Zebra finches, which normally learn their complex courtship songs from their fathers, spontaneously developed the same songs all on their own after only a few generations.

• 斑胸草雀通常是从父辈那里学习到复杂的求爱歌曲，不过即使不从父辈那儿学习，几代之后，它们也可以自发地学会所有这些歌曲。