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Water and Life

Water and Life. Setting the stage for the evolution of advanced forms of life. Radius of the earth:. Circumference of the earth:. Total water on earth:. % readily available fresh water:. Age of the earth:. Water’s appearance on the earth:. 3 sources of earth’s water:.

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Water and Life

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  1. Water and Life

  2. Setting the stage for the evolution of advanced forms of life Radius of the earth: Circumference of the earth: Total water on earth: % readily available fresh water: Age of the earth: Water’s appearance on the earth: 3 sources of earth’s water: Water is an essential precursor to life.

  3. Water and Life The most abundant substance in living systems % 70 New born baby    ~ 77% Grown-up man     ~ 65% Grown-up woman ~ 58% The elderly            ~ 50% Human body = 65% Plants = 80% Fruits and Vegetables = 70-80%

  4. Water and Life Waterisan ideal medium for biochemical reactions: 1. retains heat, moderates temperature 2. excellent solvent 3. transports nutrients, life compounds 4. Participates in reactions

  5. 22% 73% 79% Heart 77% Lungs 80% Kidneys 80% Brain 85% same salinity as the ocean

  6. Average person has about 50 quarts of body water A loss of just 5 percent of the body's total water will cause the mouth to go dry, the surface of the skin to shrink, and may even cause hallucinations A loss of more than 12 - 15 percent total body fluid would be fatal. The longest anyone has ever survived without water is _____ 15 percent of human water loss is through the act of respiration 20 percent is lost through perspiration 65 percent is lost by excretion

  7. Water and Life’s Beginnings

  8. Commonality in all living things: • Organisms consist of similar • organic (carbon-rich) compounds. Human body is 18% carbon • Proteins found in present-day • organisms are fashioned from • one set of 20 standard amino acids proteins are essential to development, growth, and reproduction RNA Catalysis Metabolism growth DNAAmino AcidsProteins Catalysis

  9. Proteins Protein Synthesis To make a protein, the combination of amino acids requires reaction with water.

  10. Water and Life The Miller Experiment 14 of the 20 natural amino acids appear Atmosphere Ocean

  11. Water as a Precursor to Life Water is necessary for protein synthesis from AAs Proteins are necessary for synthesis of DNA/RNA DNA/RNA carry genetic information necessary for life

  12. It all starts with water 3.35 – 3.5 bya ~ 4.4 bya

  13. First Organisms Anaerobic: live in oxygen – free environments Autotrophic: produce complex organic compounds from simple inorganic molecules and an external source of energy. Organic compounds: glucose Inorganic molecules: CO2 Energy source: light or chemical reactions (sulfide, iron) Light: photoautotroph chemicals: chemoautotroph

  14. Earliest Organisms chemoautotrophic Embedded in the lava are numerous tubular structures left behind by ancient microbes ~ 3.5 bya tubes contain carbon that represents organic material left behind by the early organisms.

  15. Cyanobacteria (Blue-green algae) 3.0 – 3.5 bya bacterial fossils 3.5 bya Photosynthetic Fix atmospheric carbon dioxide into complex organic compounds. light CO2 + H2O C6H12O6 + O2 (Simplified) - removed carbon dioxide - added oxygen to the atmosphere

  16. Stromatolites the oldest macroscopic evidence of life on Earth, at least 2.5 billion years old Calcium Carbonate Cyanobacteria colonies Colonies of Cyanobacteria Produced billions of tons of oxygen

  17. Dissolved Iron in oceans

  18. Approximately 2.0 bya light CO2 + H2O C6H12O6 + O2 In oceans 2 Fe II + 3O2 Fe2O3 ferrous ferric Banded Iron Formations

  19. Approximately 1.5 bya light CO2 + H2O C6H12O6 + O2 2 Fe II + 3O2 Fe2O3

  20. Oxygen in the Atmosphere/Oceans coincides emergence of complex cells and multi-cellular organisms Oceanic

  21. ~ 400 million years Higher Oxygen Levels Ozone Layer Terrestrial Life

  22. Carboniferous Period About 350 million years ago “the age of swamps and coal"

  23. 245 mya – 65 mya Age of Reptiles Warm Wet Productive

  24. Subsequent Timeline Mammals ~65 million years ago Primates ~30 million years ago Pre-humans ~5 million years ago Homo sapiens ~200,000 years ago

  25. Liquid water 3.5 – 4.4 bya Earliest organisms 3.5 bya Cyanobacteria 3.0 – 3.5 bya Stromolites 2.5 bya Iron Formations 2.0 bya Atmospheric O2 increase 1.5 bya Complex/multicells 1.0 bya Ozone Layer 400 mya Carboniferous 350 mya Reptiles 245 mya Mammals 65 mya

  26. Next: Water and the Fossil Record

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