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Which came first? The chicken or the egg? The Mystery of Life's Origin

Explaining the origin of life is a special problem in science, because we are dealing with unique and unrepeatable events, and we don't have the usual empirical evidence, since no observers were present. It is like forensic science, in that we have to deal with circumstantial evidence. For some, this removes the area from the domain of science, because they believe statements not checked by direct observation are not science.

We are reminded of fictional detective Perry Masons comments in "The Case of the Perjured Parrot" on the problem of only having circumstantial evidence:

"That's the worst of circumstantial evidence, the prosecuting attorney selects only those observations which, in his opinion, are significant. Once he comes to the conclusion the defendant is guilty, the only facts he considers significant are those which point to the guilt of the defendant".

A brief history of the theory of molecular evolution:

1668	The rejection of spontaneous generation. Redy showed that flies emerged from meat only upon previous contact with flies.
1864	Pasteur confirmed that micro-organisms emerge only after contact with other air borne micro-organisms.
1871	Darwin speculated about the possibility of a warm little pond where nonliving chemicals could come together to form the first life.
l924	Oparin revived the idea of spontaneous generation under prebiotic conditions.
1928	Haldane proposed the theory of chemical evolution, and some possible prebiotic conditions. He suggested that ultraviolet light could interact with atmospheric water, carbon dioxide and ammonia to produce sugars and amino acids. These could be precursors for more complicated organic molecules, which might eventually produce living cells.
1947	Bernal suggested that the adsorption of simple monomers on clay surfaces could give concentrations high enough to allow for polymerization by condensation reactions. They might also provide protection for biopolymers from destruction by UV light.
1952	Urey proposed that the prebiotic atmosphere was reducing, i.e. hydrogen rich, as is the case in the present day atmospheres of larger planets. This condition would prevent biopolymers from oxidizing.
1953	Watson & Crick, concerned with lifes structure, proposed the double helix structure for DNA. Stanley Miller (Ureys graduate student) offered experimental support for the formation of amino acids from a primordial atmosphere of water, ammonia, methane and hydrogen. Thus the idea that simple molecules interacted at random in a primordial pool, developed into a fully fledged theory of chemical or molecular evolution to account for the postulated pre-biological phase of the evolution of life.
1966	The role of randomness was challenged by the use of computers, which were used the simulate the 10 billion year time span assumed to be needed for molecular organization. Probability calculations based on information theory showed that the odds against the chance formation of highly complex molecular structures, such as proteins and nucleic acids, are vanishingly small. Chance and randomness were recognized as unlikely candidates in the quest to find a mechanism for lifes origin. But calculations on the probability of the chance formation of molecules were not taken seriously by many because of the uncertainty of the chemical pathways involved.
1970's	By the 1970's new calculations on the spontaneous synthesis of complex molecules could be done without regard to the path that led to their development. The Nobel Prize winner Ilya Prigogine concluded that The probability that a macroscopic number of molecules assembled to give rise to the highly ordered structures characterizing living organisms is vanishingly small.... Michael Polyani claimed that if only the bonding properties of atoms accounted for the structure of DNA, it would not have significant information content, and its code-like character would be neutralized by an overwhelming redundancy. The view that the intrinsic properties of molecules was somehow responsible for their increasing complexity, led in the mid 1970s to the idea that some, as yet undiscovered, inherent property of matter might be directing chance.
1974	Miller tried again to put origin of life studies on an experimental footing. He was so confident of this theory, that he proposed that the first Mars landing be mainly directed to experiments to detect living organisms. These experiments found no evidence that life had ever existed on Mars. Nor did the Voyager 1 fly by of Jupiter and Saturn.
1980's	The 1980s onwards brought interesting developments in the study of self- replicating RNA, where small single strands of RNA, are converted into a double helix strand of RNA, without a catalyzing enzyme. However such self- replication seems to stop after a single step, and does not lead to anything that could be described as a viable life form. Also, microorganisms were discovered in Italys volcano island that grew at temperatures of 1000C or greater. Very recently, two large planets in the Virgo and Ursa Major constellations, whose environments might be able to support life, and whose surface might allow the formation of water, have been discovered.

The Uniqueness of Human Life

The ability of atoms to form the molecules of life needs very fine tuning in a wide range of properties. There is a major contrast between synthesizing amino acids and the consistent failure to make molecules like DNA. This is because of the magnitude of the information contained in such highly ordered complex structures.

We do not know of any way of overcoming the information barrier to make anything that could be called a living system. Appeals to time and chance as a way around this problem are hard to accept because of the staggeringly low probability of forming the molecules of life, even allowing for times well over five billion years. All attempts to do so are highly dependent on the design and designer of the experiment. And laboratory synthesis never produces only the 'left handed' type of protein always found in the molecules of life.

The existence of higher forms of life with all its complexity remains an extremely improbable event. As science discloses the many parameters which are 'just right for life' on this warm wet niche in the universe that we call earth, it provides more challenging evidence for the reality of a personal Creator. Christians are not surprised at any of this, since Romans 1:20 in the New Testament says that "God's invisible power and divine nature has been clearly seen in what has been made, so we are without excuse."

Science Shorts features two minute radio spots that make the world of science accessible in an entertaining way.

Genesis Quest and Science Shorts are sponsored by World of Science, and edited by Dr. David A. Humphreys, Emeritus professor of Chemistry at McMaster University in Canada.