How did insects get their wings?
After 100 years of debate, that is the mystery just solved by biologists at the Marine Biological Laboratory in Woods Hole.
Until now, many scientists believed that insect wings were ”novel” structures that sprang up with no corresponding structure in the ancestor.
But postdoctoral researcher Heather Bruce and MBL Director Nipam Patel helped debunk that theory using gene-editing technology known as CRISPR. It had been known for years that insects share an ancestor with crustaceans.
Still, that discovery didn’t explain everything.
“You might notice that crustaceans don't fly,” she said. “So it's this question, like, where did wings come from? They seem to just kind of pop out of nowhere.”
The story starts about 300 million years ago, when a crustacean with long, flat, paddle-like legs evolved to live on land.
“When insects moved onto land, they had … to support more of their weight on their legs,” she explained.
The two leg segments closest to the animal's body began fusing into the body wall, giving it more stability.
Over time, an outgrowth or "lobe" on those fused legs began to evolve. Those lobes moved up onto the backs of insects and "those later turned into wings,” Bruce concluded.
The study was published this week in Nature Ecology & Evolution.
“Things like … insect wings don't pop out of nowhere,” she said. “They have a structure in the ancestor that they evolved from and that’s a really fun thing to realize about how evolution works and how evolution tinkers with structures,” she said.
Bruce’s discovery has given scientists a new model to learn more about evolution. She’ll now be able to compare insect and crustacean legs to spider and millipede legs to develop a model of how all arthropod legs correspond to each other.
