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
Generally recognized as safe and effective Generally recognized as safe and effective Generally recognized as safe and effective (abbreviated as GRASE, GRAS/E, or GRAS/GRAE) is designation for certain old drugs that do not require prior approval from the U.S. Food and Drug Administration in order to enter the United States marketplace because they are generally recognized as safe and effective by medical professionals. The Federal Food, Drug, and Cosmetic Act defines a "new drug", which requires prior approval, as any drug "the composition of which is such that such drug is not generally recognized, among experts qualified by scientific training and experience to evaluate the safety