Certain flightless beetles have wings that have no function. The wings are an example of which type of structure?
The wings on the beetles are examples of vestigiality. Vestigiality is a structure with attributes that have apparently loss its ancestral function but stil present during evolution. It is a normal evolutionary process in the changing environment that does not pressure them to evolve.
These wings are a type of vestigial structures, that is they are a remainder of the time when the beetles could actually fly, but stopped doing so over time due to the lack of stimulus for flight.