Why might we think that biology needs to employ a richer concept? One thought is that genes play a special, instructional role in development, telling the embryo how to grow. It is true that genes carry Shannon-information about phenotypes: the genome of a fertilized egg predicts much of the resulting phenotype. In mammals, for example, chromosome structure predicts the sex of the adult animal. But if an informational relationship between gene and phenotype is supposed to involve a distinctive instruction-like mode of causation, then this cannot be information in Shannon’s sense.  For environmental factors, not just genes, “carry information” about phenotypes, in Shannon’s sense. With respect to Shannon information, there is a “parity” between the roles of environmental and genetic causes (Griffiths and Gray 1994). Moreover, if we are using Shannon’s concept, then the informational relationship between genotype and phenotype is symmetrical. For example, once a reader knows that both authors of this article are male, they can predict that we both carry a Y-chromosome.  Some talk about information in biology is consistent with these features of Shannon information, but some is not. In particular, it is usually thought that at least some applications of informational language to genes ascribe to them a property that is not ascribed to environmental conditions, even when the environment is predictively important.