THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE

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

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

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

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE THE FIRST GENETIC MATERIAL WAS PROBABLY RNA – WHY? – RIBOZYMES RNA THAT ACTED AS ENZYMES

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

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

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

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE BACTERIAS

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROKARYOTES OBTAIN NOURISHMENT IN A VARIETY OF WAYS

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROKARYOTIC NOURISHMENT – “HETEROTROPH HYPOTHESIS” VS CHEMOAUTOTROPHIC HYPOTHESIS

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)

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE DIVERSE STRUCTURAL FEATURES HELP PROKARYOTES THRIVE ALMOST ANYWHERE – PROKARYOTIC FLAGELLUM

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

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE CYANOBACTERIA (A.K.A. BLUE-GREEN ALGAE) – SPECIFIC TYPE OF BACTERIAL CELL THAT CAN PERFORM PHOTOSYNTHESIS

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

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE DISEASE CAUSING BACTERIA

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…

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

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE THE EUKARYOTIC CELL PROBABLY ORIGINATED AS A COMMUNITY OF PROKARYOTES – ENDOSYMBIOSIS  ONE SPECIES LIVING WITHIN ANOTHER – EXAMPLES??

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE PROTISTS – A DIVERSE GROUP OF MOSTLY UNICELLULAR EUKARYOTES; SOME PROTISTS ARE PHOTOSYNTHETIC, OTHERS ARE HETEROTROPHIC

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE

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”

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE GROUPS OF PROTISTS – FLAGELLATES – PSEUDOPODIA – CILIATES

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

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

THE ORIGIN AND EVOLUTION OF MICROBIAL LIFE MULTICELLULAR LIFE MAY HAVE EVOLVED FROM COLONIAL PROTISTS

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