Life depends as much on the flow of information as on the flow of energy. I will start by reviewing attempts to make this intuition precise using information theory in the context of sensory neuroscience and connect that to our recent work on modelling  the responses of large populations of retinal neurons. I will show how analogous approaches can be used to understand genetic regulatory networks, in particular, the gap gene system active during early development in the fruit fly embryo. Lastly, I will outline our recent efforts to build a theory for genetic regulatory networks, where regulatory network structure and parameters can be predicted from first principles rather than fit to data.