A bug that is not an insect
The family tree of life has a newly discovered branch. Genetic studies comparing mitochondrial DNA have been thought to be the group from which insects arose, the Collembola -- wingless hexapods (six legs) commonly called springtails -- turns out not to be closely related to insects after all.
Instead, these creatures belong to a separate evolutionary lineage that predates even the separation of insects and crustaceans.
"Based on the similarities in their body organization, their six legs, and other morphological characteristics, it has been generally accepted that the collembolans were the basal stock from which insects are," says Jeffery Boore, a biologist with Lawrence Berkeley National Laboratory. The study (reported in Science) indicated that they evolved separately from insects and independently adapted to life on land. Collaborating with Boore on the project were Francesco Nardi, Giacomo Spinsanti, Antonio Carapelli, Romano Dallai and Fransesco Frati,all with the Department of Evolutionary Biology at the University of Siena in Italy.