SELF-DESTRUCTION KEY TO EVOLUTION. “”The observation that plant cells share with animal cells the capacity to self-destruct in response to environmental changes and cell signaling has reinforced the idea that programmed cell death may have played an essential role in the development, survival and evolution of most, if not all, multicellular organisms.”
http://www.nature.com/cdd/journal/v9/n4/full/4400950a.html