaria: Hydrozoa)

In those families where the reduction of the medusa can be analysed, it is shown that the reduction occurred after all synapomorphies defining the genera had evolved and usually affected individual species within a genus rather than the original species from which the other species in the genus evolved.

Animal phylogeny and the ancestry of bilaterians: inferences from morphology and 18S rDNA gene sequences

Because chaetognaths and lophophorates, taxa traditionally allied with deuterostomes, occupy basal positions within their respective protostomian clades, deuterstomy most likely represents a suite of characters plesiomorphic for bilaterians.

Defining phyla: evolutionary pathways to metazoan body plans

It is concluded that a benthic radiation of animals could have supplied the ancestral lineages of all but a few phyla, is consistent with molecular evidence, accords well with fossil evidence, and accounts for some of the difficulties in phylogenetic analyses of phyla based on morphological criteria.

Class-level relationships in the phylum Cnidaria: evidence from mitochondrial genome structure.

The structure of the mitochondrial genome in representatives of the four extant cnidarian classes and in the phylum Ctenophora is surveyed, finding that all anthozoan species tested possess mtDNA in the form of circular molecules, whereas all scyphozoan, cubozoa, and hydrozoan species tested display mt DNA in the forms of linear molecules.

Life Cycle of Tripedalia cystophora Conant (Cubomedusae)

The opinion, held by many zoologists, that the Cubomedusae are an aberrant order of the Class Scyphozoa has therefore derived from a knowledge of the medusa generation alone, and the view of some authors that the polyp is the stem form of all recent Cnidaria, have led to efforts to elucidate the life cycle of a member of this order.

Recent Advances in Our Knowledge of the Myxozoa

It is indicated that the Myxozoa are closely related to Cnidaria, and marine taxa at the genus level branch separately from genera that usually infect freshwater fishes; taxa cluster more by development and tissue location than by spore morphology.
...