The abiotic chemical evolution of life follows 4 major steps:
1. the abiotic synthesis and accumulation of small organic molecules, or monomers, such as amino acids and nucleotides;
2. the joining of these monomers into polymers, including proteins and nucleic acids;
3. the aggregation of abiotically produced molecules into droplets, protobionts, that had chemical characteristics different from their surroundings; and
4. the origin of heredity. (Campbell)
To understand how this creation of life from abiotic material occured, we have to consider 2 critical ideas (F. Shu):
1. The extension of the idea of natural selection to chemical level.
2. The realization that the condition of the early Earth when life first arose must have been vastly different from present:
a) non-oxidizing atmosphere: present level of oxygen, which began to accumulate around 2.1 billion years ago with the presence of cyanobacteria, would have been lethal to primitive organisms
b) abundant resources produced non-biologically
c) long time scale without competition
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