<P> Montmorillonite, an abundant clay, is a catalyst for the polymerization of RNA and for the formation of membranes from lipids . A model for the origin of life using clay was forwarded by Alexander Graham Cairns - Smith in 1985 and explored as a plausible mechanism by several scientists . The clay hypothesis postulates that complex organic molecules arose gradually on pre-existing, non-organic replication surfaces of silicate crystals in solution . </P> <P> At the Rensselaer Polytechnic Institute, James P. Ferris' studies have also confirmed that clay minerals of montmorillonite catalyze the formation of RNA in aqueous solution, by joining nucleotides to form longer chains . </P> <P> In 2007, Bart Kahr from the University of Washington and colleagues reported their experiments that tested the idea that crystals can act as a source of transferable information, using crystals of potassium hydrogen phthalate . "Mother" crystals with imperfections were cleaved and used as seeds to grow "daughter" crystals from solution . They then examined the distribution of imperfections in the new crystals and found that the imperfections in the mother crystals were reproduced in the daughters, but the daughter crystals also had many additional imperfections . For gene - like behaviour to be observed, the quantity of inheritance of these imperfections should have exceeded that of the mutations in the successive generations, but it did not . Thus Kahr concluded that the crystals "were not faithful enough to store and transfer information from one generation to the next ." </P> <P> In the 1970s, Thomas Gold proposed the theory that life first developed not on the surface of the Earth, but several kilometres below the surface . It is claimed that discovery of microbial life below the surface of another body in our Solar System would lend significant credence to this theory . Thomas Gold also asserted that a trickle of food from a deep, unreachable, source is needed for survival because life arising in a puddle of organic material is likely to consume all of its food and become extinct . Gold's theory is that the flow of such food is due to out - gassing of primordial methane from the Earth's mantle; more conventional explanations of the food supply of deep microbes (away from sedimentary carbon compounds) is that the organisms subsist on hydrogen released by an interaction between water and (reduced) iron compounds in rocks . </P>

Which of the following conditions apply to earth prior to the beginning of life