As my game shop is quiet now...enable to post 
Iron-sulfur world theory
http://en.wikipedia.org/wiki/Iron-sulfur_world_theory
The iron-sulfur world theory is a
hypothesis for the origin of life advanced by Günter
Wächtershäuser, a Munich chemist and patent lawyer, involving forms
of iron and sulfur [1] . Wächtershäuser proposes that an
early form of metabolism predated genetics. Metabolism here means a
cycle of chemical reactions that produce energy in a form that can
be harnessed by other processes. The idea is that once a primitive
metabolic cycle was established, it began
to produce ever more complex compounds. A key idea of the
theory is that this early chemistry of life occurred not in bulk
solution in the oceans, but on mineral surfaces (e.g. iron pyrites)
near deep hydrothermal vents. This was an anaerobic,
high-temperature (near 100°C), high-pressure environment.
The first 'cells' would have been lipid
bubbles on the mineral surfaces. Wächtershäuser has hypothesized a
special role for acetic acid, a simple combination of carbon,
hydrogen, and oxygen found in vinegar. Acetic acid is part of the
citric acid cycle that is fundamental to metabolism in
cells.
Proto-Ecological Systems
William Martin and Michael Russell reported a modified
iron-sulfur-hypothesis in 2002.[4] According to their scenario, the first cellular life
forms may have evolved inside so-called black smokers at seafloor
spreading zones in the deep sea. These structures consist of
microscale caverns that are coated by thin membraneous metal
sulfide walls. Therefore, these structures would solve several
critical points of the "pure" Wächtershäuser systems at
once:
the micro-caverns provide a means of concentrating newly
synthesised molecules, thereby increasing the chance of forming
oligomers;
the steep temperature gradients inside a black smoker allow for
establishing "optimum zones" of partial reactions in different
regions of the black smoker (e.g. monomer synthesis in the hotter,
oligomerisation in the colder parts);
the flow of hydrothermal water through the structure provides a
constant source of building blocks and energy (freshly precipitated
metal sulfides);
the model allows for a succession of different steps of cellular
evolution (prebiotic chemistry, monomer and oligomer synthesis,
peptide and protein synthesis, RNA world, ribonucleoprotein
assembly and DNA world) in a single structure, facilitating
exchange between all developmental stages;
synthesis of lipids as a means of "closing" the cells against the
environment is not necessary, until basically all cellular
functions are developed.
Some of the fundamental ideas of the
iron-sulfur theory can be summarized in the following brief recipe
for life: Boil water. Stir in iron sulfide and nickel sulfide.
Bubble in carbon monoxide and hydrogen sulfide gas. Wait for
peptides to form.
More technically, Wächtershäuser hypothesized the following steps
for producing proteins:
Produce acetic acid through metallic ion catalysis.
Add carbon to the acetic acid molecule to produce three-carbon
pyruvic acid.
Add ammonia to form amino acids.
Produce peptides and then proteins.
Both acetic acid and pyruvic acid are key chemicals in the citric
acid cycle.
In 1997, Wächtershäuser and Claudia Huber
mixed carbon monoxide, hydrogen sulfide, nickel sulfide, and iron
sulfide particles at 100°C and demonstrated that amino acids could
form.[2] The following year, using the same ingredients, they were
able to produce peptides.[3]
http://www.pbs.org/wgbh/evolution/library/faq/cat02.html
5 to 8 million years ago. Shortly
thereafter, the species diverged into two separate lineages. One of
these lineages ultimately evolved into gorillas and chimps, and the
other evolved into early human ancestors called
hominids.
3. Does evolution stop once a species has become a
species?
Evolution does not stop once a species becomes a species. Every
population of living organisms is undergoing some sort of
evolution, though the degree and speed of the process varies
greatly from one group to another. Populations that experience a
major change in environmental conditions, whether that change comes
in the form of a new predator or a new island to disperse to,
evolve much more quickly than do populations in a more stable set
of conditions. This is because evolution is driven by
natural selection, and because when the environment changes,
selective pressures change, favoring one portion of the population
more heavily than it was favored before the change.
