Reproductive modes, ontogenies, and the evolution of body form

The evolution and development of complex morphological structures, and of body form, can now be addressed hierarchically, using diverse techniques from multiple theoretical perspectives. Such an ‘integrative’ or ‘holistic’ approach is likely to provide more complete insight into the origin of patterns and processes of evolution than the more traditional reductionist mode. Current work on the implications of reproductive mode on the ontogenies of amphibians and the evolution of their body form is an example of that approach. Genome size, egg and clutch size, and a number of other life history traits are involved with developmental rate and pattern (including loss of larval features, ontogenetic repatterning, and modiŽ ed patterns of organogenesis), and reproductive mode (the presumed ancestral egg-laying vs. direct development and viviparity) is correlated and potentially causal for certain patterns. Such correlations are being explored using a variety of approaches, and examples of this work-in-progress are provided.