Is evolution backtracking? Physorg reports:
The extravagant headgear of small bugs called treehoppers are in fact wing-like appendages that grew back 200 million years after evolution had supposedly cast them aside, according to a study published Thursday in Nature.
That’s probably shocking news if you are an entomologist, and challenges some very basic ideas about what makes an insect an insect, the researchers said. The thorax of all insects is by definition divided into three segments, each with a pair of legs.
In most orders, there are also two pairs of wings, one on the middle segment of the thorax and another at the rear. Other orders such as flies and mosquitoes have only one set of wings, at the rear, and a few — most ants, for example — have no wings at all.