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ARGUMENTS OF EVOLUTION IN BIOLOGY TEXTBOOKS: Origin of Life

ARGUMENTS OF EVOLUTION IN BIOLOGY TEXTBOOKS: Origin of Life. Suzanne Phillips Loma Linda University Loma Linda, California. INTRODUCTION. Three possible explanations for the beginning of life : God (or an Intelligent Designer ). - OR- Random chemical reactions + Evolution. INTRODUCTION.

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ARGUMENTS OF EVOLUTION IN BIOLOGY TEXTBOOKS: Origin of Life

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  1. ARGUMENTS OF EVOLUTION IN BIOLOGY TEXTBOOKS:Origin of Life Suzanne Phillips Loma Linda University Loma Linda, California

  2. INTRODUCTION • Three possible explanations for the beginning of life: • God (or an Intelligent Designer). - OR- • Random chemical reactions + Evolution.

  3. INTRODUCTION • Abiogenesis, or informally the origin of life,is the natural process by which life arises from non-living matter, such as simple organic compounds. The transition from non-living to living entities was not a single event, but a gradual process of increasing complexity that involved molecular self-replication, self-assembly, autocatalysis and cell membranes.Although the occurrence of abiogenesis is uncontroversial among scientists, there is no single, generally accepted model for the origin of life, and this article presents several principles and hypotheses for how abiogenesis could have occurred • -Wikipedia, “Origin of Life”

  4. INTRODUCTION • Until 19th century, the earth, nature and organisms were thought to have been created by an intelligent designer (God). • In the 19th century, Darwinism introduced naturalism as the dominant scientific paradigm. Design was explained as the result of random natural processes and natural selection.

  5. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • DARWIN • Simple forms produced new forms • He did not explain the origin of life. • 1870-1890 • Cells consist of a simple substance called protoplasm that could be easily formed combining simple chemical products like CO2, O2, N2.

  6. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • HAECKEL • Cells arise and form through a process similar to inorganic crystallization. • T. H. HUXLEY • A simple two-step method of chemical recombination could have produced the first cell. • Simple protoplasmic cells may be formed by combining several chemical compounds through spontaneous reactions.

  7. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • OPARIN (1922-1938) • There is no fundamental difference between a living organism and a lifeless object. • Life’s complex characteristics and features must have arisen throughout the process of evolution. • In the beginning there were organic compounds in simple solutions. • Gradually, as a result of growth and increasing molecular complexity, new properties arose and a new chemical-colloidal order was established over the simpler organic chemical reactions. • This process brought about biological order. • Competition, rate of growth, struggle for life and natural selection determined the organization of the present living organisms.

  8. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • The origin of life question consists of three sub-questions: • RAW MATERIALS: Where did the original organic raw material come from? ABOVE, BEYOND, or BELOW • ORGANIZATION: How did this raw material spontaneously organized to form the first object that could be categorized as “living”? • SURVIVAL: How did the first living object survived the harsh conditions in the primitive solar system?

  9. THE “ABOVE” HYPOTHESIS • Organic raw matter formed in the primitive atmosphere. • It is based on the assumption that the atmosphere of the primitive earth was similar to the atmosphere of Jupiter, which is rich in methane and ammonia. • MILLER’S experiment on the origin of the first organic molecules.

  10. MILLER'S EXPERIMENT Conducted in 1952by Stanley Miller, with assistance from Harold Urey

  11. MILLER'S EXPERIMENT • Miller’s intention was to re-create hypothetical conditions for the origin of life. • He wanted to obtain the life’s building blocks (molecules): • Amino acids • Fat acids • Nucleotides (for DNA, RNA) • Sugars

  12. MILLER'S EXPERIMENT • Life’s building blocks (molecules): • Amino acids • Fat acids • Nucleotides (for DNA, RNA) • Sugars

  13. MILLER'S EXPERIMENT MILLER'S EXPERIMENT • Assumptions: • Gas mixture containing methane, ammonia, water vapor, and hydrogen (assumed to be similar to the primitive atmosphere. • High voltage electrical discharges (similar to short wave UV). • Simulation of environmental processes.

  14. MILLER'S EXPERIMENT MILLER'S EXPERIMENT • After two days: • Production of 2% of various types of amino acids, including glycine and alanine, and also sugars, tar, and other unidentified organic products.

  15. MILLER'S EXPERIMENT • Thanks to Miller, chemical evolution is now presented in textbooks as the scientific explanation for the origin of biomolecules and life. • It is a naturalistic explanation • Millers experiment has been replicated and modified hundreds of times. • Different atmospheres • Different energy sources • However, results are frequently the same • Orgel and Lohrmann indicated the required conditions to simulate the prebiotic synthesis of organic moecules in lab experiments: • Gas mixture containing methane, ammonia, water vapor, and hydrogen (reducing conditions) • High voltage electric discharges

  16. PROBLEMS WITH MILLER’S MODEL • Miller assumed that the prebiotic atmosphere had the same composition as stellar gas clouds. • However this idea is now rejected. • Miller believed that the prebiotic atmosphere consisted of • Methane, ammonia, H2. • No free O2. • Researchers now believe that the primitive atmosphere was not reducing but neutral (H2, N2, CO2). • However, when those gases are used in experimental simulations, the amount of organic molecules obtained is considerably reduced.

  17. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • The original mixture of gases had no O2, but O2 was obtained in the final products. • Both the absence and the presence of O2are a problem for Miller’s model: • Most scientists now believe that O2 must have been present in the atmosphere when the first organic molecules were being formed. • This is a problem because O2 destroys the organic molecules that might be formed. • Even a little amount of O2 destroys biomolecules by oxidation. • Amino acids are found in very low concentration • Most amino acids formed are non-proteinic amino acids, which cannot be used to build up cellular structures and enzymes • All amino acids obtained, except glycine, are racemic. • No peptides found. • No polymerization.

  18. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • Short and long wave UV radiation is present in any realistic atmosphere. • Simulation experiments use only short wave UV light. • Presence of long wave UV light quickly destroys biomolecules.

  19. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • It is assumed that electrical storms happened frequently in the early atmosphere. • However, it is doubted that they could have provided the amount of electricity used in Miller’s experiment.

  20. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • The idea of a primordial soup is assumed, but not shown in the geologic record. • No evidence for that idea.

  21. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL Left handed and Right Handed molecules

  22. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL L- and D-Amino Acids. Amino acids can occur in L- and D-forms, but only L-forms are used by cells to make proteins. Every amino acid (except glycine) can occur in two isomeric forms, because of the possibility of forming two different enantiomers (stereoisomers) around the central carbon atom.

  23. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL You can see in the above image the only difference is the position of the hydroxyl group (OH) on the carbon chain. They are mirror images of the other but they do not overlap. L-Glucose has to be made in a lab, whereas D-Glucose is naturally occurring.

  24. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • Even if useful organic molecules were formed, energy is needed to bring cells together. • The energy required to drive (some but not all) reactions forward is even more likely to break them apart. • This is particularly true for complex molecules that tend to quickly break down to simple compounds. • For this reason, lab simulations include a trap to catch the organic compounds before they can be exposed to energy sources. • But in the primordial ocean these molecules would not be protected.

  25. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • The gas mixture that Miller used in his experiment has been questioned by many researchers. • Apart from Miller’s initial success, little or no progress since. • A detail examination shows that these experiments are not related to the origin of life and cells. • Complex cellular structures are essential and a requisite for life. • Origin of life requires a level of complexity that unguided chemical processes cannot achieve. • Abiogenesis is merely a myth, not an observable process.

  26. PROBLEMS WITH MILLER’S MODEL PROBLEMS WITH MILLER’S MODEL • Miller had to make multiple adjustments to his experiment before any satisfactory result was achieved. • What Miller’s experiment shows is that even the most simple results require manipulation by an intelligent designer. • Since the original experiment in 1953, numerous improvements, modifications, and extensions have been attempted, but no further result achieved. • Life is irreducibly complex.

  27. Warm Little Ponds 2014 Scientific American Kranendonk, Daemer, Djokic

  28. THE “BEYOND” SCENARIO • OPARIN (during 1922-1938) • Based on the recent discovery of methane in the atmosphere of the giant planets, Oparin assumed that the primitive earth had a strongly reducing atmosphere, containing methane, ammonia, hydrogen, and water, which were the raw material for the origin of life. • Origin of life on earth as a result of combination of organic raw material or even microorganisms coming from the outer space

  29. THE “BEYOND” SCENARIO

  30. THE “BEYOND” SCENARIO • The famous astronomer Fred Hoyle supports this scenario. • More than 135 different organic molecules have been found in outer space. • 2-13 C molecules. • Little evidence to support the “beyond” scenario: • Very few of those molecules are similar to any molecule that is found in the living matter. • This model only shifts the origin of life problem to another planet.

  31. THE “BELOW” HYPOTHESIS • Two hypothesis: • Deep ocean hydrothermal vents. • Hot volcanic ponds. • This idea is based on the occurrence of thermophile microbes found in deep ocean hot springs. • Molecular analysis suggest that these microbes’ DNA is very primitive, which related them to an alleged common ancestor. • However, this primitiveness is an assumption.

  32. Darwin's Warm Little Ponds "But if (and oh what a big if) we could conceive in some warm little pond with all sorts of ammonia and phosphoric salts, light, heat, electricity etcetera present, that a protein compound was chemically formed, ready to undergo still more complex changes [..] " ~Charles Darwin, in a letter to Joseph Hooker (1871)

  33. THE “BELOW” HYPOTHESIS • Darwin: life could have emerged in “little warm ponds”. • Some experiments show that some biological molecules can polymerize under control lab conditions similar to volcanic environments. • Biophysist David Deamer (University of California, Santa Cruz) has carried out experiments in small warm ponds in volcanic regions in Kamchatka (Russia) and Mount Lassen (California). • In Kamchatka, recent volcanic activity had erased all evidence of life in the volcanic ponds. • Deamer added a can of “primordial soup” that contained what they assumed as the first organic molecules needed for the origin of life. • He also added fat acids needed to form the first rudimentary cell membranes. • RESULT: some hours later most of the added material had disappeared from the water.

  34. THE “BELOW” HYPOTHESIS • Observations indicate that amino acids and DNA adhere to the surface of clay particles in volcanic ponds. • Clay could have played a role in catalyzing chemical reactions related to the origin of life. • Some organic compounds so strongly adhere to clay particles that they could not participate in any further chemical reactions (Morelle 2006). • Experiments in volcanic ponds indicate that life could not have originated in such hostile environments.

  35. THE “BELOW” HYPOTHESIS • Amino acid polymerization onto proteins requires removal of water. • Therefore, aquatic environments are thermodynamically unfavorable for many key metabolic reactions, unless they are guided and protected. • If the primitive ocean was so saline as the current ones, salt would have inhibited many key prebiotic reactions.

  36. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • The origin of life question consists of three sub-questions: • RAW MATERIALS: Where did the original organic raw material come from? ABOVE, BEYOND, or BELOW • ORGANIZATION: How did this raw material spontaneously organized to form the first object that could be categorized as “living”? • SURVIVAL: How did the first living object survived the harsh conditions in the primitive solar system?

  37. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • The origin of life question consists of three sub-questions: • RAW MATERIALS: Where did the original organic raw material come from? ABOVE, BEYOND, or BELOW • ORGANIZATION: How did this raw material spontaneously organized to form the first object that could be categorized as “living”? • SURVIVAL: How did the first living object survived the harsh conditions in the primitive solar system?

  38. THE MOST IMPORTANT PROBLEM • Even if we could prove that biomolecules were formed by random chemical reactions in realistic prebiotic conditions, still there will be the problem of assembling those biomolecules onto functional, information-bearing biomolecules. • NO PEPTIDES formed

  39. THE PROBLEM OF BIOLOGICAL COMPLEXITY • When Miller carried out his experiment, little was known about the complexity of proteins and DNA. • Proteins and DNA are highly complex, 3-D biomolecules. • A complex of molecule chains, bonds. Has 290,909 Peptide bonds!!

  40. THE PROBLEM OF MOLECULAR SPECIFICITY • Protein function depends on the complex and specified order of amino acids. • A little alteration of the order can result in the loss of function, malfunction, and disease.

  41. THE MOST IMPORTANT PROBLEM ORIGIN OF LIFE = ORIGIN OF BIOLOGICAL INFORMATION • Since Miller’s experiment, three naturalistic explanations have been suggested to explain the origin of biological information. • Randomness • Prebiotic natural selection • Chemical necessity

  42. ORDERAND INFORMATION • There is a qualitative difference between “order” and “information”. • Salt crystals and tornados show order, but they store or convey no information.

  43. THE "RNA WORLD" MODEL • Life began in a “RNA world”. • RNA formed by four bases: U, C, A, G. • They can be combined in any order. • All sequences are equally probable (or improbable).

  44. THE "RNA WORLD" MODEL • Sometimes RNA functions as enzyme –as a protein. • It has been suggested that RNAS could be able to auto-synthesize in the absence of proteins. • RNA could originated in the primitive earth before proteins or DNA. • This “RNA world” could have been the molecular craddle from which living cells could have emerged. • Nobody has shown how RNA could have formed before living cells appeared. • Many scientists reject the idea that life emerged in a RNA world. • The “RNA world” model does not solve the seuqence problem: the problem of explaining how information present in all functional RNA molecules originated.

  45. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • The origin of life question consists of three sub-questions: • RAW MATERIALS: Where did the original organic raw material come from? ABOVE, BEYOND, or BELOW • ORGANIZATION: How did this raw material spontaneously organized to form the first object that could be categorized as “living”? • SURVIVAL: How did the first living object survived the harsh conditions in the primitive solar system?

  46. NATURALISTIC EXPLANATIONS FOR THE ORIGEN OF LIFE • The origin of life question consists of three sub-questions: • RAW MATERIALS: Where did the original organic raw material come from? ABOVE, BEYOND, or BELOW • ORGANIZATION: How did this raw material spontaneously organized to form the first object that could be categorized as “living”? • SURVIVAL: How did the first living object survived the harsh conditions in the primitive solar system?

  47. CONCLUSION • Naturalistic models have not been able to explain the origin of biological information. • Matter properties are not sufficient to explain the origin of information. • Scientists can mix all chemical molecules necessary for life (proteins, sugars, enzymes, DNA, RNA, minerals, etc.) in a tube and yet produce no living cell. • Information systems (especially codes and languages) come from an intelligent source (what philosophers call “casual agent”). • We can detect past actions of an intelligent cause from the results of the information, even if the cause itself cannot be directly observed. • Although Miller’s experiment (and others similar) could not show how life could have originated by naturalistic means, they are still used as scientific answer to the question of how life arose.

  48. Accident or Design? • "Once we see that the probability of life originating  at random is so utterly minuscule as to make it  absurd, it becomes sensible to think that the favorable properties of physics, on which life depends, are in every respect deliberate.It is almost inevitable, that  our own measure of intelligence must reflect higher intelligence  - even to the limit of God.” Sir Fred Hoyle • Hoyle does not necessarily accept the  God of  the Bible. He simply says that there must  be  some  higher intelligence on the level of God.

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