Iron Helped to Forge Life’s Early Building Blocks

(Inside Science) -- Faced with Flintstones vitamins, many of us learn during childhood that iron is an essential nutrient for our diets, by carrying oxygen in blood and performing so many other important functions in our bodies. Now, scientists hypothesize that iron may have played an even more essential role during our planet’s childhood, for the benefit of all life on our planet.

Three billion years ago, the Earth’s atmosphere was poor in oxygen, but had plenty of iron. Iron and oxygen have an intimate relationship even outside of our bodies. The two elements are highly reactive with each other chemically.The later presence of oxygen in the air would create chemical “oxidation” reactions that would form rust deposits in the Earth.

But according to researchers at the NASA Astrobiology Institute at the Georgia Institute of Technology, iron once helped ribonucleic acid (RNA) molecules perform biochemical tasks now predominantly assumed by DNA and proteins. In the researchers’ computer simulations and experiments, published yesterday in the journal PLoS One , iron helped RNA molecules maintain their shape and carry out their functions, playing the role that’s currently performed by magnesium, which is now more available for biochemical reactions. In this way, RNA may have fact helped shoulder the task of helping living forms to develop. The researchers are now investigating the possibility that iron may have done an even better job than magnesium in supporting RNA. The importance of iron may go even beyond constituting many of our civilizations’ strongest structures and helping us to use oxygen--it may have helped to usher in life itself.