Sökning: L773:1540 7063 OR L773:1557 7023
> (2002-2004) >
Unsegmented annelid...
Unsegmented annelids? Possible origins of four lophotrochozoan worm taxa
-
Halanych, K. M. (författare)
-
- Dahlgren, Thomas G., 1963 (författare)
- Gothenburg University,Göteborgs universitet,Zoologiska institutionen,Department of Zoology
-
McHugh, D. (författare)
-
(creator_code:org_t)
- 2002
- 2002
- Engelska.
-
Ingår i: Integrative and Comparative Biology. - 1540-7063. ; 42:3, s. 678-684
- Relaterad länk:
-
https://gup.ub.gu.se...
Abstract
Ämnesord
Stäng
- In traditional classification schemes, the Annelida consists of the Polychaeta and the Clitellata (the latter including the Oligochaeta and Hirudinida). However, recent analyses suggest that annelids are much more diverse than traditionally believed, and that polychaetes are paraphyletic. Specifically, some lesser-known taxa. (previously regarded as separate phyla) appear to fall within the annelid radiation. Abundant molecular, developmental, and morphological data show that the Siboglinidae, which includes the formerly recognized Pogonophora and Vestimentifera, are derived annelids; recent data from the Elongation Factor-1alpha (EF-1alpha) gene also suggest that echiurids are of annelid ancestry. Further, the phylogenetic origins of two other lesser-known groups of marine worms, the Myzostomida and Sipuncula, have recently been called into question. Whereas some authors advocate annelid affinities, others argue that these taxa do not fall within the annelid radiation. With advances in our understanding of annelid phylogeny, our perceptions of body plan evolution within the Metazoa are changing. The evolution of segmentation probably is more plastic than traditionally believed. However, as our understanding of organismal evolution is being revised, we are also forced to reconsider the specific characters being examined. Should segmentation be considered a developmental process or an ontological endpoint?
Ämnesord
- NATURVETENSKAP -- Biologi (hsv//swe)
- NATURAL SCIENCES -- Biological Sciences (hsv//eng)
Nyckelord
- annelida
- systematics
- segmentation
Publikations- och innehållstyp
- ref (ämneskategori)
- art (ämneskategori)
Hitta via bibliotek
Till lärosätets databas