Figure 1.

Schematic phylogenetic tree representing the insect Orders comprising species where genome sequencing projects have been completed or are in an advanced stage. The figure is a greatly simplified version of a phylogeny shown in [9] representing the largely agreed relationships between these Orders, plus the major evolutionary transitions for insects (as deduced by synamorphic characters, that is, novel characters derived from preexisting ones) along a time scale expressed in millions of years from present. For each Order with species involved in a genome sequencing project, the node corresponding to its separation from its most closely related order (extant or extinct) is shown (dashed lines represent sister clades).