Contributions to Zoology

Contributions to Zoology, 71 (1/3) (2002)

Divergence and convergence in early embryonic stages of metazoans

Frietson Galis , Barry Sinervo

Institute of Evolutionary and Ecological Sciences, Leiden University P.O. Box 9516, 2300 RA Leiden, Netherlandsgalis@rulsfb.leidenuniv.nl

Biology Department, University of California Santa Cruzsinervo@biology.ucsc.edu

Keywords: evolutionary conservation, pleiotropy, cleavage, gastrulation, organogenesis, multicellularity, phylotypic stage

Similarity due to conservation or homoplasy

Conservation, convergence and divergence in patterns of cleavage

Mechanistic causes of cleavage patterns

Understanding of diversity and similarity

Conservation, convergence and divergence in patterns of gastrulation

Conservation, convergence and divergence in early organogenesis

What causes conservation of early stages of organogenesis relative to the divergence seen at other stages?

Modularity and the divergence of form in late organogenesis

The relationship between divergence of early and late ontogenetic stages

Acknowledgements