I don't know much
about chemistry but from what I do know (very little) wouldn't a chemical
intervention/event cause a sudden change in the evolution of an organism and
wouldn't this argue against the gradual adaptionism of natural selection? just
curious
Ruby I am not sure
what you are asking but hopefully this will answer your question.......
For abiogenesis to occur simple molecules needed to bind in a specific order to
create more complex molecules (nucleotides) that eventually resulted in a very
complex molecule that had the ability to replicate itself (RNA and subsequently DNA). At this point
natural selection started to influence the process favouring variations that
made replication more efficient.
In the lab complex
biochemical synthesis, such as the manufacture of peptides, uses a technique
called solid phase synthesis whereby the amino acids making up the peptides are
built up on tiny porous beads in a controlled way. There are different
hypothesises as to how nucleotides were built in nature but it would seem that
a vehicle, acting as the equivalent of solid phase bead, was utilised to allow
the step by step combination. For example, the vehicle may have been Iron disulphide
found in hydrothermal vents or it may have been a clay such as montmorillonite,
the actual conditions are of course one of the big unknowns of abiogenesis. The bottom line is, once these initial
reactions occurred, in the order required, nucleotides were created which then
combined to form self-replicating molecules. These molecules used their own molecular structure to provide the vehicle which ensured successful replication.
To answer your
question directly as I understand it................
Evolution at the chemical level occurs due to
changes in the arrangement of the base pairs in the self-replicating molecules.
Some chemicals are mutagenic and these can result in such changes, most of
which are neutral to the viability of the phenotype. Some of these mutations
may be detrimental to the phenotype and will result in cell death or
uncontrolled division of mutated cells (cancer). It is also possible that such
a mutation could potentially be beneficial and theoretically if a beneficial mutation occurs
in gamete (sex cell) it could be inherited and subsequently be important in
evolutionary terms. Mutations that do not occur in the gametes have no
influence on evolution.