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Published byKelly Curtis Modified over 9 years ago
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE
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HOW DID LIFE ORIGINATE? – SPONTANEOUS GENERATION LIFE ARISING FROM NON-LIVING MATTER LONG BELIEVED AS THE ACCEPTED EXPLANATION OF ORIGINATION OF LIFE EXPERIMENTS EVENTUALLY SHOWED IT TO BE IMPOSSIBLE – ORIGINATION OF LIFE HAD TO BE A STEP-WISE PROCESS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE MILLER AND UREY’S EXPERIMENT – ATTEMPTED TO EXPLAIN/SHOW HOW EARLY EARTH COULD HAVE GIVEN RISE TO ORGANIC COMPOUNDS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE THE FIRST POLYMERS FORMED ON HOT ROCKS OR CLAY – EXPERIMENTS HAVE SHOWN HEAT ENERGY ON HOT SURFACES PROVIDES SUFFICIENT ACTIVATION ENERGY FOR DEHYDRATION SYNTHESIS REACTIONS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE THE FIRST GENETIC MATERIAL WAS PROBABLY RNA – WHY? – RIBOZYMES RNA THAT ACTED AS ENZYMES
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE MOLECULAR COOPERATIVES ENCLOSED BY MEMBRANES PROBABLY PRECEDED THE FIRST REAL CELLS – EXPERIMENTS HAVE SHOWN THAT IN AQUEOUS ENVIRONMENTS, CERTAIN KINDS OF MOLECULES, INCLUDING LIPIDS AND POLYPEPTIDES, CAN SELF- ASSEMBLE INTO MICROSCOPIC SPHERES FILLED WITH FLUID
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROKARYOTES WERE PROBABLY THE FIRST FORMS OF LIFE BECAUSE… – SIMPLEST FORM OF LIFE (UNICELLULAR PROKARYOTE) – HAVE INHABITED EARTH FOR BILLIONS OF YEARS – IMMENSE NUMBER OF PROKARYOTES EXIST
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE TWO MAIN FORMS OF PROKARYOTES – ARCHAEA VS. BACTERIA (EUBACTERIA) – EXTREMELY DIFFERENT FORMS OF BACTERIA – GENETIC DATA SUPPORTS 3 DOMAIN SYSTEM – BACTERIAL CELL WALLS CONTAIN PEPTIDOGLYCAN; NOT FOUND IN ARCHAEA – BACTERIAS COME IN A VARIETY OF SHAPES/STRUCTURES
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE BACTERIAS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROKARYOTES OBTAIN NOURISHMENT IN A VARIETY OF WAYS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROKARYOTIC NOURISHMENT – “HETEROTROPH HYPOTHESIS” VS CHEMOAUTOTROPHIC HYPOTHESIS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE ARCHAEA CAME FIRST BECAUSE – THRIVE IN EXTREME ENVIRONMENTS AND THE OCEAN EXTREME HALOPHILES SALT LOVERS EXTREME THERMOPHILES HEAT LOVERS METHANOGENS LIVE IN ANAEROBIC ENVIRONMENTS AND GIVE OFF METHANE AS A WASTE PRODUCT – JUST BECAUSE THEY CAME FIRST, DOESN’T MEAN THEY ARE SO OLD THEY ARE EXTINCT!! (ANCIENT DOES NOT EQUAL EXTINCT)
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE DIVERSE STRUCTURAL FEATURES HELP PROKARYOTES THRIVE ALMOST ANYWHERE – PROKARYOTIC FLAGELLUM
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE DIVERSE STRUCTURAL FEATURES HELP PROKARYOTES THRIVE ALMOST EVERYWHERE – PILI TINY APPENDAGES THAT HELP BACTERIA ATTACH TO EACH OTHER AND SURFACES – ENDOSPORES SPECIALIZED “INNER CELL” THAT CAN SURVIVE HARSH CONDITIONS, MAY REMAIN DORMANT FOR CENTURIES
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE CYANOBACTERIA (A.K.A. BLUE-GREEN ALGAE) – SPECIFIC TYPE OF BACTERIAL CELL THAT CAN PERFORM PHOTOSYNTHESIS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE SOME BACTERIA CAUSE DISEASE – PATHOGENS DISEASE-CAUSING AGENTS – EXOTOXINS TOXIC PROTEINS SECRETED BY BACTERIAL CELLS – ENDOTOXINS COMPOUNDS OF THE CELL WALLS OF CERTAIN BACTERIA SANITATION, ANTIBIOTICS, EDUCATION ARE WAYS TO DEFEND AGAINST BACTERIAL DISEASE
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE DISEASE CAUSING BACTERIA
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE BACTERIA CAN BE USED AS BIOLOGICAL WEAPONS **PATHOGENIC PROKARYOTES ARE IN THE MINORITY, MOST PROKARYOTES ARE VITAL TO OUR WELL BEING – EXAMPLES: NITRIFYING BACTERIA, DECOMPOSERS, ETC…
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE THE EUKARYOTIC CELL PROBABLY ORIGINATED AS A COMMUNITY OF PROKARYOTES – MEMBRANE INFOLDING THE ORGANELLES (NOT MITOCHONDRIA AND CHLOROPLAST) ARISE FROM THE INWARD FOLDS OF THE PLASMA MEMBRANE OF A PROKARYOTIC CELL
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE THE EUKARYOTIC CELL PROBABLY ORIGINATED AS A COMMUNITY OF PROKARYOTES – ENDOSYMBIOSIS ONE SPECIES LIVING WITHIN ANOTHER – EXAMPLES??
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROTISTS – A DIVERSE GROUP OF MOSTLY UNICELLULAR EUKARYOTES; SOME PROTISTS ARE PHOTOSYNTHETIC, OTHERS ARE HETEROTROPHIC
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE
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TWO GENERIC TYPES ANIMAL-LIKE PROTISTS A.K.A. PROTOZOA PROTISTS THAT LIVE PRIMARILY BY INGESTING FOOD, A HETEROTROPHIC MODE OF NUTRITION THAT IS “ANIMAL-LIKE” OF PROTISTS PLANT-LIKE PROTISTS A.K.A. ALGAE PROTISTS THAT LIVE BY SYNTHESIZING FOOD FROM CARBON DIOXIDE AND WATER, AN AUTOTROPHIC MODE OF NUTRITION THAT IS “PLANT-LIKE”
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE GROUPS OF PROTISTS – FLAGELLATES – PSEUDOPODIA – CILIATES
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PHOTOSYNTHETIC PROTISTS ARE CALLED ALGAE – ALGAE DEF?? – DINOFLAGELLATES – DIATOMS DIATOMS – GREEN ALGAE PROBABLY MOST INTERESTING EVOLUTIONARILY, BECAUSE IT IS PROBABLY THE ANCESTOR OF LAND PLANTS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE SEAWEEDS ARE MULTICELLULAR MARINE ALGAE – THREE TYPES OF SEAWEED BROWN ALGAE – EXAMPLE: KELP CAN GROW ABOUT 100 METERS) RED ALGAE – SEE PICTURE TO RIGHT GREEN ALGAE
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE MULTICELLULAR LIFE MAY HAVE EVOLVED FROM COLONIAL PROTISTS
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THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE SO THE SIMPLE LIFE CAME FIRST…BUT WHAT CAME NEXT?? THAT’S WHAT NEXT CHAPTER IS ALL ABOUT
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