The History of Earth & Life

1. The History of Earth & Life

2. Spontaneous Generation The idea that living things could arise from nonliving things. T Believers included great mindslike: Aristotle Sir Isaac Newton (384 BC - 322 BC) 1643 - 1727

3. Spontaneous Generation • raw meat gave birth to maggots • rotting logs at the bottom of lakes & rivers gave birth to alligators and crocodiles

4. Spontaneous Generation • mice from dirty hay • Mud gives birth to mudpuppies • Morning dew giving rise to ladybugs

5. Disproving Spontaneous Generation • Francesco Redi (1626-1697) - a scientist who used experiments to disprove spontaneous generation of macro (large) organisms. • Results: Covered flask no maggots Open flask maggots Conclusion: Raw meat does not give rise to maggots. THE MAGGOTS CAME FROM FLIES!!!

6. Disproving Spontaneous Generation • With the discovery of the microscope, scientists found a tiny world teeming with life. • Scientists concluded that microorganisms arise spontaneously from a “Vital Force” in the air. • In definition “Vital Force” states that microorganisms arise spontaneously from the air.

7. Disproving Spontaneous Generation of Microorganisms • Lazzaro Spallanzani (1729-1799) - attempted to disprove spontaneous generation of microorganism. • He stated that microorganisms formed from other micro- organisms, not from air. • Many skeptics still believed in the “Vital Force” & spontaneous generation hung around for another 100 years.

8. Disproving Spontaneous Generation of Microorganisms • By the mid 1800s, the controversy of spontaneous generation had grown fierce. • The Paris Academy of Science offered a prize to anyone who could clear up the issue of spontaneous generation.

9. Disproving Spontaneous Generation of Microorganisms • Louis Pasteur (1822 - 1895) used a curve-necked flask. • This technique allowed air with the so called “Vital Force” to mix with the broth in the flask, but prevented microorganisms from entering the body of the flask.

10. Biogenesis All living things come from other living things!!!

11. History of Earth The solar system formed 5 billion years ago.

12. History of Earth • Earth & other planets formed about 4.6 billion years ago by repeated collisions from space debris. • 2000˚ F - same as the Sun • The surface is a entirely molten

13. Great Impact Theory -1974 • Thea (Mars -sized planet) collides with Earth at 25,000 mph. • Sent billions of tons of debris from Earth’s crusts. • Over 100 years a ring of hot dust & rock circled the Earth, collecting more debris forming the Moon. • 1/50th the size of Earth.

14. Spin Off Theory • The Earth was very hot and spinning rapidly. • Moon split off of it.

15. History of Earth - 3.5 billion years ago • Early volcanic activity formed earth’s atmosphere. • Millions & millions of years of rain filled the oceans, lakes & rivers. • Iron rich oceans - green in color. • Temperature exceeds 200˚ F.

16. History of Earth • Early earth’s atmosphere was very inhospitable. • Very little O2 – (oxygen) • Mostly water vapor • Nitrogen • Methane(carbon based compound) CH4 • Ammonia (inhospitable) NH3 • Hydrogen (H2)

17. History of Earth -2.5 to 1.5 billion years ago • Granite continents rise from the mantle. • Stromatolites - are cyanobacteria found around every continent that produced O2

18. Stromatolites - aka cyanobacteria • The O2 rusted out the iron filled oceans turning all green oceans blue. • All this O2 formed the ozone (O3) layer protecting the Earth from harmful UV rays, allowing multi-cellular organisms.

19. History of Earth -700 million years ago • Snowball Earth - 40˚F • All life gone, except marine bacteria & algae in the oceans under the ice. • The core & volcanic eruptions caused a greenhouse effect & the Earth heated up.

20. History of Earth-225 million years agoPangaea(one land mass) to present day earth.

21. ALFRED WEGENER 1912 The Theory of PLATE TECTONICS or The Theory of CONTINENTAL DRIFT

22. Wegener noticed similarities in organisms from different continents

23. “All in the family” • Ostrich – • Africa ******************* • Emu – • Australia ************** • Rhea – • South America

24. Wegener noticed other similarities • Fossils indicate that the camel family originated in North America – where it became extinct. • Migrated to South America Llamas, alpacas, vicunas • Also migrated to Asia via Siberia. Africa and central Asia.

25. In addition, Wegener noted: • Fossil records show tropical plants in the artic

26. Found Trilobites all over the world. • Particularly common fossil. • Found primarily in rocks from the first half of the Paleozoic era.

27. History of Earth - after Pangaea • as Pangaea broke apart the Earth was battered by many asteroids, volcanic eruptions & ice ages. • 66 million years ago a huge asteroid (as big as Mt. Everest) collided with the Earth, sending debris & dust that totally blocked out the Sun. • the Earth began another ice age • all plant life died, followed by the Dinosaurs & almost all other organisms died. • last ice age occurred 12,000 years ago.

28. Earth - Present day

29. Earth

30. How old is the Earth? • During the mid 1600's, Archbishop James Usher of Ireland, calculated the age of the earth based on the genealogies from Adam and Eve. • According to Usher's calculations, the earth was formed on October 22, 4004 B.C. Making the Earth almost 6,000 years old.

31. How old is the Earth? • Many geological structures and processes cannot be explained if the earth is only 6000 years old.

32. The Grand Canyon was actually formed in 6 million years . • Nearly two billion years of the Earth's geological history have been exposed as the Colorado River and its tributaries cut their channels through layer after layer of rock while the Colorado Plateau was uplifted.

33. The Grand Canyon’s Sky Walk

34. How old is the Earth? • Leonardo da Vinci - painter, architect and engineer. • Calculated the sedimentation rates in the Po River of Italy. • Concluded it took 200,000 years to form some nearby rock deposits.

35. How old is the Earth? • Relative Dating - uses rock layers to date fossils. The lower the object is the older it is. Examples: Grand canyon, Stack of newspapers

36. Relative Dating:The process of putting things in a "correct order”Use #”s 1-7 2 • ___ I got out bread, peanut butter and jelly. • ___ I ate the sandwich. • ___ I put the two pieces of bread together. • ___ I spread a layer of jelly on another piece of bread. • ___ I was hungry. • ___ I spread a layer of peanut butter on a piece bread. 6 5 4 1 3

37. Relative Dating:

38. Radiometric dating • Determines the age of an object by the natural decay of an element. • Radioactive isotope C14 decays to C12 • Isotopes- are the same element, same # of protons, but different # of neutrons.

39. How old is the Earth? • C14 is used to date living or once living things • When organisms dies it contains100% C14 • In one half-life the organism will have 50% C14 & 50% C12 • C14 has a half life of 5730 years C14 - red C12 -blue

40. 50 • Carbon 14 half-life is 5730 years. • In one half-life how much C14 - ______%. How old is the organism? _____ • In two half-lives how much C14 - ______%. How old is the organism? ______ 5730 25 11460

41. How old is the Earth? • C14 dates objects up to 50,000 years old • Isotope potassium 40 has a half-life of 1.3 billion & therefore used to date the earth • potassium 40 decays into argon 40

42. How old is the Earth? Radiometric Dating suggest that the earth is 4.6 billion years old!

43. Life on Earth? • In the 1920s, Alexander Oparin and J. B. S. Haldane proposed an idea for how life may have originated on Earth. • They stated - early atmosphere contained very little O2 ammonia(NH3) H2 gas water vapor & methane(CH4)

44. Life on Earth? • Oparin & Haldane stated that, as the earth cooled these gases condensed & collected in a “primordial soup”. • These elements, triggered by lightning combined to form proteins, the building blocks for life.

45. Life on Earth? • Stanley Miller & Harold Urey set up Oparin’s hypothesis. • The experiment was successful as it produced organic molecules from inorganic substances.

46. Life on Earth? • From 4.6 to 3.6 billion years ago the earth was very inhospitable. • By 3.9 billion, the earth cooled and water vapor condensed in the atmosphere, filling the oceans for millions & millions of years.

47. Life on Earth? • Primordial soup - pools of water that contain the essential ingredients for life. It is Alive!!!

48. Life on Earth? • Simple organic (carbon) molecules changed into proteins, carbs & nucleic acids. • Protocells are formed from the complex organic molecules. Protocells are the first cells(a living thing enclosed by a membrane). • Protocells formed between 3.9-3.5 billions of years ago. Examples of Protocells; microsphere & coacervates

49. Life on Earth? • Prokaryotes - cells that lack organelles. evolved from protocells. no O2 in atmosphere, therefore anaerobic heterotrophs - consumed organic molecules • Autotrophs (make their own food) evolved after prokaryotes make glucose by chemosynthesis, not photosynthesis • Photosynthetic prokaryotes evolved due to an increase in atmospheric O2 levels.

50. Life on Earth? • Eukaryotes - cells that contain organelles. as O2 levels rose lightning converted much of the O2 into ozone. this ozone layer protected more advance organisms, such as eukaryotes. asmmm2