Paleoentomology

Paleoentomology

Phylogeny, or phylogenetics, is the study of evolutionary relationships among groups of organisms, which is discovered through evidence such as molecular sequencing and morphology. Insects are a highly diverse, worldwide group, and therefore have a complex evolutionary history. They have conquered every terrestrial environment and have many intricate interactions with a wide variety of organisms, including predator-prey relationships. The taxonomy of insects is also included here, which is the classification, identification, and naming of species, as taxonomy is richly informed by phylogenetics, but remains methodologically and logically distinct.

The evolution of insects dates back to the Devonian period, with the oldest definitive insect fossil being the Rhyniognatha hirsti, estimated at 407 to 396 million years ago. Global climate conditions changed several times during the history of the earth, along with it the diversity of insects. The Pterygotes underwent a major radiation in the Carboniferous while the Endopterygota species underwent another major radiation in the Permian. Survivors of the mass extinction at the PT boundary evolved in the Triassic to what are essentially the modern Insecta Orders that persist to modern times. Most modern insect families appeared in the Jurassic, and further diversity probably in genera occurred in the Cretaceous. It is believed that by the Tertiary, there existed many of what are still modern genera; hence, most insects in amber are, indeed, members of extant genera. What seems most fascinating is that insects diversified in a relatively brief 100 million years (give or take) into the modern forms that exist with minor change in modern times.