Origins of signalling and memory: Matters of life versus death

This review focuses on the principles in cell-cell communication and cellul ar ability to respond to external chemical changes which have been so cruci al for the development of life on planet Earth. We now know that the capaci ty of free-living organisms which evolved more than a billion years ago to respond to intercellular signal molecules, originating either from themselv es or from other sources in their vicinity, is so similar - possibly even m ore sophisticated - to that of the cells in our own body, and these finding s have had a major impact on our struggle to understand how life has evolve d and how it can be maintained. Attention is drawn to the very important to pic of mechanisms in cell death, bring seen as an aggressive and very power ful instrument in the continuance of life and ability of life to proliferat e into a plethora of new species, and use insulin-related material as our p aradigm. Such signal molecules (hormones) may have played a major role in c ellular maintenance throughout evolution.