The substrate for evolutionary divergence does not lie in changes in neuronal cell number or targeting, but rather in sensory perception and synaptic partner choice within invariant, prepatterned neuronal processes.
Unexpected structural diversity of nematode small molecules, as revealed by high-resolution phylogenetic analysis, suggests recurrent biochemical innovation, a pattern that is probably typical across animals.
Evolutionary novelty is promoted by a macroevolutionary pulse of developmental plasticity, but is enhanced by secondary fixation, which permits developmental character release and further morphological exploration.
Quantitative genetic analyses reveal remarkably broad genetic variation underlies the requirement for two critical regulatory inputs into a core embryonic gene regulatory network within one animal species.
Caenorhabditis elegans homologs of carboxylesterases that localize to intestinal organelles orchestrate the assembly of modular signaling molecules from building blocks that integrate diverse metabolic pathways.