Denis Nobel, one of the pioneers of Systems Biology, puts forward his view of how biology is more than (maybe even other than?) just genes in this extremely readable little book. He does this by explicit use of metaphor and (invented) anecdote in order to make his points, but is also careful to point out where this rhetorical approach breaks down.
The main metaphor is one of an orchestra producing music, where the genes might be the analogue of the musical score; necessary, maybe, but clearly by no means sufficient, to generate the sound of the symphony. There are several additional vital aspects to biology, including the fact that a new organism does not start ab initio, but in the context of a lot of pre-existing chemicals in the egg cell, and that these pre-existing chemicals have a natural behaviour dictated by the rules of physics and chemistry that therefore do not need to be encoded in the genome; the organism gets all this extra information, and more, for free from its environment. This extra environmental information is illustrated is an amusing, and memorable, anecdote of the recipe for an omelette that leaves out a crucial preparation step, because, simply, "how else would you prepare an omelette?" We also get some combinatorics that demonstrate why, when comparing our genomes to those of other species, 95% the same in the chromosome string can become mind-boggling fantastically different in the resulting behavioural network combinations.
This is a great little introduction to the concepts of Systems Biology, how the organism affects the genome as much as the genome affects the organism, and how it simply doesn't make sense to try to explain everything just from the bottom up. This doesn't mean Systems Biology is some woolly, hand-waving, purely holistic approach -- bottom-up reductionist information is still an important component, but only a component. Recommended.