Evolutionary musicology concerns the "origins of music, the question of animal song, selection pressures underlying music evolution", and "music evolution and human evolution".[46] It seeks to understand music perception and activity in the context of evolutionary theory. Charles Darwin speculated that music may have held an adaptive advantage and functioned as a protolanguage,[47] a view which has spawned several competing theories of music evolution.[48][49][50] An alternate view sees music as a by-product of linguistic evolution; a type of "auditory cheesecake" that pleases the senses without providing any adaptive function.[51] This view has been directly countered by numerous music researchers.[52][53][54]