Skip to content. | Skip to navigation

Personal tools

You are here: Home / Library / RBINS Staff Publications / Metazoan relationships on the basis of 18S rRNA sequences: A few years later

B.M.H.a Winnepenninckx, Y.D.E.a Van Peer and T.a Backeljau (1998)

Metazoan relationships on the basis of 18S rRNA sequences: A few years later

American Zoologist, 38(6):888-906.

The 18S rRNA database is continuously growing and new tree construction methods are being developed. The present study aims at assessing what effect the addition of recently determined animal 18S rRNA sequences and the use of a recently developed distance matrix calculation method have on the results of some previously published case studies on metazoan phytogeny. When re-assessing three case studies, part of their conclusions was confirmed on the basis of the present 18S rRNA data set: 1) the monophyly of Arthropoda; 2) the monophyly of the Vestimentifera-Pogonophora and their protostome character, 3) the doubt about the monophyletic origin of Echiura-Sipuncula and 4) the coelomate character of Nemertea. Yet, it is also demonstrated that some of the previous results are no longer warranted when updating the analyses: 1) the monophyly of both the Annelida and the Eutrochozoa; 2) the sister-group relationship of Echiura to Vestimentifera-Pogonophora and 3) the polyphyly of the Mesozoa and their close relationship to Myxozoa and Nematodes. In addition, some new very preliminary evidence is provided for: 1) a common ancestry of Platyhelminthes and Mesozoa and the monophyly of the latter group and 2) the monophyly of Clitellata, Hirudinida and Oligochaeta. Finally, doubt is casted on the monophyly of the Polychaeta and the poiychaete orders Spionida, Phyllodocida, and Sabellidae. Of course, these hypotheses also need further testing.

cited By (since 1996)52

Document Actions

Menu

 
RBINS Staff
add or import reference(s)
  • add a PDF paper
    (Please follow editors copyrights policies)
  • add a PDF poster