Between the Rocks and the Stars dives deep into the relationships that shape the natural world. The book presents a collection of vignettes from the wild, each of which describes the natural advantage of a particular organism. These true-to-life accounts are then posed in particular circumstances that illustrate the principles—commensalism, speciation—that shape the place of these organisms in their living environment. Some stories cover topics in geology and cosmology, describing the physical world context in which natural history progresses across the eons.
Underlying themes in the book include the network of connections that link all these organisms together and the adaptations they make to the physical world in which they must find themselves a home.