Research project: Phylogeny of the Isopoda among the Peracarida

Dates

Start date:
2008

Museum investigators

Funded by

  • Travel Support: German Research Foundation (DFG)

Description

The phylogeny and classification of the Isopoda presented in the paper Brusca & Wilson (1992) was preliminary because it used only higher level taxa, thus limiting the detail that could be represented. Recent separate molecular and morphological studies by other authors have found results that conflict with this original effort and also with each other.

Even at this late date, the relationships of isopod suborders and of the isopods to other related crustaceans are still controversial. At the invitation of Professor Stefan Richter (University of Rostock, Germany), I presented a study of isopod relationships as determined by direct optimisation analysis of morphological and molecular data. This study attempts to find a stable position for the Isopoda within the larger group Peracarida. An additional goal of this research is to assess the in-group relationships of the Isopoda. A practical goal is to employ useful techniques that are not in broad use in the molecular phylogenetics community.

This study is innovative because a large amount of data gleaned from the literature and GenBank are used. At the moment, the working database has 75 carefully chosen taxa. The molecular component uses small subunit ribosomal DNA data available on GenBank with additional sequences that have not been published. Unlike all previous studies, this project will combine all data, molecular and morphological, into a single analysis. The analysis uses a method called Direct Optimisation in the phylogenetic analysis. This method is desirable because standard fixed multiple alignments create imaginary "gaps" in the dataset that are applied to all taxa, even though insertion-deletion events in the gene are confined to specific clades, as they are in the direct optimisation method.

In June 2008, the progress report was presented as a Keynote Speaker address at the International Crustacean Society Conference in Galveston, Texas, and a more complete version was presented in Rostok during October 2008.


Dr George D. F. (Buz) Wilson , Principal Research Scientist
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