Phylogenetic considerations of clonality, coloniality, and mode of germline development in animals
Version of Record online: 28 MAY 2003
© 2003 Wiley-Liss, Inc.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Volume 297B, Issue 1, pages 35–47, 15 June 2003
How to Cite
Blackstone, N. W. and Jasker, B. D. (2003), Phylogenetic considerations of clonality, coloniality, and mode of germline development in animals. J. Exp. Zool., 297B: 35–47. doi: 10.1002/jez.b.16
- Issue online: 28 MAY 2003
- Version of Record online: 28 MAY 2003
- Manuscript Accepted: 24 MAR 2003
- Manuscript Received: 17 DEC 2002
- National Science Foundation. Grant Number: IBN-00-90580
The hypothesis that individuality is a derived trait in animals (Buss, '87, The Evolution of Individuality, Princeton, NJ: Princeton University Press; Michod, '99, Darwinian Dynamics, Princeton, NJ: Princeton University Press) can be further tested by a “tree-based” analysis utilizing a comparative methodology and recent phylogenies. We conducted a maximum parsimony analysis in which we mapped character states for clonality, coloniality, and mode of germline development onto four recent phylogenetic hypotheses (Peterson and Eernisse, 2001, Evol Dev 3:170–205). Clonality appears to be a shared primitive character for metazoans. Coloniality, on the other hand, is a derived trait found in relatively few phyla. The germline appears to have been derived at or near the origin of the first bilaterians. The stem-lineage metazoan thus appears to have been a clonal, acolonial organism that exhibited somatic embryogenesis. The stem-lineage bilaterian also was likely clonal and acolonial. Nevertheless, this lineage likely exhibited preformation, i.e., its germline was determined during embryonic development. In addition to supporting the hypothesis that the germline is a derived feature in animals, this analysis is relevant to current debates concerning the nature of the latest common ancestor of the bilaterians. J. Exp. Zool. (Mol. Dev. Evol.) 297B: 35–47, 2003. © 2003 Wiley-Liss, Inc.