For those of you out there overwhelmed by the extensive and intricate network of protein interactions in even the most basic explanations of cell biology, Science’s STKE has a great review out: Rules for Modeling Signal-Transduction Systems.
Sure, it’s a tough thing to wrap your head around, but cell biology is reducible in its complexity.
And another interesting perspective on evolution: Topological Patterns in Metazoan Evolution and Development, in Bulletin of Mathematical Biology. Isaeva et al. argue that metazoan morphogenesis, from sponges to chordates, may be represented as topological modification(s) of the epithelial surfaces of an animal body.