ABSTRACT
An advantage of focusing on protein networks, and thus taking a systems biology perspective, is that it provides a helpful context in which to discuss evo-devo comparisons
across the phyla. ere are three other reasons for taking this approach. First, it is parsimonious – there are relatively few networks compared with the vast number of proteins, and many are homologous; second, it naturally links genomic and phenotypic activity. ird, and of particular importance, it provides a natural framework for analyzing the functional way in which anatomical dierences between related organisms, that is those that share a last common ancestor, might have arisen through variation. is is because networks occupy a mid-way step in the mechanisms by which the genotype aects the phenotype.
