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213
First hypothesis: Creationism
It establishes that a Godcreated life. This statement is written in sacred books. For example, in The West, some people still believe in that fact, they approve the Bible. -
314
Second hypothesis: spontaneous generation
Aristotle made a summary of spontaneous generation's ideas.
-Life can arise from vegetables, organic matter which had gone off, and from inorganic matter. -
Second hypothesis: spontaneous generation. Refutation.
He made an experiment in 1665 He prooved that maggots came from flies, spontaneous generation was false. -
Second hypothesis: spontaneous generation. Refutation.
-Lazzaro Spallanzani reviewed Redi's data. -He constructed his own experiment by placing broth in each of two separate bottles, boiling the broth in both bottles, then sealing one bottle and leaving the other open. Days later, the open bottle had small living things. -
Second hypothesis: spontaneous generation. Refutation.
He designed several bottles with S-curved necks. He put broth inside one bottle, and he boiled it. The conclusion was that there was no life in the jar for one year. Then, he broke the top of the bottle, so broth was exposed to the air more directly, and life-forms in the broth arised in a few days. -
Third hypothesis: Panspermia theory.
It states that the "seeds" of life exist all over the Universe. Some people believe that life on Earth may have originated through these "seeds". Svante Arrhenius was the greatest supporter of this theory. -
Third hypothesis: Panspermia theory. Drawbaks
However, panspermia doesn't explain how life was formed in the planet where meteorites came from. -
Fourth hypothesis: Chemical Evolution Theory of Life’s Origins.
In 1924, Oparin suggested that chemical compounds of the primitive atmosphere were important for the organic compounds to arise. Tiny molecules such as H2O,CH4,NH3... formed prebiotic molecules due to the sun's energy and thunderstorms. Then, they became aminoacids or nucleic acids. Nowadays, it's the most important theory. -
Fourth hypothesis: Chemical Evolution Theory of Life’s Origins.
The scientist Miller simulated Oparin's hypothesis through his experiment. He discovered that organic compounds arised from CH4, NH3, H, H2S, water steam and electric discharges. -
Fifth Hypothesis: Mineral Genesis.
It states that the first polymeres arised from clays. They attracted simple molecules and joined them easier. -
Sixth hypothesis: Hydrotermal springs.
Some scientist think that life was originated in the oceans, specifically in hydrotermal springs(close to oceanic ridges). -
Seventh Hypothesis: RNA's World.
It says that RNA was the first biomolecule appeared. It was originated in the primitive seas, which contained aminoacids and proteins. RNA evolutionated, and it formed the DNA. RNA is not the most important molecule. -
Intelligent design.
It says that Universe was intelligently designed. -
Bibliography
http://science.howstuffworks.com/innovation/scientific-experiments/scientific-method5.htm
http://es.wikipedia.org/wiki/Diseño_inteligente
http://myprofeciencias.wordpress.com/2011/01/31/teoras-del-origen-de-la-vida/
http://benitobios.blogspot.com.es/2007/08/generacin-espontnea.html
http://www.ojocientifico.com/2011/05/29/teoria-creacionista-o-fijista
http://www.wordreference.com
http://www.infoplease.com/cig/biology/spontaneous-generation.html
http://www.panspermia-theory.com/
-CMC's book
