DEATH AS A SIDE-EFFECT? “We must ask of unicellular organisms the same question we asked about multicellular organisms: Is death the function of POD, or merely a side effect? Multicellular organisms undergoing POD typically do leave offspring, so active death that is a byproduct of mechanisms “designed” to regulate investment in reproduction is a viable (and often supported) hypothesis for multicellular POD.” (POD = programmed organismal death).
http://www.esciencecentral.org/journals/are-internal-death-promoting-mechanisms-ever-adaptive-2329-9002.1000113.pdf