Evolution & Self-Organization :

1. Evolution & Self-Organization: Oparin’s View Alexander I. Oparin 1894-1980

2. Division of Talk Part 1. Background & Theory Part 2. Model and Experiments Part 3. Criticism & Evaluation

3. What is Life? Metabolism Replication (Dyson, 1985)

4. Life =Replication + Metabolism What was the order in the emergence of the two parts? Was there a single origin of life or did the two parts emerged separately?

5. Double-Origin?But how did they merge? Margulis (1981):“Parasitism and symbiosis as the driving force of cellular complexity” Example: the mitochondria.

6. Three major theories (in chronological order) 1. Oparin (“metabolism”) 2. Eigen (“RNA”) 3. Cairns-Smith (“clay minerals”)

7. Oparin: Overview • First major theory, published in 1924 • Emphasizes the Origin of Metabolism • Primordial “warm soup” in reducing (no oxygen) atmosphere

8. Oparin: Overview (2) The Oparin way:“cells”(coaservates) enzymes genes • Droplets of prebiotic matter (coaservates) • Open Systems • Chemical Evolution: better and better droplets - organization in time and space, growth and reproduction.

9. Eigen: Overview Chemical Evolution Biological Evolution First Cell The Eigen way:RNA enzymes cells Emphasizes the Origin of Replication

10. Cairns-Smith: Overview • Microscopic crystals of minerals in clay where the original genetic material • Surface layer govern the growth of further layers, which can later split. Hence, replication • Organic materials start as “helper” (mechanical support, help in catching ions) and “take over” in a later stage.

11. sketch of the medium:

12. Cairns-Smith: sketch of replication

13. Cairns-Smith: Support • Ferris, 1998: RNA (20-50 mers) Minerals A, U, G, C • A Double-Origin theory • The “simple-start” argument

14. Cairns-Smith: root to life clay enzymes “cells” genes The Cairns-Smith way: 1. Clay minerals 2. organic “helpers” 3. organic take-over

15. Theories of the Origin of Life

16. The Origin of Origin-of-Life Theory 1953,Watson & Crick 2000,Weizmann Inst., OOL course 1859, Darwin 1924, Oparin 1981, Eigen 1953, Miller 1981, Cairns-Smith

17. Before Oparin: early theories • Spontaneous Generation • First scientific attempts: ( Redi - 1668,Pasteur - 1860 )

18. Oparin: ideological background • Stalin, Lysenko (Lepeshiskaya) • Idealism Vs. Materialism

19. Oparin: summery of terms COASERVATE REDUCING ATMOSPHERE CHEMICAL EVOLUTION OPEN SYSTEM

20. Autotrophy A B C D A A B B C C D D Hetrotrophy … and two more HETROTROPHY Vs. AUTOTROPHY

21. Oparin’s contributions ( Stanley et al., 1997 ) • The proposal of a reducing atmosphere for the prebiotic synthesis • The proposal that anaerobic fermentation was primordial • The idea of a transition from hetrotrophy to autotrophy

22. Oparin’s Model of Evolution

23. Coacervate:Insoluble complexes of macromolecules Probionts:Assembly of polymers created by abiogenic synthesis Probionts are open systems

24. 1- Chemical evolution Quantum mechanics Thermodynamis Kinetics 2- Prebiological evolution Entropy Adaptation Heredity Two major stages in the process of evolution “Natural selection”

25. To Hetrogeneous solutions- Interaction of macromolecules As a result Interaction with the environment Natural selection Individual structures According to Oparin Formation of phase-separated systems Homogeneous solutions of “HMW” compounds

26. Differentiation of coacervate drops Histone Gum arabic ADP Mg2+ Toluidine blue Histone Gum arabic ADP Mg2+ Toluidine blue Catalyst ADP Polyadenylic acid

27. Division Self assembly of new daughter structures Complete separation and disjunction Growth of prebiological structures

28. Probionts division Polyphosphate Protamin- poly A Polylysin Histone- gum arabic

29. N- drop concentration (ml) V-mean drop volume

30. Shown by DNA complexes with basic polypeptides Specific interaction “HMW” DNA and histone Yields Insoluble filamentous complex Polymerization process

31. Denaturated DNA+ histone Ultrasonically treated DNA+ histone DNA+ histone

32. Relationship between the structure of nucleoprotein and polynucleotides

33. (A)+(U)+ polylysine RNAase Polyadenylic acid Polyuridilic acid

34. Starting point Increase in the length of polynucleotides Single-stranded molecules of poly(A)-poly(U) complex are responsible for the formation of double stranded polynucleotide strands.

35. Organisms Biopolymers Biological Prebiological selection Probionts Polymers with the higher degree of organization Prebiological selection Prebiological Primitive Probionts Oligo/polymers with low degree of organization Non-specific self assembly Free olygomers and polymers Chemical

36. Oparin’s Theory:Criticism & Evaluation ... the existence of life must be considered as an elementary fact that cannot be explained, but must be taken as a starting point in biology, in a similar way as the quantum of action, which appears as an irrational element from the point of view of classical mechanical physics, ..., forms the foundation of atomic physics. N. Bohr

37. Criticism & Resistance • Theological. • Ideological and Personal. • Scientific.

38. Theological Conflict • As the first modern theory of life creation • As the theory that established major concepts (like prebiotic soup) The theory met tough theological resistance

39. Ideological & Personal criticism The theory was devised in USSR, vulnerable to influence of: • Politicized science(mobilizing all means to prove the ideology), • Limitation of scientific freedom(genetics was outlaw), • Oparin's association with Lysenko.

40. Lysenko "theory" • Evolution of specimens in their lifetime. Environmental Adoptation

41. Credibility of Oparin • Survival vs. belief? • Ideology vs. scientific thought? • Non-standard point of view? Fact: the theory survived decades of scientific debate & discovery,adapting to them,without changing its basics.

42. Scientific Debate 1. The role of enzymes in the theory. 2. Optical asymmetry explanation. 3. Environmental assumptions. 4. Miller experiment applicability. 5. Carbon isotope evidence. 6. Probabilistic view.

43. Scientific toolsto evaluate the theory Geochemistry- Conditions on the primitive earth. Physics- Evolution of non-equilibrium open system Chemistry- “Probionts” Biochemistry- Prebiological evolution Paleontology- Prebiological microfossils

44. Using enzymes as part of theory presentation. • Sydney Fox proteinoids: • Ball like protein structure. • Created by heating Amino Acids in dry environment. • No complex Catalysts required. • Functionally similar to coacervates. • Oparin's theory is a theoretical one.It doesn't give complete explanation of every step.

45. Optical Asymmetry • All Life-Supporting Sugars are L-type. • Life Participating Proteins are predominantly D-type.

46. Optical asymmetry explanation Criticism: • No explicit explanation of asymmetry. Justification: • Obvious explanation of asymmetry under assumptions: • Sufficiency of D-type sugars. • Asymmetric system is more simple. • Chemical natural selection.

47. Environmental assumption Assumed: • Reducing atmosphere. • No free oxygen. • Ammonia in the atmosphere. Current Knowledge: • Neutral atmosphere. • Presence of oxygen. • Ammonia - dissolved in ocean.

48. Miller experiment applicability Criticism: • Adenine & amino sequences weregenerated only with human interference. • Phospholipids, DNA, RNA were not generated. • Primeval atmosphere content is questionable. • Justification: • It illustrates a possibility, not necessity for Oparin's theory.

49. Carbon Isotope Evidence • Expected:low level of Carbon-13 in ~4*109 years sediments. • But:evidence of high level of Carbon-13. Reason for interest:Carbon-13 known to be created by photosynthesis.

50. Probabilistic view Statistical evaluation (by a skeptic) shows: • molecule: iso-1-cytochrome c. • length: 110 amino acids. • Probability to find among random proteins: 2*10-44 • for 1M trials per second in every cubic meter: 100,000,000,000,000 years !!