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Origin of Life: by Chance or by Design?

Origin of Life: by Chance or by Design?. By -. Swati Agarwal - 2884 Ayush Jain - 2888. Zoology Hons . 1 st Year ( SectionA ) Hansraj College Delhi University. The Nature of Life. Life

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Origin of Life: by Chance or by Design?

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  1. Origin of Life:by Chance or by Design?

  2. By - • SwatiAgarwal- 2884 • Ayush Jain - 2888 Zoology Hons. 1st Year (SectionA) Hansraj College Delhi University

  3. The Nature of Life • Life • During last 4 by adapted to many environments and physico-chemical conditions • Most organisms live at 1 atm and 0-40oC; Some Bacteria can live up to 1400 atm or -18 to 104oC • Unicellular Organisms vs Non Living Molecules (Amino acids, RNA (ribonucleic acid) • reproduction • growth via nutrients and energy • responds to outside stimuli • Share same genetic code • chemical uniformity • C, O, H, N, P >> nucleic acids, proteins, carbohydrates, fats

  4. Prokaryote vs. Eukaryote • small (1-10 um) vs large (10-100um) • No nucleus vs Nucleus • DNA in nucleoidvs Membrane bounded nucleus containing chromosomes made of DNA, RNA • Cell division direct (binary fission) vs mitosis and miosis • Rare multicellular forms vsMulticellular organism with extensive development of tissues

  5. Building Blocks: Pattern shared by all life • All Life: DNA => RNA => Protein • DNA architect plans for building (instructions to build proteins in the ribosome) transcribes information into RNA (Blueprint) • RNA messenger translates blueprint into proteins in the ribosomes • Genes code for specific proteins (enzymes) • Enzymes are proteins that control all chemical reactions • Order of nitrogenous bases (read in groups of 3) {A, T, C, G} determines the type of proteins made • Each group of 3 codes for a specific amino acid

  6. DNA: Our Genetic Code Spiral double helix of sugars and phosphate linked together by nitrogenous bases such as Thymine, Cytosine, Adenine and Guanine. A Gene is a portion of the DNA molecule that includes approximately 1500 base pairs and a Chromosome contains many genes

  7. The Origin of Life • 19th Century Ideas • life created supernaturally • cannot be proven scientifically • continually being formed by spontaneous generation of nonliving matter • untenable by numerous experiments • 20th Century • life generated spontaneously and evolved through different steps

  8. The Origin of Life • Origin of life is NOT an event • Origin of life is a continuous process • Stages • inorganic production of key simple organic molecules • production of more complex molecules that can synthesize more of the same molecule • development of a genetic code of self-replicating molecules (RNA,DNA,proteins) • production of the first cell by separation of these codes from the outer world by a membrane • Ocean environment by 4.0 by- fossils evident at 3.8by

  9. The Origin of Life • Many complex organic molecules must have formed before an organism produced • The process of life took many steps over the first 600 my • Probability theory would dictate that at least one random event would have produced a result • This process cannot occur on Earth today because the simple organism would be destroyed by oxidation or predation

  10. Steps in the Origin of Life • Aerobic vs. Anaerobic • oxygen poisons living cells so early life was anaerobic • Lack of free Oxygen >> No Ozone layer • UV radiation kills cells so life had to originate at depth • Water depths of 10m or more • Models • non-oxidizing secondary atmosphere rich in the constituent chemicals for life--H2O, CO2, N • Energy in the form of UV radiation & Hot springs

  11. Steps in Origin of Life • Before the first cell>>Chemical Evolution • production of significant molecules necessary for life • Phosphoric acid crucial to cell chemistry>> phosphoric acid can bond molecules and promote long chain molecule formation • Amino acids formed first since they do not form if oxygen present • probably formed on clay surfaces since they are attractive and absorptive, also protection from UV • Larger Molecules • amino acids are linked together by dehydration synthesis (water loss), clays have potential to absorb water, thus amino acids could be linked on clay surfaces

  12. Experimental Studies • A. I. Oparin- 1930s • Produced sugars and fatty acids from the constituents of an early atmosphere • Urey and Miller- 1953 • Production of cyanide, formaldehyde and 4 different amino acids from water vapor, methane, hydrogen and ammonia and electrical sparks • Subsequent Experiments • Production of 18 of the 20 known amino acids and extremely simple forms of DNA from gases rich in water vapor, CO2, and nitrogen and UV radiation • S.W. Fox (1959) produced protein-like (protenoids) chains from a mixture of 18 amino acids at 70oC in the presence of phosphoric acid

  13. The Environment for Life • Volcanic Hot Springs • Oceanic hydrothermal vent system • Deep (below the level of UV penetration) • Clays and/or Zeolites as templates • Similarity with present day chemosynthetic heterotrophic organisms

  14. Autobiogenesis Spontaneous Origin of Life Oparin, Haldane, 1930’s

  15. Biology G.B.Johnson and R.H.Raven, 1996 • Biology • Biggs et. al. • Glencoe Pub. 2004. • Chap 14.2

  16. Heat Sunlight Electricalenergy Proteins and nucleic acids Simple Cells Biochemistry D. Voet & J.G. Voet Wiley 2004

  17. Molecules of aspartic acid with a left-handed orientation, shown in crystal form, could be the "ancestral Eve" of all amino acids -- the building blocks of proteins -- in life on Earth. The Origin of Life and the Crystallization of Aspartic Acid in Water Tu Lee* and Yu Kun Lin Department of Chemical and Materials Engineering, National Central University, Taiwan, R.O.C. Cryst. Growth & Design 2010

  18. “The landing site of the Mars rover Curiosity was once covered with fast-moving and possibly waist-high water that could have possibly supported life, NASA scientists announced Thursday.” Star Tribune Sept 28, 2012

  19. Autobiogenesis: Spontaneous Origin of Life Oparin, Haldane, 1930’s

  20. Haldane, J. B. S. (John Burdon Sanderson) (1892–1964)known as Jack (but who used 'J.B.S.' in his printed works), was a British-born geneticist and evolutionary biologist. A staunch Marxist, he was critical of Britain's role in the Suez Crisis, and chose to leave Oxford, move to India and become an Indian citizen. He was one of the founders (along with Ronald Fisher and Sewall Wright) of population genetics. Alexander Oparin (1894-1980) The influence of the Marxist theoretical concept of dialectical materialism, part of the Communist Party's official interpretation of Marxism, fit Oparin's definition of life as 'a flow, an exchange, a dialectical unity'. This notion was enforced by Oparin's association with Lysenko.

  21. Stanley Miller, 1953 Chemistry graduate student at University of Chicago

  22. General formula for amino acids

  23. Table 1-4 Yields from Sparking Mixture of CH4, NH2 , H2O and H2

  24. Autobiogenesis: Spontaneous Origin of Life Research into 1970’s supportive Oparin, Haldane, 1930’s

  25. First photograph ever taken from the surface of Mars. Viking 1 Lander July 20, 1976. Primary objectives of the Viking missions - obtain high-resolution images of the Martian surface, - characterize the atmosphere and surface - search for evidence of life on Mars. http://grin.hq.nasa.gov/ABSTRACTS/GPN-2003-00061.html

  26. “…recent advances…have thrown serious doubts on the anoxic [oxygen free] model…” —H. Clemmey and N. Badham “Oxygen in the precambrian atmosphere: An evaluation of the geological evidence.” Geology 10(3), 145 (March 1982). “No geological or geochemical evidence collected in the last 30 years favors a strongly reducing primitive atmosphere…Only the success of the laboratory experiments recommends it.” —R.A. Kerr “Origin of life: new ingredients suggested.” Science 210(4465), 42 (October 3, 1980).

  27. Autobiogenesis: Spontaneous Origin of Life Oparin, Haldane, 1930’s

  28. Can Random Reactions Produce a Protein? Typical protein N = 100-300 How many ways to arrange 100 amino acids, 5 of each type? W= # arrangements = 10115 different peptides <105 useful for life

  29. (1041)(1014 rearrange/s)(1017s) = 1072 polypeptides age of Earth? fastest chemical reaction Can Random Reactions Produce a Protein? How long will it take to create a particular polypeptide? vs. 10115 possible structures

  30. Maillard Reactions Degrade Proteins

  31. Oparin, Haldane, 1930’s

  32. The Enigma of the Origin of Life “The largest stumbling block in bridging the gap between nonliving and living still remains. All living cells are controlled by information stored in DNA, which is transcribed in RNA and then made into protein. This is a very complicated system, and each of these three molecules requires the other two--either to put it together or to help it work. DNA, for example, carries information but cannot put that information to use, or even copy itself without the help of RNA and protein.” Kenneth R. Miller and Joseph Levine, Biology: The Living Science (Upper Saddle River, New Jersey: Prentice Hall), 1998, p.406-407.

  33. The First Cells • All cells use the same genetic code • Archaeobacteria- most primitive • Heterotrophs: obtain energy from surroundings by some chemical reaction • Obtain energy by converting CO2 and H2 to CH4 or by the reduction of sulfur compounds • Eubacteria • 10 Phyla, including cyanobacteria (Autotrophs: manufacture their own food source) • First Cells poorly developed metabolic systems • absorbed nutrients directly • fermentation

  34. Life • Prokaryota • Appear 3.8-3.6 by • no nucleus • single loop chromosome with all genes • reproduction-binary fission • Eukaryota • Single cell appear 2 by • Multicellular appear as trace fossils 1by and as body fossils 700my • Nucleus with 2 pairs of chromosomes (2 copies of all genes) • Asexual and SEXUAL reproduction>> more combinations

  35. Did life arise on another planet? Theory of Panspermia – Hoyle and Wickramasinghe 1980’s

  36. Stanley Miller: the chemical origin of life is a lot more difficult than we first imaged Father of 'Origin of Life’Chemistry Dies May 21, 2007 National Geographic 1998

  37. Antony Flew, a British philosophy professor and leading champion of atheism for more than half a century, changed his mind and became a deist at the age of 81. • He said it was a result of “my growing empathy with the insight of Einstein and other noted scientists” • In an interview with ABC News Flew indicated that a "super-intelligence is the only good explanation for the origin of life and the complexity of nature."

  38. Did life begin by chance or by design? • Huge amount of information in the molecules of life • No naturalistic theory for origin of life • We know that intelligence can create molecules of life • Design is not an argument from ignorance • Is a “super intelligence the only good explanation for the origin of life (A. Flew)” ?

  39. The world looks more complex to a scientist. The world looks more beautiful to a scientist. Science teaches humility. This comes from an understanding of what we do not know. Belief in a Creator has energized the greatest scientists.

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