Organic Soup Origin of Life Models Flashcards
And early theories
What is the Spontaneous Generation Theory?
Living organisms can be generated spontaneously from nonliving organic molecules
Who refuted Spontaneous Generation? When?
Louis Pasteur, 1859
There were others, earlier, but he used an easily reproduced and explained experiment
How was Spontaneous Generation proven false?
Swan neck flask experiment
Germs in the atmosphere contaminate exposed broth. When the germs are unable to get through the open ended swan neck (trapped in the dip in the neck), the broth stays uncontaminated.
What two common components were necessary in prebiotic earth to form life, according to Organic Soup Models?
1 Chemical precursors (small chemical species needed to react to form larger compounds)
2 Mechanism for precursors to form into larger compounds and eventually organics
Who first stated the Warm Little Pond theory?
Darwin
6 key concepts of Warm Little Pond
1) small - restricted environment to allow for concentration of precursors- mechanism for polymerization
2) warm - higher temps promote faster/more reactions
3) diversity of chemical precursors
4) multiple energy sources (light, heat, electricity)
How can we test Warm Little Pond theory?
We can’t. Any precursors would be instantly consumed by life present in the environment
Primordial Soup theorists
1924 - Oparin
1928 - Haldane
4 components/stages of Primordial Soup theories
reducing conditions in an anoxic atmosphere
precursors = methane (CH4), hydrogen gas (H2), ammonia (NH3)
energy input = sun, lightening, volcanic heat , UV radiation (Haldane, specifically)
organics would rain out of atmosphere once formed
3 Key concepts of Primordial Soup theories
1) atmospheric conditions different than it is has been for most of Earth’s existence
2) photochemistry performs organic synthesis
3) chemical evolution follows laws of physics and chemistry
3 potential Flaws with Primordial Soup theories
1) Atmosphere is not dilute solution
2) no mechanism for concentration
3) was atmosphere reducing enough to bring about initial polymerization and formation of organics?
Spark Synthesis
experiment mid 1900’s to test Primordial Soup theories
What was result of Spark Synthesis
amino acids formed from precursor chemical species, but required very reducing conditions
Why is hydrogen cyanide (HCN) important for early life?
Intermediary species between inorganic compounds and organic compounds
What would need to be present in atmosphere to form HCN?
energy = lightning
nitrogen gas
Carbon monoxide
reducing atmosphere
