Theories on the Origin of Life PDF

Theories on the Origin of Life Theory of Spontaneous Generation ○ It states that living things just suddenly came into existence. ○ It said that living things can spontaneously arise from non-living things. ○ Aristotle is one of the believers from this theory ; He sa...

Theories on the Origin of Life Theory of Spontaneous Generation ○ It states that living things just suddenly came into existence. ○ It said that living things can spontaneously arise from non-living things. ○ Aristotle is one of the believers from this theory ; He said all things are full of soul and so matter generates life and that he documented observations that supported these ideas like maggots in decaying meat ○ Disproved by Francesco Redi in 1668 by showing how maggots came from flies not decaying meat. ○ Disproved once again by Louis Pasteur with a swan-necked flask experiment. Theory of Panspermia ○ Theorizes that microorganisms can be transported through space and land on another planet. ○ states that life began from outer space and that comets delivered life to Earth ○ shows that bacteria can survive being fired at high speeds, which is similar to the conditions experienced by material on Mars. Primordial Soup Theory ○ Oparin and Haldane ; 1929 ○ Compounds such as Hydrogen, Water, Ammonia, methane and carbon dioxide were present in the condition. ○ Compounds were synthesized due to the presence of energy in the environment such as the lightning, volcanoes, ultraviolet light forming chemical building blocks of life. ○ Miler Urey Experiment ; the first attempt to simulate ancient Earth conditions in lab to test the idea that life could arise from non-living theory ○ The hypothetical condition of the Earth 4 billion years ago. Abiogenesis Theory - the theory that all life started from inorganic molecules, which recombined in different ways due to energy input. Ex. Primordial Soup Theory The Uniqueness of the Earth Atmosphere - oxygen, nitrogen and carbon dioxide, crucial for supporting life.  Water - helps regulate the temperature, provides a habitat for aquatic life and is essential for chemical reactions that occur within living organisms. Magnetic Field - helps protect the planet from harmful solar winds and cosmic radiation Plate Tectonics - help recycle nutrients and minerals from the Earth’s crust Distance from the Sun - Earth is located in the habitable zone around the sun, where the temperature is just right for liquid water to exist on the planet’s surface. What we know about Life, so far 1. All known living things are made of cells. The cell is the fundamental and structural unit of all living things. 2. All living things can reproduce for their survival. They contain hereditary information which is passed off to offspring 3. All living things generally have the same composition chemically. Energy flows in ALL life.