Male humpback whales (Megaptera novaeangliae) sing a long, stereotyped, vocally learnt and culturally transmitted song display. At any point in time most males within a population will sing the same version (arrangement and content) of this complex sexual display. However, the song is continually evolving and males must constantly learn and incorporate these changes into their own song to maintain cultural conformity. In addition to evolutionary change, song also undergoes striking “revolutions” where a novel song introduced from a neighboring population rapidly and completely replaces the existing song. Multiple humpback whale song revolutions have spread across the South Pacific region from the east coast of Australia across to French Polynesia, and on to Ecuador, with a one-to-two-year delay. This has occurred regularly, rapidly, and repeatedly across the region; the level and rate of change is unparalleled in the animal kingdom. However, we still have a limited understanding of the underlying mechanisms driving this cultural phenomenon and how these interact with sexual selection. Using empirical data, I will present our current understanding of the mechanisms involved in the song learning process, female choice of song features, and finally the evolutionary implications for this cultural phenomenon.
Ellen C. Garland (Wed,) studied this question.