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_Beginning of Earth _
By: Shannon
There were volcanoes everywhere, there was lava pouring out from the earth in
large quantities. Ash was flying around my very own head landing in my hair.
It was one of the scariest things I have ever seen in my whole entire life.
Then again I am only 16. Right when I tried to figure out what just happened I
got sucked back into my room, like nothing had ever happened. I grabbed my
journal and wrote down the following. The theory of evolution states that
creatures change overtime to suit their surroundings. This is called
environmental adaptation. The more a creature can adapt to its environment the
greater chance it has of living and show an increase in population called
survival of the fittest. A theory developed by a scientist named Charles
Darwin who had conducted extensive research into the environmental adaptations
of animals. The first human species is believed to have evolved only about 7
million years ago. Data indicated that the blood proteins of humans,
chimpanzees, and gorillas are equally different from each other. Scientists
believed that there were all kinds of minerals and gases likely to have been
present billions of years ago. Before I created my time machine I read about a
experiment last year, the German team combined iron, nickel, HS, CO, and
boiling water, and succeeded in generating parts of amino acid molecules. In
this new experiment, they started with fully formed amino acids, added them to
their boiling slurry of metals, gases, and water, and got peptides. They added
fully formed amino acids this time because astronomers have shown that large
quantities of amino acids can form in space. Many astronomers also think that
comets and meteors ferried amino acids to earth's surface early in its
history, and thus the raw material could well have been present near
hydrothermal vents. [In an unrelated article in the July 31 Science, for
example, astronomers report finding huge clouds of amino acids in the
constellation Orion.] Later I read the find out that biochemicals have evolved
near boiling volcanic vents. If the primordial soup did exist it would have
been very dilute. This means that any dissolved chemical compounds might have
bumped into each other far too seldom to react and bring about the formation
of amino acids and nucleic acids. -- The oldest signs of life previously known
on Earth were found in rocks from Australia and South Africa, about 4.5
billion years old. These rocks contain fossil remnants of bacteria-like
organisms, as well as a distinctive "chemical fingerprint" of two isotopes of
carbon. Carbon-12 accounts for 98.9% of naturally occurring carbon, and
carbon-13 accounts for the remaining 1.1%. (A radioactive isotope, carbon-14,
is found in much smaller amounts). As living organisms grow, chemical
reactions in their cells alter the natural ratio of C-13 to C-12 slightly in
favor of more C-12, so that the C-13 to C-12 ratio becomes detectably
different in living organisms from the "standard" ratio. Thus the presence of
extra "light" carbon is a distinctive "footprint" of life, even in the absence
of fossil organisms Greenland contains rocks even older than the
fossil-containing rocks described above, such as the Itsaq gneiss complex in
southern West Greenland estimated to be 4.85 billion years old. These
metamorphic rocks have been forged through extremes of pressure and
temperature. Within a scant billion years of their formation, they were heated
to 500oC at pressures of 5,000 atmospheres. Previous examinations of such
rocks showed no fossils, and suggested that any organic carbon traces had been
"pressure-cooked" into graphite, with alterations in the C-13 to C-12 ratio
that would have destroyed traces of early life. Since it was almost time for
me to come back to my time I remembered that I had brought a camera as well as
film so I took a couple of pictures and I added one of our earth as we know it
today.
Word Count: 653
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