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11/4/2007

Origins of in the Zackary Johnson OCN201 Fall 2007 zij@.edu Zackary Johnson http://www.soest.hawaii.edu/oceanography/zij/education.html Uniiiversity of Hawaii Department of

Class Schedule

Nov‐2Originsof Life and the Universe Nov‐5 Classification of Life Nov‐7 Nov‐9Consumers Nov‐14 : Processes (Steward) Nov‐16 Evolution: (Steward)() Nov‐19 Marine Nov‐21 Benthic Communities Nov‐26 Whale Falls (Smith) Nov‐28 The Marine Web Nov‐30 Dec‐3 Dec‐5Global Ecology Dec‐12 Final

Major Concepts TIMETABLE ! • Life started early, but not at the beginning, of ’s (and other formed) history • is the leading hypothesis to explain the beginning of life on Earth • There are many competing theories as to how this happened • Some of the details have been worked out, but most Formation of Earth have not • Abiogenesis almost certainly occurred in the 20‐15 15‐94.5Today Billions of Before Present

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Building Blocks TIMETABLE Big Bang! • Universe is mostly (H) and (He); for Milky Way (and other galaxies formed) example –the is 70% H, 28% He and 2% all else! Abundance) e • Most of interest to

(C, N, P, O, etc.) were (Relativ 10 produced via nuclear fusion Formation of Earth Log at very high reactions in large after Big Bang 20‐13 13‐94.7Today Atomic Number Billions of Years Before Present

ORIGIN OF LIFE ON EARTH Abiogenesis: 3 stages Divine Creation 1. Origin of biological Spontaneous 2. Origin of biological Generation 3. Evolilution from molllecules to cells

Abiogenesis

Abiogenesis: The primordial Miller‐Urey experiment / Oparin‐Haldane hypothesis Abiogenesis: The Miller‐Urey experiment / Oparin‐Haldane hypothesis • Only produced some of the amino • No RNA or DNA produced (but later experiments did) • Conditions used are not necessarily representative of those of

• Start: H2O, CH4, NH3, H2 + spark • End: Amino acids (13/22), complex

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Abiogenesis: required components • CH4 – • NH3 – • H2O – • H2S –hydrogen • CO2 – dioxide • PO4 – • And no O2 ()

Abiogenesis: 3 stages Abiogenesis: next steps… 1. Origin of biological monomers 1. form bilayers ( 2. Origin of biological polymers membranes) 3. Evolilution from molllecules to cells 2. polymerize into random RNA –some self‐replicate () 3. Selective pressures to 4. outcompete ribozymes

Abiogenesis: alternative hypotheses 1. First – original form of ‘life’ was naked genes (ex. hypothesis, RNA world) 2. First – chemical reactions can synthesize organic molecules (ex. I/SlfIron/ world) 3. Bubble Theory – concentration of organic molecules 4. Others...

EarlyPhotosynthesis,RegardlessLife evolvedlife was of afterprobablythe (especially precise the earthheterotrophic oxygenicmechanism, and ) (used life formed: evolved organics) evolvedlife relatively requires much quickly waterlater

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Major Concepts • Life started early, but not at the beginning, of Earth’s history • Abiogenesis is the leading hypothesis to explain the beginning of life on Earth • There are many competing theories as to how this happened • Some of the details have been worked out, but most have not. • Abiogenesis almost certainly occurred in the ocean

http://www.soest.hawaii.edu/oceanography/zij/education.html

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