For organs to form during embryonic development, some cells must commit suicide. Without such programmed cell death, we would all be born with webbed feet, like ducks.

• 对胚胎发育期间形成的器官来说，部分细胞必须自绝生路。如果没有这种程序化细胞死亡，我们生下来都会像鸭子一样有带蹼的脚。