RFHendrix said:
Hi everyone.
I did not see a discussion on origins on this board so I thought I would start one. Here is an excerpt from my new book about the idea that DNA or RNA in a supposed "world" could somehow self-organize it self into meaningful coded communication that must exiist before life can come into being.
From the chapter;
The Foundation of All Life is the Written Word:
...Lets say there is a pile of plastic letters lying around outside. The wind blows these millions of letters around for millions of years and eventually we come on the scene and look the situation over.
I hope this book isn't published yet. If so, you embarrassed yourself by failing to do research in three areas:
1. Ribozymes.
2. Thermal proteins and protocells.
3. Origin of the genetic code.
Information arises from chemistry and does so because different molecules are not identical. RNA can also act as an enzyme, catalyzing reactions necessary for life. The smallest ribozyme is
three nucleotides long. Not hard to assemble by simple chemical reactions. Now, from the hydrogen bonding of nucleotides (used to make double stranded DNA) RNA can also serve as a template for it's own replication. Some relevant references are:
7. P S Chimmel and R Alexander, All you need is RNA. Science 281:658-659, Jul. 31, 1998. Describes research showing that RNA in ribosomes sufficient to make proteins. Intermediate step in going from abiogenesis to genetic code.
20. RJ Davenport, Making copies in the RNA world. Science 292: 1278, May 18, 2001. Used in vitro evolution to make ribozyme that can faithfully copy other RNA molecules up to 14 nucleotides long. Uses any RNA as sequence as template. Ribozyme itself is 189 nucleotides long. 98.5% accurate (99.9% for RNA polymerase). Screened 10^15 ribozymes. Primary paper is WK Johnston, PJ Unrau, MS Lawrence, ME Glasner, DP Bartel, RNA-catalyzed RNA polymerization: accurate and general RNA-templated primer extension. Science 292: 1319-1326, May 18, 2001.
3: J Theor Biol 2000 Jan 21;202(2):129-44
Physico-chemical constraints connected with the coding properties of the genetic system.
Nat Struct Biol 2000 Jan;7(1):28-33 Ribozyme-catalyzed tRNA aminoacylation. Lee N, Bessho Y, Wei K, Szostak JW, Suga H
Now, proteins also contain information. That is because amino acids are not identical chemically, so not every possible sequence of amino acids is possible. There is chemical selection. For instance, using just 3 differnt amino acids, you should get 27 different tripeptides. However, when you form these tripeptides by thermal heating (chemistry), you only get 6.
Some references for you in this field are:
http://www.siu.edu/~protocell/
http://www.theharbinger.org/articles/rel_sci/fox.html
Tyagi S, Ponnamperuma C Nonrandomness in prebiotic peptide synthesis. J Mol Evol 1990 May;30(5):391-9
SW Fox, Self-sequencing of amino acids and origins of polyfunctional protocells. Origins of Life, 14: 485-488, 1984.Nakashima, T, Jungck, JR, Fox, SW, Lederer, E, Das, BC. A test for randomness in peptides isolated from a thermal polyamino acid. Intl. J. Quantum Chem. QBS4: 65-72, 1977.
Luque-Romero MM, de Medina LS, Blanco JM. Fractionation and amino acid composition of an aspartic acid-containing thermal proteinoid population. Biosystems. 1986;19(4):267-72.
Bahn, P. and A. Pappelis. 2001. HPLC evidence of nonrandomness in thermal proteins. In First Steps in the Origin of Life in the Universe. Julián Chela-Flores, Tobias Owen, and François Raulin, eds., Kluwer Academic Publishers, Dordrecht, The Netherlands. Pp. 69-72.
As to the third, origin of the genetic code and directed protein synthesis, it can come from either protein first scenarios or RNA first scenarios. Again from chemical constraints. Some relevant references are:
Nakashima T, Fox SW. Selective condensation of aminoacyl adenylates by nucleoproteinoidmicroparticles (prebiotic-lysine-model system-genetic code).Proc Natl Acad Sci U S A. 1972 Jan;69(1):106-8.
Yuki A, Fox SW. Selective formation of particles by binding of pyrimidine polyribonucleotides orpurine polyribonucleotides with lysine-rich or arginine-rich proteinoids.Biochem Biophys Res Commun. 1969 Aug 15;36(4):656-63.
9. AM Poole, DC Jeffares, D Penney, The path from the RNA world. J. Molecular Evolution 46: 1-17, 1998. Describes Darwinian step-by-step for evolution from RNA molecules to cells with directed protein synthesis. All intermediate steps are useful.
Good luck on revising your book before it's too late.