A family-level analysis of this record shows that past insect diversity is governed by low origination and extinction rates, both decreasing toward the Recent. This feature, in addition to prolonged taxal durations, has conferred on insects significant immunity from extinction. Nevertheless, the most profound event in insect history, the end-Permian extinction, decimated the Paleozoic Insect Fauna but allowed survival of lineages that gave rise to the Modern Insect Fauna of the Mesozoic and Cenozoic. A plot of durations of these categories discloses a distinct trend of ecomorphologic disparity peaking considerably earlier than taxonomic diversity, indicating that taxonomic diversification eventually partitioned earlier-created, major ecological roles. Entry into each of these categories has occurred iteratively and convergently between and within the Paleozoic and Modern Insect Faunas.
Insect history is divided into five phases.
These data indicate that insect success is attributable to intricate, multiplicative, and probably extinction-buffered associations with other organisms, especially vascular plants.