BIOL 1202 Lecture Notes - Lecture 25: John Burdon-Sanderson, Harold Urey, Alexander I Of Russia
Document Summary
A time line for planet earth: the earth is very old, about 4. 6 billion years old, as earth cooled the oceans formed. How did life originate: was it really spontaneous generation, something from nothing, the building blocks of macromolecules can be formed from nonliving matter if the conditions are right. In the 1920"s and 1930"s two researchers: john burdon sanderson (j. b. s. ) Haldane in england: aleksandr i. oparin, a russian biochemist, Independently hypothesized that the atmosphere of the primitive earth was probably very different from today"s. Early atmosphere had little or no oxygen rich in hydrogen, methane, other hydrocarbons and ammonia: most of these can come from volcanic sources. This process of chemical evolution is called prebiotic evolution: evolution before life existed. The hypothesis of abiotic formation of organic molecules was tested in 1953 in the laboratory of stanley miller and harold urey (see fig. A variety of organic compounds were created: amino acids, short proteins, sugars, nucleotides fatty acids.
