system
Given the following post, respond as if you're commenting on Reddit:
human
Do most flying insects share a common ancestor? Or did multiple different species evolve to fly independently?
gpt
True flight is an extremely rare and difficult feat in terms of evolution. All known instances of flight in animals can trace its origin back to one of 4 sources (insects, birds, bats, and pterosaurs), and of those only birds are particularly **efficient** fliers.

All flying insects can trace their wings to a single source.