Fig. 8. Proposed core cell lineage of sensory organs in Drosophila and creation of diversity. Sensory diversity is generated when different processes are added to this basic pattern of cell division. Two processes may be distinguished: first, processes in which cell identity is changed without altering the configuration of the core pattern of cell divisions (red arrows); and, second, processes in which new complexity is added to this core without profound modifications in cell identity (blue arrows).