If genes are seen as “carrying a message” in this sense, the message apparently has a prescriptive or imperative content, as opposed to a descriptive or indicative one. Their “direction of fit” to their effects is such that if the genes and the eventual structure produced (the phenotype) do not match, what we have is a case of unfulfilled instructions rather than inaccurate descriptions.  Alternatively, perhaps it is possible to think that the genes are telling the developing phenotype the environment it can expect. For the gene pool from which those genes have been drawn has been filtered by selection. In arid regions of Australia, genes which contributed to the development of leaves whose shape and surface restricted water loss have become common. Hence perhaps we can see these genes as telling the trees: conditions will be dry (for this line of thought, see Shea 2011, 2013).