The unique model of this story appeared in Quanta Magazine.

On heat summer season nights, inexperienced lacewings flutter round brilliant lanterns in backyards and at campsites. The bugs, with their veil-like wings, are simply distracted from their pure preoccupation with sipping on flower nectar, avoiding predatory bats, and reproducing. Small clutches of the eggs they lay hold from lengthy stalks on the underside of leaves and sway like fairy lights within the wind.

The dangling ensembles of eggs are lovely but additionally sensible: They maintain the hatching larvae from instantly consuming their unhatched siblings. With sickle-like jaws that pierce their prey and suck them dry, lacewing larvae are “vicious,” mentioned James Truman, a professor emeritus of improvement, cell and molecular biology on the University of Washington. “It’s like ‘Beauty and the Beast’ in one animal.”

This Jekyll-and-Hyde dichotomy is made doable by metamorphosis, the phenomenon finest recognized for reworking caterpillars into butterflies. In its most excessive model, full metamorphosis, the juvenile and grownup types look and act like completely completely different species. Metamorphosis will not be an exception within the animal kingdom; it’s nearly a rule. More than 80 percent of the recognized animal species right this moment, primarily bugs, amphibians and marine invertebrates, bear some type of metamorphosis or have complicated, multistage life cycles.

The technique of metamorphosis presents many mysteries, however a number of the most deeply puzzling ones middle on the nervous system. At the middle of this phenomenon is the mind, which should code for not one however a number of completely different identities. After all, the lifetime of a flying, mate-seeking insect may be very completely different from the lifetime of a hungry caterpillar. For the previous half-century, researchers have probed the query of how a community of neurons that encodes one id—that of a hungry caterpillar or a murderous lacewing larva—shifts to encode an grownup id that encompasses a totally completely different set of behaviors and wishes.

Truman and his group have now realized how a lot metamorphosis reshuffles components of the mind. In a recent study printed within the journal eLife, they traced dozens of neurons within the brains of fruit flies going by metamorphosis. They discovered that, not like the tormented protagonist of Franz Kafka’s quick story “The Metamorphosis,” who awakes in the future as a monstrous insect, grownup bugs seemingly can’t keep in mind a lot of their larval life. Although lots of the larval neurons within the examine endured, the a part of the insect mind that Truman’s group examined was dramatically rewired. That overhaul of neural connections mirrored a equally dramatic shift within the conduct of the bugs as they modified from crawling, hungry larvae to flying, mate-seeking adults.

Their findings are “the most detailed example to date” of what occurs to the mind of an insect present process metamorphosis, mentioned Deniz Erezyilmaz, a postdoctoral analysis scientist on the University of Oxford’s Center for Neural Circuits and Behavior who used to work in Truman’s lab however wasn’t concerned on this work. The outcomes might apply to many different species on Earth, she added.