CREATION NARRATIVE – The Creation of Life THE SECOND GENESIS: CREATION OF LIFE ITSELF Bacterial Life arose on earth at the earliest possible time. As soon as the Earth had cooled and stabilized - 3.9 to 4.0 BY ago. Evidence: C-13/C-12 ratio in old rocks. Even the "simplest" life is vastly complex. 20 CREATION NARRATIVE – The Creation of Life 2 THE COMPLEXITY OF LIFE 1998 NAS Conference: Size Limits of Very Small Microorganisms*. Response to NASA’s “Mars Fossils” Minimum size: DNA over 200,000 bp Minimum volume: 1000x Mars “Fossils” David C. Bossard Chapter 6 21 CREATION NARRATIVE – The Creation of Life 3 THE COMPLEXITY OF LIFE Must have machinery to process its genetic information Called the CENTRAL DOGMA – every cell does it! [See the handout reproduced on the next slides] 22 CREATION NARRATIVE – The Creation of Life (Handout) THE CENTRAL DOGMA - 1 • DNA. The genetic information is recorded in long ladder-like molecules of DNA. Each rung of the ladder (a base pair) is a pair of 4 short molecules called nucleotides A,T,C and G. They always pair in the same way: A (adenine) pairs with T (thymine), and C (cytosine) pairs with G (guanine). The sides of the ladder are sugar molecules strung end-on-end. The size of the DNA is expressed in the number of base pairs. A Codon is a triplet of base pairs. Each codon corresponds to one of twenty Amino acids -- it’s the amino acids that are the building-blocks of proteins, which do the work of the cell. 23 CREATION NARRATIVE – The Creation of Life (Handout) THE CENTRAL DOGMA - 1 Translation. To every codon there is a special molecule called tRNA that has that codon on one end and has its associated amino acid attached to the opposite end. A given codon (virtually) always associates with the same amino acid -- across all species. Generally a cell must have at least 30 different tRNA molecules to make its proteins; each tRNA must have the genes to build itself as part of the cell's DNA. Some genes code for RNA molecules -- such as tRNA -rather than proteins. There are many RNA molecules used in regulation. A gene is a sequence of codons. Each gene corresponds to a particular protein that is used by the cell to do its work. 24 CREATION NARRATIVE – The Creation of Life (Handout) THE CENTRAL DOGMA - 2 • Regulatory Molecules. Hanging around the cell's DNA are a number of molecules -RNA polymerases, repressors and other regulatory molecules that determine if, when and how often a given gene will be copied to make proteins. These molecules are part of a complex regulatory system that is an essential for reading the DNA. Without this regulatory apparatus -- which may be as complex as the DNA itself -- the DNA is useless. Regulatory Molecules around DNA 25 CREATION NARRATIVE – The Creation of Life (Handout) THE CENTRAL DOGMA - 3 • Messenger RNA. When a given gene is to be copied, the rungs of the DNA ladder split and the left-half is copied into a messenger molecule called mRNA. After error checking and correcting, this mRNA moves away from the DNA and out of the nucleus to the main part of the cell to begin making proteins. 26 CREATION NARRATIVE – The Creation of Life (Handout) THE CENTRAL DOGMA - 4 • Ribosomes. Complex motor molecules called ribosomes surround the mRNA chain and begin to transcribe the codons and build an amino acid chain that will be the future protein. This is done by matching a tRNA molecule to a codon, and then detaching the amino acid and adding it to the building chain. Every living species from the simplest to the most complex requires these complex ribosome motors to carry out gene processing. 27 CREATION NARRATIVE – The Creation of Life (Handout) THE CENTRAL DOGMA - 5 It takes over 50 genes just to form the ribosomes. See the Wikipedia article on ribosome biogenesis. • Folding. Once the protein chain is complete, it then detaches from the ribosome and folds into the shape that it must have to carry out that protein's specific function. Generally this folding uses other helping molecules called chaperones, that guide it to make the correct shape. 28 CREATION NARRATIVE – The Creation of Life 4 THE COMPLEXITY OF LIFE EVERY Living Cell carries out the same “Central Dogma” Around 200 genes are required just to build this complex machinery. 29 TAKE A BREAK 30 CREATION NARRATIVE – The Creation of Life 5 PARADOXES IN THE CREATION OF LIFE The Combinatoric Paradox The Eigen Paradox The Levinthau Paradox The Regulatory Paradox. 31 CREATION NARRATIVE – The Creation of Life 5 PARADOXES IN THE CREATION OF LIFE The Combinatoric Paradox -- Wistar Institute Conference (1966) “Mathematical Challenges to the Neo-Darwinian Interpretation Of Evolution” (Wistar Institute Monogram No. 5, 1967). "It is our contention that if 'random' is given a serious and crucial interpretation from a probabilistic point of view, the randomness postulate is highly implausible …." Murray Eden, Inadequacies of Neo-Darwinian Evolution as a Scientific Theory Wistar Institute Symposium, 1966, p. 109 32 CREATION NARRATIVE – The Creation of Life 5 PARADOXES IN THE CREATION OF LIFE The Combinatoric Paradox -- Wistar Institute Conference (1966) “Mathematical Challenges to the Neo-Darwinian Interpretation Of Evolution” (Wistar Institute Monogram No. 5, 1967). Thus, if natural evolution did occur then the only plausible conclusion is that it occurred as a result of some (to date unknown) natural laws. 33 CREATION NARRATIVE – The Creation of Life 5 PARADOXES IN THE CREATION OF LIFE The Combinatoric Paradox Four Responses: 1. Perhaps Life came here from outer space? 2. Infinity of Universes Argument: Any event, no matter how improbable, will surely occur given enough universes. Reply: Abuse of concept of infinity – It can be used to justify the repeated recurrence of any event, however low the probability. Are there an infinite number of universes with a Dr. David C. Bossard giving lectures on the Creation Narrative? 3. Build big by starting small and combining them. Reply: The Fallacy of Betting Systems – "there is no combination or betting system that will turn the odds into your favour." The odds of getting a very low probability result cannot be helped by any “system”. 34 CREATION NARRATIVE – The Creation of Life 5 PARADOXES IN THE CREATION OF LIFE The Combinatoric Paradox Four Responses: 4. There Must be Unknown Natural Laws. Reply: Then spend your time finding them, instead of writing books that make the lazy argument that Evolution is Fact not Theory. Note: Promising research is being done in this direction in the new science of Evolutionary Development (EvoDevo for short). However this research is directed to modifying existing gene expression, not to creating genes in the first place. 35 CREATION NARRATIVE – The Creation of Life 6 PARADOXES IN THE CREATION OF LIFE The Eigen Paradox* A gene with over 100 base pairs must be accompanied by error-correction code (also encoded in genes) that is more complex than the original gene. The implication is that it is impractical to try to “bootstrap” the building of large functional genes by random, undirected processes. 36 CREATION NARRATIVE – The Creation of Life 7 PARADOXES IN THE CREATION OF LIFE The Levinthal Paradox A large protein can fold in countless ways, most of which by necessity have never been tried in the entire life of the universe. There is no obvious biological way to predetermine a particular folding without the help of “chaperone” proteins. So how do proteins (or the life systems) “know” how to fold? 37 CREATION NARRATIVE – The Creation of Life 8 INVENTIONS OF THE FIRST LIVING SPECIES* The Central Dogma (already noted) Carbon Fixing RuBisCO Photosynthesis Chlorophyll-II: Energy Storage (ATPase) Chlorophyll-I: Carbon Fixing & Calvin Sugar Cycle Nitrogen Fixing Nitrogenase Heterocysts David C. Bossard Chapter 7 Chapter 6 38 CREATION NARRATIVE – The Creation of Life 8 INVENTIONS OF THE FIRST LIVING SPECIES Carbon Fixing RuBisCO Smaller unit: 123 amino acids Larger unit: 475 amino acids 39 CREATION NARRATIVE – The Creation of Life 8 INVENTIONS OF THE FIRST LIVING SPECIES Photosynthesis Chlorophyll-II (Photosystem II): (P680) Energy Storage (ATPase) "The strongest biological oxidizer known."* Chlorophyll-I (Photosystem I): (P700) Carbon Fixing & Calvin Sugar Cycle "The strongest biological reducer known."* "These are such complex biological processes, that the complexity and early appearance on earth seems to indicate planning and design." PNAS - Nat'l Acad. Sci. (2006)* 40 CREATION NARRATIVE – The Creation of Life 8 INVENTIONS OF THE FIRST LIVING SPECIES The ATP Synthase motor molecule ATP ATP Synthase 41 CREATION NARRATIVE – The Creation of Life 8 INVENTIONS OF THE FIRST LIVING SPECIES Nitrogen Fixing Nitrogenase "unique in the history of life." Heterocysts Cyanobacteria 42