Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

3ero 1 historyof life mine

2,984 views

Published on

History of the universe and the currently accepted theories on the origin of life.

Published in: Education
  • Be the first to comment

3ero 1 historyof life mine

  1. 1. History of Life • How did all begin??
  2. 2. What are the theories that explain life? Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College.
  3. 3. 3 D . 1 . 1
  4. 4. Big Bang • 13,600 years ago • Galaxies are moving away from us • Black hole areas of intense gravitational pressure particles collide rise in temperature quarks Protons neutrons electronsatoms H He (hellium) Temperature fell Matter concentrated temperature cooled down
  5. 5. WHAT DO YOU THINK EARLY EARTH WAS LIKE? • HOW OLD? • 4.5 BILLION YEARS • BIG BANG - GRAVITY CAUSES DUST PARTICLES TO CONDENSE • METEORS FOR MILLIONS OF YEARS - HOW HOT WOULD THE EARTH BE? • EARTH HAS TO COOL DOWN - STEAM ESCAPES AND RAIN ALLOWS COLLECTION OF WATER - EARTH NOW HAS…… • ATMOSPHERE OF AMMONIA, METHANE, WATER VAPOR, CO2, AND NITROGEN • WHAT IS MISSING? No O2 Too reactive 1st organic molecules didn’t oxidize
  6. 6. • The energy for forming the organic molecules was provided by: – frequent thunder storms and lightning strikes – volcanic activity – meteorite bombardment – high temperatures due to greenhouse gases – UV radiation (no ozone so was extreme) The organic molecules may have been generated on Earth or introduced from space????
  7. 7. HOW WERE THE FIRST CELLS MADE? • DOES ANYONE KNOW FOR SURE? • SPONATEOUS GENERATION VS BIOGENESIS Tales of Miletus/Aristotle 4 elements • FRANCESCO REDI • LOUIS PASTEUR’S EXPERIMENT
  8. 8. LOUIS PASTEUR Pasteur filled a flask with medium, heated it to kill all life,and then drew out the neck of the flask into a long S. This prevented microorganisms in the air from entering the flask, yet allowed air to flow freely. If the swan neck was broken, microbes could enter the flask and grow.
  9. 9. Biogenesis Earth’s atmosphere was ‘reducing’ in the early days. It did not contain oxygen gas until after plants started photosynthesising The atmosphere contained: Hydrogen Nitrogen Water vapor Methane Ammonia Hydrogen sulfide The gases came from abundant volcanic activity
  10. 10. Primitive atmosphere + radiation ORGANIC MOLECULES C+H+O= CARBOHYDRATES C+H+O= LIPIDS C+H+O+N+S= AA
  11. 11. • ALEXANDER OPARIN - CREATION OF MACROMOLECULES WITHOUT OXYGEN (BIOGENESIS) • STANLEY MILLER AND HAROLD UREY EXPERIMENT COACERVATES With RIBONUCLEIC ACIDS (multiplication) ORGANIC MOLECULES RAIN  OCEANS LIPIDS +PROTEINS = MEMBRANE
  12. 12. • FIRST BACTERIA AROUND 3.5 BILLION YEARS AGO • SOME ARE CYANOBACTERIA - THESE ARE PHOTOSYNTHETIC BACTERIA • WHAT ARE THESE BACTERIA GOING TO PRODUCE? • ALMOST 10% ABOUT 2.5 BILLION YEARS AGO • WHAT TYPE OF CELLS ARE BACTERIA? • WHAT TYPE OF CELLS ARE ALL OTHER ORGANISMS? • WHERE DID EUKARYOTIC CELLS COME FROM? • ENDOSYMBIOSIS ONE CELL ORGANISMS NOW! Their own food+ O2 PROKARIOTS UNICELLULAR
  13. 13. ENDOSYMBIOSIS BEGINNING OF THE EUKARYOTIC CELLS • EVIDENCE FOR ENDOSYMBIOSIS • DNA
  14. 14. Mammals Flatworms Annelids Insects Coelenterates Fish Birds Reptiles Crustacea Amphibia Single celled organisms Monocots Herbs Shrubs Trees Dicots Flowering plants Conifers Mosses Liverworts Algae Ferns Fungi Multicellular plants Multicellular animals Mollusc
  15. 15. Life introducedfrom outer space!!! Life Sciences-HHMI Outreach. Copyright 2006 President and Fellows of Harvard College. • Panspermia- “seeds everywhere” – Life came from space on comets • Hydrocarbons, amino acids, water(s) and bacteria
  16. 16. Fixism is is the theory that says that life on earth has always been composed by the species we have today. Creationism is a religious form of fixism. A supernatural being created the world the way we see it. FixismvsEvolutionism Binomial nomenclature/ father of modern taxonomy the rules of heredity/ genes
  17. 17. Lamarck’s Theory Fixismvs Evolutionism • First Evolutionist • Acquired traits can be inherited NO!!! • Use and Disuse • Adaptation – Organisms change as their environment changes
  18. 18. Darwin’s Theory • Published “Origin of Species” • Traveled around the world in the Beagle • He proposed that: – Organisms produce more offsprings than the available resources can support – Organisms fight for limited resources like food, territory, and other necessities of life. Only those who survive can produce their own offspring – Variation exists within species. – Natural Selection - The environment selects organisms with beneficial traits
  19. 19. EVOLUTION NATURAL SELECTION ADAPTATION
  20. 20. Gradual change from one form to another through a period of time The environment selects organisms with beneficial traits A form modified to fit a changed environment
  21. 21. Lamarck's theory - The environment induces the organisms to change. - These changes are always positive (perfection drive) - Use and disuse. - Inheritance of acquired characters (ALSO SHARED BY DARWIN!!!) Darwin's theory - Pre-existing variation - Not all the variations are equally adaptative in a given environment. -S truggle to survive: The best adapted survive and leave more offspring:the next generation will be better adapted (survival of the fittest)
  22. 22. Evidence of Evolution • Any preserved part or tissue of an organism that once lived. FOSSIL
  23. 23. Types of Fossils Casts The mold is filled with another material Molds Hard body structures Imprints Feathers and leaves that form impressions on rocks Petrified Fossils When minerals replace the hard parts of organisms
  24. 24. Biochemical Evidences • Indicate that some organisms have similar DNA sequences, which suggest common ancestry DNA
  25. 25. VARIATION ADAPTIVE RADIATION CONVERGENT EVOLUTION HOMOLOGOUS ORGANS ANALOGOUS ORGANS:
  26. 26. OTHER EVIDENCE OF EVOLUTION – EMBRYOS – VESTIGIAL STRUCTURE APPENDIX- COCCYX-PLICA SEMILUNARIS(eye)- MUSCLES OF THE EAR- GOOSE BUMPS-PALMAR GRASP REFLEX
  27. 27. • GEOGRAPHIC ISOLATION • REPRODUCTIVE ISOLATION WHAT IS SPECIATION? A SPECIES is A group of individuals with similar features that can interbreed (exchange genes) and produce a fertile offspring
  28. 28. Who can say we are not relatives??

×