BIOL 1202 Chapter : History Of Life On Earth
Document Summary
How did life begin on the planet: at one point there was no life, and then all of a sudden, there was. A few centuries ago: people thought that new living things appeared all of the time, the theory was known as spontaneous generation of life , 1609. There is a tree frequently observed in scotland. From this tree leaves are falling; upon one side they strike the water and slowly turn into fishes; Spontaneous generation refuted: mid-1800"s louis pasteur broth in flask is boiled to kill pre-existing microorganisms. As broth cools, condensing water collects, sealing the mouth of the flask. He was able to show through this experiment that microorganisms could only grow in the solution if it was exposed to outside air. One explanation was that the air around the flask was the source of the organisms itself. It is assumed that this is how life originally began.
