Many of us would love the superpower to fly, and for good reason: Flight offers a crucial evolutionary advantage. Flying enables an animal to travel large distances quickly, in search of food and new habitats, while expending far less energy than walking. Through flight, insects colonized the planet and fostered the massive diversification of flowering plants by acting as efficient pollinators. They also enabled the evolution of other creatures like reptiles, birds, and mammals by serving as ample food supply.
Flight has evolved four times in the history of life on Earth: in birds, bats, pterosaurs, and insects. The first three groups of animals evolved their wings from arms, making these wings straightforward to understand as other similar animals have analogous bones and musculature. Insect wings, however, have no muscles or nerves. They are instead controlled by muscles located inside the body that operate a system of marionette-like pulleys within a complex hinge at the base of the wing.
“The fly wing hinge is perhaps the most mysterious and underappreciated structure in the history of life,” says Michael Dickinson, Caltech’s Esther M. and Abe M. Zarem Professor of Bioengineering and Aeronautics, executive officer for biology and biological engineering and an an affiliated faculty member with the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech.. “If insects had not evolved this very improbable joint to flap their wings, the world would be a very different place, absent of flowering plants and familiar creatures like birds, bats—and probably humans.”
Just how an insect controls this tiny, intricate structure in the fruit fly Drosophila melanogaster is the subject of a new study by Dickinson and his colleagues. Using high-speed cameras and machine learning, Dickinson’s lab collected data on tens of thousands of fly wingbeats and created a map of how fly muscles puppeteer the motion of the wing hinge to create agile aerodynamic flight maneuvers.
The study is described in a paper, titled “Machine learning reveals the control mechanics of an insect wing hinge” appears in the journal Nature on April 17.