The conditions required for a
primoridal soup to exist are special. A typical puddle of water does not qualify. Thaxton
defined the conditions as follows: 1) the atmosphere above the puddle needs to contain no
oxygen. 2) The puddle must be shielded from UV rays 3) it must have a way to continually
evaporate and replenish its chemicals. 4) It must not contain a high concentration of salt
(this rules out sea water) and finally 4) It needs to be near an energy source.8
So now assume that every star has ten planets and that each of these planets has 1,000
primordial soups. Thus, at any given time the universe has 7 x 1026 primorial
soups. As some of these are destroyed, others replace them. Assume that every soup
produces organic polymers (chains of amino acids, RNA bases, +other chemicals) at a rate
of 1,000 Kg a year, and that 0.1% of the polymers produced are long enough to have some
function (for example, 50 RNA bases strung together to form a chain counts, 3 does not,
because 3 RNA bases cannot perform the function of a ribozyme, whereas 50 bases might be a
ribozyme). This leads to the production of 1 Kg of suitable polymers per year per soup. If
the average polymer weight is comparable to 30 amino acids, then each soup will produce 2
x 1023 organic polymers of reasonable size per year.
Each year all of the soups combined will produce 1.4 x 1050
polymers. Over the history of the universe (15 billion years), this equates to 2.1 x 1060
polymers. Clearly, this helps chemical evolution. Each polymer created is a try, so the
techniques used earlier in this chapter can now be applied to chemical evolution. The goal
is to figure out if a self replicating molecule can ever evolve given that the universe is
quite big and has been around for a long time. The other goal is to figure out if an
enzyme like G3PD can evolve.
Also realize that we cannot rely on natural
selection to offset the poor odds until useful information is created. So all of these
calculations depend on chance with no help from selection.
Next: RNA Self Replication
Previous: How Many Stars
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