Реферат: Life On Mars Essay Research Paper I
Название: Life On Mars Essay Research Paper I Раздел: Топики по английскому языку Тип: реферат |
Life On Mars Essay, Research Paper I was at home minding my own business when all of a sudden and my bag got sucked back in time. I don’t know or I can’t explain really what occurred, but I found my self at the beginning of time itself. So I decided to make down my own thoughts and what I saw. Here is my journal entry. Date: No sure when (around 4.5 billion years ago) Time: Don’t ask. 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. |