Earth origin of life

Walker, J. C. G. 1985. Carbon dioxide on the early Earth. Origins of Life and Evolution of the Biosphere, 16, 117-127. 

A. Keefe and S. L. Miller. Potentially pre-biotic syntheses of condensed phosphates. Origins of Life and Evolution of Biospheres, 26 (1996), 15-25 but see also D. Glindemann, R. M. de Graaf and A. W. Schwartz. Chemical reduction of phosphate on the primitive earth. Origins of Life and Evolution of Biospheres, 29 (1999), 555-61. 

Deamer, D. W. (1986). Role of amphiphilic compounds in the evolution of membrane structure on the early earth. Origins of Life and Evolution of Biospheres, 17, 3-25. 

I think a (at least basic) understanding/appreciation for chemistry is essential to really understanding early earth / origins of life, and understanding where we came from is a good reason to study chemistry. ... 

Scientists still do not have a satisfactory explanation for how the first self-replicating living organisms appeared on Earth. Origin-of-life theories continue to be an area of active scientific research. 

Early students of the origin of life were misled because they believed that Earth was very young, in part because no methods were available for dating ancient events. Today, suitable methods exist for determining the age of materials that are billions of years old, and the fossil record of ancient organisms has vastly improved. The evolution of living organisms... 

Chang, S., Desmarias, D., Mack, R., Miller, S. L., and Strathem, G. E. (1983). Prebiotic organic synthesis and the origin of life. In "Earth s Earliest Biosphere, Its Origin and Evolution" (J. W. Schopf, ed.), pp. 53-88. Princeton University Press, Princeton, New Jersey. 

The deciding impulse which introduced biogenesis into scientific discussion came from Russia. After the upheavals of the civil war, that country was the subject of worried observation by the rest of the world. It was assumed that no great scientific achievements would be possible there. Then, in 1924, a book on the material basis of the origin of life on Earth appeared in Red Russia . Its author was Alexandr Ivanovich Oparin (1894-1980) from the Bakh Institute of Biochemistry in Moscow (Oparin, 1924). Basically, the Oparin hypothesis makes the following assumptions ... 

The question of the origin of life on Earth leads directly to the question of the formation of our planet, of the solar system and of the universe. The ancient philosophers, as we have seen, attempted to answer such questions, but the models which we discuss and argue about today were proposed by scientists only in the last century. 

While accepting the high quality of these results, Everett L. Shock from the Department of Earth and Planetary Research of Washington University, St. Louis, poses the critical question as to whether the many simulation experiments really help us in answering the question of the origin of life on Earth (Shock, 2002). 

Maurette M (1998) Micrometeorites on the early earth. In Brack A (Ed.) The Molecular Origins of Life. Cambridge University Press p 147... 

Zubay G (2000) Origins of Life on the Earth and in the Cosmos 2nd Ed. Academic Press, San Diego, New York... 

Fe-S complexes have important functions in today s living systems, in enzymes such as the ferredoxins and oxidoreductases, as well as in electron transport proteins. It is striking that these redox reactions mainly involve elements and compounds such as CO, H2 and N2, which were probably also components of the primeval Earth s atmosphere. Thus, the assumption of an active involvement of Fe-S clusters in a (hypothetical) Fe-S world in processes which finally led to biogenesis appears completely reasonable We now have a background to the theory of the chemoau-totrophic origin of life . 

Miller SL, Orgel LE (1974) The Origin of Life on the Earth. Prentice-Hall, Englewood Cliffs NY Miller SL, Bada JL (1988) Nature 334 609... 

One thing seems clear. As R. Shapiro put it so well in his book Origins A Skeptic s Guide to the Creation of Life on Earth In the origin of life, however, if no surprises were forthcoming, that would be the most surprising result of all. ... 

The decision to write a book on the origin (or origins) of life presupposes a fascination with this great problem of science although my first involvement with the subject took place more than 30 years ago, the fascination is still there. Experimental work on protein model substances under simulated conditions, which may perhaps have been present on the primeval Earth, led to one of the first books in German on Chemical and Molecular Evolution Klaus Dose (Mainz) had the idea of writing the book and was my co-author. 

Fig. 1.12. One hypothesis of the evolution of oxygen in the atmosphere in relation to the origin of life and the evolution of higher organisms. (From Earth (4th edn) by Press and Siever. Copyright 1986 W.H. Freeman and Company, with permission.)...

Our mission is to explore the molecular universe with an understanding of all of the local molecular environments and constrain possible chemical reactions using the concepts of physical chemistry. With such a wide brief we need a focus and I have chosen the origins of life on Earth and on all planets - astrobiology. 

There is no one correct theory for the origin of life on Earth or any habitable planet, although many have been presented. The current set of ideas is summarised in Figure 1.5. Aside from the theory of creation, which seems particularly hard to test, the testable theories of the origins of life divide into two extraterrestrial or panspermia, the theory that life was seeded everywhere somewhat randomly and terrestrial, that life originated de novo on Earth or other habitable planets around other stars. The theories of terrestrial origin are more favoured but the recent discovery of habitable planets and life within any solar system suddenly makes panspermia more likely. 

Extraterrestrial origins of life Terrestrial origins of life Life was delivered to the Earth (or any planet) by meteorites of cometary material, leading to the idea of panspermia The molecules of life were built on Earth, perhaps in the primordial soup or little warm pool... 

Much of the electromagnetic spectrum has been used to investigate the structure of matter in the laboratory but the atmospheric windows restrict astronomical observations from Earth. Irritating as this is for astronomers on the ground, the chemical structure of the atmosphere and the radiation that it traps is important to the origins of life on Earth. The light that does get through the atmosphere, however, when analysed with all of the tools of spectroscopy, tells the molecular story of chemistry in distant places around the Universe. 

Of the alkenes (Figure 5.5) only ethene has been detected and of the aromatics only benzene has been seen unambiguously surprisingly propene has not been seen despite its well-understood microwave spectrum. Of interest to the origins of life is the onset of polymerisation in HCN to produce cyanopolyynes. These molecules could provide a backbone for the formation of information-propagating molecules required for self-replication. The survival of these species in a planetary atmosphere depends on the planet oxidation would be rapid in the atmosphere of today s Earth but what of the early Earth or somewhere altogether more alkane-based such as Titan ... 

Chyba C. F. and McDonald G. D. (1995). The origin of life in the solar system current issues. Annual Reviews of Earth and Planetary Science 23 215. 

McClendon J. H. (1999). The origin of Life. Earth-Science Reviews 47 71. 

In the study of the origin of life on earth, the element carbon is essential. Carbon is a required component of the fundamental molecules of life amino acids, bases, and sugars. In addition, a large variety of carbon compounds is necessary in the complex biochemical cycles of living organisms. The physical and chemical nature and geometry of the carbon atom make it well suited to form the vast array of molecules involved in the chemistry of life. 

The first concerns the origin of life on earth as we know it, of our biological world. The second considers the possibility of extraterrestrial life, within or beyond the solar system. The third question wonders why life has taken the form we know, and it has as corollary the question whether other forms of life can (and do) exist is there artificial life It also implies that one might try to set the stage and implement the steps that would allow, in a distant future, the creation of artificial forms of life. 

Was Nature s selection of these stereochemical structures a random event, or was it the consequence of determinate processes Although the presence of amino adds and other organic molecules on primitive Earth has been attributed to both endogenous and exogenous sources, [5,6] the origin of the chiral bias of prebiotic molecules remains a fundamental mystery. A mystery perhaps even more central to the origin of life is the mechanism that brought into dominance and survival any putative small chiral molecular excess on early Earth. 

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