Origin of Life

Theories and evidence for chemical biopoieses

Origin of Life and Early Life on Earth

Thematic Issue: Origin of Life and Early Life on Earth
1. Origin of Life on Earth: Prebiotic Synthesis
2. Continental Crust and Oceans on Ancient Earth.
3. On Carbon Monoxide in Comet Hale-Bopp.
4. On the Earliest Traces of Life on Earth.
5. On Earth's Earliest Fossils.
6. On the Evidence for Earth's Oldest Fossils.
7. On the Akilia Rocks and Earth's Earliest Life.
8. Early Earth: Carbonaceous Meteorites as a Source of Sugars
9. On the Origin of the Earth.
10. Life and the Evolution of Earth's Atmosphere.
11. On the RNA-World Hypothesis
12. Origin of Life: The Present Status of Chemical Theory

Evolutionary oscillation in prebiology: igneous activity and the origins of life. Entrez PubMed: "The processes of chemical evolution are responsible for the origin of life. Three such processes have special importance: oscillation, creation, and competition. An oscillation from one kind of environment to another provides a mechanism for instituting processes that can only take place under conditions far removed from equilibrium. Oscillating evolutionary processes are likely to have played an important part in the origin of life. It is a mistake to assume that life originated in any one environment. It did not arrive in a moment of time. It was the result of a long period of chemical evolution during which it passed through a variety of environments. Biopoesis took place in an environment in which a variety of different kinds of protolife were assembled and concentrated. One essential form of protolife involved in these processes is the protocell. The experiments of Fox suggest that the creation of protocells involves violent oscillations of temperature and hydration. Igneous activity is especially characterised by oscillating conditions. Volcanic eruptions consist of violent changes from one extreme condition to another. Temperatures, pressure, phase, concentration and hydration all oscillate violently, and are subject to shock pulses of many kinds. Protolife may well have passed through extremes of environment for wider that those that life itself can sustain. The most probable environment for the assembly of the various forms of protolife would be on mudbanks forming either at the mouth of streams draining regions of active vulcanicity, or round the edge of hot volclanic pools. In this situation one could fins concentrated not only the various stands of protolife necessary for the final act of biopoesis, but also perbiologically formed nutrients necessary as for the first eobionts. As soon as the first protocells start to grow, they start to compete with each other, and so initiate a new additional evolutionary process, that of natural selection. Only after such competition has been initiated is life itself likely to be established."
Sylvester-Bradley PC. Evolutionary oscillation in prebiology: igneous activity and the origins of life. Orig Life. 1976 Jan;7(1):9-18.

Impact frustration of the origin of life. : "One possible definition for the origin of life on Earth is the time at which the interval between devastating environmental insults by impact exceeded the timescale for establishing self-replicating proto-organisms. A quantitative relationship for the Hadean (pre-3,800 Myr ago) and Early Archean (3,800 to 3,400 Myr) impact flux can be derived from the lunar and terrestrial impact records. Also, the effects of impact-related processes on the various environments proposed for abiogenesis (the development of life through chemical evolution from inorganic materials) can be estimated. Using a range of plausible values for the timescale for abiogenesis, the interval in time when life might first have bootstrapped itself into existence can be found for each environment. We find that if the deep marine hydrothermal setting provided a suitable site, abiogenesis could have happened as early as 4,000 to 4,200 Myr ago, whereas at the surface of the Earth abiogenesis could have occurred between 3,700 and 4,000 Myr."
Maher KA, Stevenson DJ.Impact frustration of the origin of life.Nature. 1988 Feb 18;331(6157):612-4.

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