Early Evolution

Origins of Life and Evolution of Biospheres

, Volume 41, Issue 5, pp 483-493

First online:

Open Access This content is freely available online to anyone, anywhere at any time.

Links Between Hydrothermal Environments, Pyrophosphate, Na+, and Early Evolution

  • Nils G. HolmAffiliated withDepartment of Geological Sciences, Geochemistry Section, Stockholm University Email author 
  • , Herrick BaltscheffskyAffiliated withDepartment of Biochemistry and Biophysics, Stockholm University


The discovery that photosynthetic bacterial membrane-bound inorganic pyrophosphatase (PPase) catalyzed light-induced phosphorylation of orthophosphate (Pi) to pyrophosphate (PPi) and the capability of PPi to drive energy requiring dark reactions supported PPi as a possible early alternative to ATP. Like the proton-pumping ATPase, the corresponding membrane-bound PPase also is a H+-pump, and like the Na+-pumping ATPase, it can be a Na+-pump, both in archaeal and bacterial membranes. We suggest that PPi and Na+ transport preceded ATP and H+ transport in association with geochemistry of the Earth at the time of the origin and early evolution of life. Life may have started in connection with early plate tectonic processes coupled to alkaline hydrothermal activity. A hydrothermal environment in which Na+ is abundant exists in sediment-starved subduction zones, like the Mariana forearc in the W Pacific Ocean. It is considered to mimic the Archean Earth. The forearc pore fluids have a pH up to 12.6, a Na+-concentration of 0.7 mol/kg seawater. PPi could have been formed during early subduction of oceanic lithosphere by dehydration of protonated orthophosphates. A key to PPi formation in these geological environments is a low local activity of water.


Brucite Early evolution Hydrothermal systems Mariana forearc Membrane-bound inorganic pyrophosphatase Proton pump Pyrophosphate Serpentinization Sodium pump Subduction zones