Evolutionary biologists have long considered bird song to be an exclusively male trait, resulting from sexual selection. A new paper says that's not the whole story.
The results of their analysis, now published in Nature Communications
, showed that the common ancestor of modern songbirds had female song.
It doesn't turn Darwin's theory of sexual selection on its head, but it does mean there is more to the story than what Darwin proposed. Sexual selection has played a major role in the evolution of elaborate bird song but other selection pressures or processes have also probably played a role, especially at the initial stages of its evolution, the authors note.