Hello folks,
Damhnait McHugh's <dmchugh at oeb.harvard.edu> interesting paper on the above
subject is readable online at:
http://www.pnas.org/all.shtml (Do a search on vol 94 and p8006)
Or a version for printing at:
http://www.pnas.org/cgi/reprint/94/15/8006
This link is to a page offering the link to DOWNLOAD the Reprint (PDF)
version of: PNAS McHugh 22 July 1997; 94 (15):8006-8009. (191K). And
there is some info about printing PDF files. You need Adobe Acrobat reader
(free from Adobe) to read & print this format, but it gives a very nice
copy for filing.
McHugh, D. 1997. Molecular evidence that echiurans and pogonophorans are
derived annelids. Proceedings of the National Academy of Sciences USA 94:
8006-8009
ABSTRACT "The Annelida, which includes the polychaetes and the
clitellates, has long held the taxonomic rank of phylum. The unsegmented,
mud-dwelling echiuran spoon worms and the gutless, deep-sea pogonophoran
tube worms (including vestimentiferans) share several embryological and
morphological features with annelids, but each group has also been
considered as a separate metazoan phylum based on the unique characters
they display. Phylogenetic analyses of DNA sequences from the nuclear gene
elongation factor-1a place echiurans and pogonophorans within the Annelida.
This result, indicating the derived loss of segmentation in echiurans, has
profound implications for our understanding of the evolution of metazoan
body plans, and challenges the traditional view of the phylum-level
diversity and evolutionary relationships of protostome worms."
List members may find the 2nd to last paragraph of the paper particularly
challenging.
:-)
--
Geoff Read <g.read at niwa.cri.nz>
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