Megabat evolved early in the lineage of chiropterans. Although echolocation was later lost in family Pteropodidae, bats in the genus "Rousettus" are capable of primitive echolocation through clicking their tongues, and some species have been shown to create clicks similar to those of echolocating bats using their wings. Both echolocation and flight are energetically expensive processes. The nature of the flight and echolocation mechanism of bats allows for creation of echolocation pulses with minimal energy use. Energetic coupling of these two processes is thought to have allowed for both energetically expensive processes to evolve in bats. The loss of echolocation may
Type family versa. Type families are regarded as being generally easier to type-check than functional dependencies. Another advantage of associated types over functional dependencies is that the latter requires clients using the type class to state all of the dependent types in their contexts, including ones they do not use; since associated types do not require this, adding another associated type to the class requires updating only the class's instances, while clients can remain unchanged. The main advantages of functional dependencies over type families are in their added flexibility in handling a few unusual cases. Type family In computer science, a type