BENCHMARK SC.912.L.15.8
Describe the scientific explanations of the origin of life on Earth.

Items may address the conditions required for the origin of life on
Earth but may not require specific knowledge of the age of Earth or
its eras, periods, or epochs.
 Items may assess how contributions of scientists such as Pasteur,
Oparin, Miller and Urey, Margulies, or Fox aided in the development
of the scientific explanation of the origin of life but will not assess
what each scientist contributed.
 Items assessing the origin of organic molecules, chemical evolution,
and/or eukaryotic cells should be conceptual.
 Items may refer to the endosymbiotic theory but may not assess the
term in isolation.
 Items assessing a scientific claim are limited to the scientific
explanations of the origins of life on Earth.
Oparin
Metabolism evolved before life and is a precursor for life.(metabolism occurred first) energy is essential
Pasteur
Creationists often claim that Louis Pasteur disproved spontaneous generation and hence any naturalistic
origin of life. This article shows what Pasteur really demonstrated and gives a history of the subject from
early ideas of spontaneous generation to modern ideas about the origin of life. Disprove spontaneous
generation.
Margulis
In addition to her primary explanation on the origin of mitochondria and chloroplasts, Dr. Margulis also
proposed that eukaryotic flagella and cilia derived from endosymbiotic spirochetes.( cells unite with
other cells to make a mutualistic relation) film on endosymbiosis
https://www.youtube.com/watch?v=RaAM8qQcs6E
Fox
Sidney Walter Fox (24 March 1912 - 10 August 1998) was a Los Angeles-born biochemist responsible for
discoveries on the origins of life. Fox explored the synthesis of amino acids from inorganic molecules,
the synthesis of proteinous amino acids and amino acid polymers called "proteinoids" from inorganic
molecules and thermal energy, and created what he thought was the world's first "protocells" out of
proteinoids and water. He called these protocells "microspheres" and they have now been named
"protobionts." Fox believed in spontaneous generation of life and suggested that his experiments
possessed conditions that were similar to those of primordial Earth. In his experiments, he
demonstrated that it is possible to create protein-like structures from inorganic molecules and thermal
energy (abiogenesis)
Formation of the Earth
The Earth primitive atmosphere (gases) composed of:
1.
2.
3.
CO2 Carbon Dioxide =====
CO Carbon Monoxide
N
Nitrogen
4.
HCN
5.
6.
7.
8.
H20 Water
NH4 ammonia
H2 hydrogen
CH4 Methane
=====
=====
Cyanide
===
No Oxygen( anaerobic)
===
=====
=====
=====
Miller-Urey Experiment
The recycled water has organic amino acids.
 Amino acids are the tools for life (first organic molecules)
 Amino acids are the “Beginning of life”
 Modern experiments similar to Miller and Urey’s demonstrate that simulating conditions thought
to exist on early Earth can produce bases needed for RNA
One of the accepted scientific theories describing the origin of life on Earth is known as
chemical evolution. According to this theory, which of the following events would need to
occur first for life to evolve?
A. onset of photosynthesis
B. origin of genetic material
C. synthesis of organic molecules
D. formation of the plasma membrane