Talking about Iron Pyrite in yesterday’s post got me interested in its origins. I came across this interesting article in Astrobiology Magazine that said that some forms of iron pyrite may have acted as a template that led to reactions that led to the formation of amino acids, proteins and other ingredients of life.
When pyrite absorbs sunlight, a weak electrical current is generated which would have been enhanced in the early Earth’s anaerobic environment. Matthew Edwards of the University of Calgary said that this photoelectric quality could have led to carbon and nitrogen fixation which could have led to a primitive metabolism at these fixation sites.
It is suggested that a biofilm could have formed on the surface of the iron pyrite. The surface of iron pyrite would have protected the organic molecules from not only wave action, but also against the harmful effects of ultraviolet light. If the organic molecules were to form further than ten nanometers from the surface of the iron pyrite, then the molecules would tear themselves apart when excited by the UV, but if they were within ten nanometers of the surface then the iron pyrite would absorb the energy and then release it as heat (Tributsch).
Tributsch also suggested that chlorophyll may have originated within this ten nanometer area on the surface of pyrite and may have supplied energy to primitive cells. The first life forms appeared at least 3.8 billion years ago, and it appears that photosynthesis may have appeared by 3.7 billion years ago.