14.1 Fossil Evidence of Change

1. The History of Life Chapter 14 14.1 Fossil Evidence of Change Land • Earth formed about 4.6 billion years ago. • Gravity pulled densest elements to center of planet. • After ~500 million years, solid crust formed on surface.

2. The History of Life Chapter 14 14.1 Fossil Evidence of Change Atmosphere • Gases that likely made-up atmosphere were expelled by volcanoes. • Water vapor (H2O) • Carbon dioxide (CO2) • Sulfur dioxide (SO2) • Carbon monoxide (CO) • Hydrogen sulfide (H2S) • Hydrogen cyanide (HCN) • Nitrogen (N2) • Hydrogen (H2)

3. The History of Life Chapter 14 14.1 Fossil Evidence of Change Clues in Rocks • A fossil is any preserved evidence of organism. • Most organisms DO NOT • end up as fossils. They decompose before they become fossils.

4. The History of Life Chapter 14 14.1 Fossil Evidence of Change

5. The History of Life Chapter 14

6. The History of Life Chapter 14 14.1 Fossil Evidence of Change Fossil Formation • Nearly all fossils are formed in sedimentary rock. • Sediments build-up until they cover organism’s remains. • Minerals replace organic matter or fill empty pore spaces of organism.

7. The History of Life Chapter 14 14.1 Fossil Evidence of Change Fossil Formation • http://www.teachersdomain.org/resource/tdc02.sci.life.evo.becfossil/ • ~ video clip of Lucy becoming a fossil • Discovered by Donald Johanson and Tom Gray in 1974 at Hadar in Ethiopia. • Its age is about 3.2 million years. • Lucy was an adult female of about 25 years and was assigned to the species Australopithecus afarensis. • About 40% of her skeleton was found, and her pelvis, femur (the upper leg bone) and tibia show her to have been bipedal, although there is evidence that afarensis was also partly arboreal (tree-dwelling). • She was about 107 cm (3'6") tall (small for her species) and about 28 kg (62 lbs) in weight.

8. The History of Life Chapter 14 14.1 Fossil Evidence of Change Dating fossils • Relative datingis a method used to determine the age of rocks by comparing them with those in other layers. • Law of superposition

9. The History of Life • Radioactive isotopes that can be used for radiometric dating are found only in igneous or metamorphic rocks. Chapter 14 14.1 Fossil Evidence of Change Radiometric Dating • Uses decay of radioactive isotopes to measure age of rock

10. The History of Life Chapter 14 14.1 Fossil Evidence of Change The Geologic Time Scale • A model that expresses the major geological and biological events in Earth’s history. • Divided into the Precambrian eon and the Phanerozoic eon. • Phanerozoic eon includes the Paleozoic, Mesozoic, and Cenozoic eras. • Each era is divided into one or more periods.

11. The History of Life Chapter 14 14.1 Fossil Evidence of Change Precambrian • Nearly 90 percent of Earth’s entire history, (formation of Earth to the beginning of the Paleozoic era about 542 million years ago) • Autotrophic prokaryotes enriched the atmosphere with oxygen.

12. The History of Life Chapter 14 14.1 Fossil Evidence of Change The Paleozoic Era • The ancestors of most major animal groups diversified in the Cambrian explosion. • Life in the oceans continued to evolve at the end of the Cambrian period. • Fish, land plants, and insects appeared during the Ordovician and Silurian periods. • The first tetrapods emerged in the Devonian.

13. The History of Life Chapter 14 14.1 Fossil Evidence of Change • A mass extinction ended the Paleozoic era at the end of the Permian period. • Between 60 and 75 percent of the species alive went extinct.

14. The History of Life Chapter 14 14.1 Fossil Evidence of Change The Mesozoic Era • Mammals and dinosaurs first appeared late in the Triassic period, and flowering plants evolved from nonflowering plants. • Birds evolved from a group of predatory dinosaurs in the middle of the Jurassic period. • About 65 million years ago, a meteorite struck Earth.

15. The History of Life Chapter 14 14.1 Fossil Evidence of Change • Plate tectonics describes movement of several large plates that make up surface of Earth. • These plates move on top of a partially molten layer of rock underneath.

16. The History of Life Chapter 14 14.1 Fossil Evidence of Change The Cenozoic Era • Mammals became the dominant land animals. • mammals of all kinds began to diversify.

17. The History of Life Chapter 14 Origins: Early Ideas • Spontaneous generation- idea that life arises from nonlife. • Francesco Redi, Italian scientist, tested and disproved idea that flies arose spontaneously from rotting meat.

18. The History of Life Chapter 14 • Theory of biogenesis- only living organisms can produce other living organisms. • Louis Pasteur designed experiment to show biogenesis was true even for microorganisms, like bacteria.

19. The History of Life Chapter 14 Origins: Modern Ideas • Simple organic molecule formation • Primordial soup hypothesis was early hypothesis about origin of life. • Organic molecules could have been made from simple reactions. • UV light from Sun and electric discharge in lightning might have been primary energy sources.

20. The History of Life Chapter 14 • Stanley Miller and Harold Urey – 1st to show that simple organic molecules could be made from inorganic compounds.

21. Replication of the Urey-Miller experiment. By passing electrical sparks through mixtures of hydrogen, methane, ammonia, and water vapor, scientists produced colored amino acids, building blocks of organic life. The experiment was first performed by Stanley Miller in 1953 and has been repeated many times elsewhere. These photographs show an experiment at NASA-Ames Research Center's Chemical Evolution Branch.

22. The History of Life Chapter 14 Making Proteins • Life requires proteins. • One possible mechanism for formation of proteins would be if amino acids were bound to clay particles.

23. The History of Life Chapter 14 Genetic Code • Some RNA sequences have changed very little through time. • Many biologists consider RNA to have been life’s first coding system. • Other researchers proposed that clay crystals could have provided an initial template for RNA replication.

24. The History of Life Chapter 14 Cellular Evolution • Scientists hypothesize that first cells were prokaryotes. • Many scientists think that modern prokaryotes called archaea are closest relatives of Earth’s first cells.

25. The History of Life Chapter 14 First Prokaryotes • Archaea are autotrophic. • do not obtain their energy from Sun. • do not need or produce oxygen.

26. The History of Life Chapter 14 Photosynthesizing prokaryotes • Photosynthesizing prokaryotes evolved shortly after archaea. • Prokaryotes, called cyanobacteria, have been found in rocks as old as 3.5 billion years.

27. The History of Life Chapter 14 The Endosymbiont Theory • ancestors of eukaryotic cells lived • with prokaryotic cells. • relationship between cells became mutually beneficial • prokaryotic symbionts became organelles within eukaryotic cells. • This theory explains origin of chloroplasts and mitochondria! So very cool!

28. The History of Life Chapter 14

29. The History of Life Chapter 14 Chapter Resource Menu Chapter Diagnostic Questions Formative Test Questions Chapter Assessment Questions Standardized Test Practice biologygmh.com Glencoe Biology Transparencies Image Bank Vocabulary Animation Click on a hyperlink to view the corresponding feature.

30. The History of Life A B C D Chapter 14 CDQ 1 Chapter Diagnostic Questions Which is an example of the theory of spontaneous generation? Tadpoles become frogs. A starfish can grow from a severed arm. Damp hay and corn create mice. From a tiny acorn, an oak can grow.

31. The History of Life A B C D Chapter 14 CDQ 2 Chapter Diagnostic Questions What gas do scientists think was absent from Earth’s early atmosphere? sulfur nitrogen oxygen water vapor

32. The History of Life A B C D Chapter 14 CDQ 3 Chapter Diagnostic Questions In which period did the first land vertebrates appear? Cambrian Devonian Triassic Mesozoic

33. The History of Life A B C D Chapter 14 FQ 1 14.1 Formative Questions In which type of rock do paleontologists search for fossils? igneous metamorphic sedimentary volcanic

34. The History of Life A B C D Chapter 14 FQ 2 14.1 Formative Questions Which dating method determines the age of rocks by comparing them to rocks in other layers? absolute dating geological dating relative dating sedimentary dating

35. The History of Life A B C D Chapter 14 FQ 3 14.1 Formative Questions Which geological change during the Mesozoic era had the greatest effect in shaping the course of evolution? plate tectonics extensive glaciation increased volcanic activity meteorite impact

36. The History of Life A B C D Chapter 14 FQ 4 14.2 Formative Questions At one time people believed that mold growing on a piece of cheese was created by the cheese. This is the idea of __________. biogenesis transgenesis primordial generation spontaneous generation

37. The History of Life A B C D Chapter 14 FQ 5 14.2 Formative Questions According to the endosymbiont theory, what may have happened to a prokaryotic cell that entered a host cell? It was digested by the host cell. It became an organelle in the host cell. It became a harmful parasite in the host cell. It was removed from the host cell by exocytosis.

38. The History of Life A B C D Chapter 14 FQ 6 14.2 Formative Questions An ancient prokaryote containing photosynthetic pigments that was engulfed by a host cell may have become a _________. chloroplast lysosome centriole ribosome

39. The History of Life A B C D Chapter 14 CAQ 1 Chapter Assessment Questions Which is the half-life of the radioactive isotope shown in the graph? 18 years 36 years 54 years 72 years

40. The History of Life A B C D Chapter 14 CAQ 2 Chapter Assessment Questions Study the graph. Determine the age of a rock if it contained 40% C-14. 2,857.5 years 7,576 years 11,460 years 5,730 years

41. The History of Life A B C D Chapter 14 STP 1 Standardized Test Practice Which factor made it unlikely that life existed on Earth 4 billion years ago? absence of oxygen absence of food intense heat intense sunlight

42. The History of Life A B C D Chapter 14 STP 2 Standardized Test Practice For which fossil might a paleontologist most likely use carbon-14 to determine its age? fossilized microbes in volcanic rock dinosaur footprints found in sedimentary rock marine fossils found in a deep sedimentary layer a woolly mammoth frozen in a glacier since the last Ice Age

43. The History of Life A B C D Chapter 14 STP 3 Standardized Test Practice Beryllium-10 (Be-10) has a half life of about 1.5 million years. If a sample is analyzed and determined to contain ¼ of the original Be-10, what is the age of the sample? 750,000 years 3 million years 4.5 million years 6 million years

44. The History of Life A B C D Chapter 14 STP 4 Standardized Test Practice Which provides the best evidence that a meteorite struck the earth 65 million years ago? a large crater that was found a layer containing high levels of iridium the sudden appearance of mammals the sudden disappearance of dinosaurs

45. The History of Life A B C D Chapter 14 STP 5 Standardized Test Practice In this experiment using water and the gases to simulate Earth’s early atmosphere, which was not one of the final products? amino acids nucleotides RNA molecules sugar molecules

46. The History of Life A B C D Chapter 14 STP 6 Standardized Test Practice Why do scientists believe that archea are the closest relatives to Earth’s first cells? They are eukaryotes. They contain DNA. They carry out photosynthesis. They live in extreme environments.

47. The History of Life Chapter 14 Glencoe Biology Transparencies

48. The History of Life Chapter 14 Image Bank

49. The History of Life Chapter 14 Animation • Visualizing Geologic Time • Continental Drift • Miller-Urey Experiment • Endosymbiont Theory

50. Describe the contributions of Miller and Urey. Be sure to include the gist of their experiment, and what products were formed. • Describe the contributions of Francisco Redi to the theory of spontaneous generation. Be sure to say whether his work supported or refuted spontaneous generation. • Describe the contributions of Louis Pasteur to the theory of spontaneous generation. Be sure to say whether his work supported or refuted spontaneous generation.