1. Theory of Evolution

2. WRITE A DEFINITION: gradual change over time; the process by which modern organisms have descended from ancient organisms a well-supported testable concept that is backed-up by evidence Concept has been tested multiple times and is proven EVOLUTION : THEORY :

4. Ideas that shaped Darwin’s thinking: James Hutton (1795)- the EARTH was shaped by geological forces occurring over very long periods of time, and the Earth is millions of years old.

5. Ideas that shaped Darwin’s thinking: Charles Lyell (1830)- the geological processes still occurring now have shaped Earth’s features over long periods of time http://www.biologydaily.com/biology/Sir_Charles_Lyell

6. Formation of Earth The Earth is about 4.8 billion years old According to science, the Earth was put together piece by piece over the course of about 100 million years

7. Early Earth Atmosphere Earths early atmosphere was made up of 6 main things: Hydrogen cyanide Carbon dioxide Carbon monoxide Nitrogen Hydrogen sulfide water Could you have lived on early Earth?

8. Cooling of the Earth Not only was the atmosphere not suitable for life the early Earth was VERY hot About 4 billion years ago the earth began to cool –Rocks formed on the earths surface

9. Formation of water 3.8 billion years ago the earth cooled even more –Liquid was able to remain on the earths surface forming the first oceans video

10. Free Oxygen Fossils of prehistoric bacteria have been found in rocks that are dated to be more the 3.5 billion years old 2.2 b.y.a. Photosynthetic bacteria began producing oxygen as a by product of photosynthesis

11. Free Oxygen Free oxygen mixed with iron in the ocean forming iron oxide Oxygen gas started accumulating in the atmosphere, forming the ozone layer Increased oxygen levels caused some life forms to go extinct and allowed other life forms to evolve

12. Ideas that shaped Darwin’s thinking: Theory of Pangaea- All land was at one time connected

14. Ideas that shaped Darwin’s thinking: Continental drift- shifting of the earths continent/ crust convergent divergent Transform

15. Division of Life on Earth Life on Earth is divided into Eras and Periods –Eras are bigger than periods Based on fossil evidence –major changes that occurred in the Earth’s climate and geography affected the living organisms

16. Darwin’s Theory of Evolution The Puzzle of Life’s Diversity Chapter 15-1 Image from: Biology by Miller and Levine; Prentice Hall Publishing©2006

17. Charles Darwin- The person who contributed the most to our understanding of evolution In 1831, he joined the crew of the Beagle as a naturalist for a 5 year voyage around the world.

18. The Fossil Record Fossil record showed 2 types of organisms –Ones that were similar to animals and plants alive at the time –Ones that were different to animals an plants alive at the time Why had these species disappeared? –99% of all species that have ever lived on Earth are extinct

19. Fossils and Ancient Life What is a fossil? –Hardened remains of plant or animal in rock Why do scientist use fossils? Fossils allow us to infer what past life forms were like –Structure –Predator/Prey –Habitat

20. How Fossils Form After the organism dies the remains must be preserved The dead organism is buried by sediment –Mud –Sand –dust

21. How Fossils Form Different types of fossils can be formed –Eggs –Foot prints –Bones –Leaves

22. Relative Dating Most fossils form in sedimentary rock –formed by the deposition of materials at the Earth’s surface The age of a fossil is determined by comparing its placement with that of fossils in other layers of rock –Layers of sedimentary rock are built from oldest to newest

23. Index Fossil Fossils used to define and identify geological time –When the organisms lived Species that existed for a short period of time over a wide geographic range

24. Radioactive/Radiometric Dating Uses radioactive elements to determine how old the rock is –Radioactive elements decay at a steady rate –The use of half-lives to determine the age of a sample –Half life: the length of time required for half of the radioactive atoms to decay To date older rocks you must use elements with longer half- lives Carbon-14 (5,730 years) Uranium (half-life: 4.47 b.y.)

25. How the fossil record is used used to show change in organisms over time –Evidence of gradual change life on earth is divided based on changes in the fossil record –Transitions marked by extinction –Extinction makes new habitats available to species

26. DARWIN WONDERED? Why do Argentina and Australia have different Animals even though they have similar grassland? Why have so many species disappeared? How are these extinct species related to living species?

27. Ideas that shaped Darwin’s thinking: Jean-Baptiste Lamarck (1830)- one of first scientists to recognize living things changed over time and that all species were descended from other species. Lamarck's Hypothesis: 1.Tendency towards perfection 2.Use and disuse 3.Inheritance of acquired traits

28. Tendency Towards Perfection Innate tendency toward complexity and perfection Organisms are continuously changing and acquiring traits that benefit them

29. The male fiddler crab uses its front claw to attract mates and fight off predators. Through repeated use, the front claw becomes larger. The fiddler passes on this acquired characteristic to its offspring Use and Disuse By selective use or disuse of organs, organisms acquire or loose traits during their life time These traits are passed down to offspring

30. Inheritance of Acquired traits Acquired traits could be passed on to offspring –Lamarck didn’t know about genes and how traits are inherited. If you lifted weights your whole young adult life, and then you had children, would your kids be more muscular?

31. Inheritance of Acquired traits

32. What’s wrong with Lamarck’s hypotheses? Individuals DO NOT evolve –You cannot change your DNA Acquired traits cannot be passed down to offspring An organisms behavior has no effect on its heritable characteristics

33. What’s right with Lamarck’s hypothesis? Lamarck recognized that organisms are Adapted to their environment

34. competition Evolution= Inherited adaption's that accumulate in a population over many generations What does drive evolution?

35. Charles Darwin spent one month observing life on the Galapagos Islands. There, he encountered some unique animals, such as finches and tortoises. http://www.darwinadventure.com/pictures/galapagos_giantortoise.jpg http://mikebaird.com/ecuador/images/galapagos_off_ecuador_ng_map.jpg Darwin's greatest influence

36. A summary of Darwin’s Theory 1.Individual organisms differ and some of the variations are genetic WHY DOES VARIATION MATTER?

37. The Galapagos Islands are close together but have very different climates. hot and dry, with little vegetation more rainfall and were rich in vegetation Each island had its own unique Assortment of plant and animal species. Biology by Miller and Levine; Prentice Hall Publishing©2006

38. Inherited Variation Inherited variation- passed from parents to offspring How are traits passed from parents to offspring hint: think about meiosis Crossing over Random lining up of chromosomes

39. A summary of Darwin’s Theory 2.Organisms produce more offspring then can survive, and many that do survive do not reproduce. –High birth rates and a shortage of resources force organisms into competition

40. Ideas that shaped Darwin’s thinking: Thomas Malthus (1798)- If the human population continued to grow unchecked, there would be insufficient living space and food. Individuals adjust to limited resources

41. Natural selection Each individual differs from other members in its species –Each has unique advantages and disadvantages Natural selection- based on their traits, some individuals are able to survive longer then others –Takes place without human control or direction

42. Organisms cannot change their characteristics or force natural selection…

43. Go to Section: Pinta Island Intermediate shell Pinta Isabela Island Dome-shaped shell Hood Island Saddle-backed shell Hood Floreana Santa Fe Santa Cruz James Marchena Fernandina Isabela Tower Giant Tortoises of the Galápagos Islands Section 15-1 On the desert-like Hood Island, tortoises had long necks… …while on the lush rainforest of Isabela Island, tortoises had short necks… and on Pinta Island, tortoise necks were somewhere in between

44. Natural Selection doesn’t give organisms what they need to survive

45. Artificial Selection Artificial selection- nature provided the variation and humans selected for the variations they saw useful. –Used to improve crops and livestock (selective breeding)

46. A summary of Darwin’s Theory 3.Because more organisms are produced then can survive, they compete for limited recourses. –Food –Shelter –Space –Mates

47. The struggle for existence Competition  what drives evolution If there is no competition there is no evolution

48. A summary of Darwin’s Theory 4.Each organism has different advantages and disadvantages in the struggle for existence. Survival of the Fittest- the ability of an organism to survive and reproduce in its specific environment

49. Survival of the Fittest Fitness is a result of adaption's –Adaptation= inherited characteristics that increase an organisms chance of survival Is the most fit animal always the biggest, strongest and fastest?

50. Survival of the Fittest?

51. Adaptation vs. the ability to adapt Adaptation- a trait or characteristic that you re born with Ability to Adapt- How you use your traits or characteristics to survive

52. Individuals DO NOT changes Individuals are unchanging Individuals either live or die based on the traits that they inherited from their parents

53. A summary of Darwin’s Theory 5.Species alive today are descended with modifications from ancestral species

54. Review of Darwin’s Theory Individual organisms differ and some of the variations are genetic Organisms produce more offspring then can survive, and many that do survive do not reproduce. Because more organisms are produced then can survive, they compete for limited recourses. Each organism has different advantages and disadvantages in the struggle for existence. Species alive today are descended with modifications from ancestral species

55. Review of Darwin’s theory Adaptations- an inherited trait or characteristic that is passed down from on generation to the next –NOT something gained during your life time! Acquired traits- are not passed down The ability to adapt- how an organism is able to use their adaptations to their advantage in order to survive in their environment

56. Conditions for natural selection Conditions for natural selection include: Variations exist among members of a population Many more individuals are produced each generation than will survive Some individuals are better adapted so they survive & reproduce Members of a population compete for food, space, mates...

57. Evidence for Evolution Fossil Record Geographic Distribution Homologous Body Structures Similarities in Embryology

58. Fossil record

59. The fossil record is a history of life on Earth –The earth is millions of years old Which scientists proposed this? –Fossils that are found in different rock layers show the evolution of living species over millions of years

60. Fossil Record Transitional fossils-document various intermediate stages in the evolution of modern species

61. Incomplete Fossil Record Not all fossils have been found –We are still finding new fossils –The gaps in the fossil record are getting smaller Not all organisms that ever live become fossilized –Soft bodied organisms are not fossilized –Organisms that don’t die in or by the water are usually not fossilized

62. Geographic distribution when a population gets separated difference selective pressures will work on the populations and cause changes Divergent Evolution- populations evolve separately –Formation of new species

63. Geographic distribution The environment selects for specific adaptations –If the environment is the same in 2 different locations we see the evolution of similar but unrelated species –Convergent evolution- evolution of shared traits in unrelated species Bats and birds

64. Homologous body structures Homologous structures: variations on a body structure that was present in their common ancestor

65. Vestigial Structures structures or organs that seem to serve no useful function –Human  tail bone –Whales  tiny pelvic and limb bones –Ostriches  wings vestigial structures show common ancestry with organisms in which the homologous structure is still functional.

66. Similarities in Embryology The early stages of development are similar in different species –All animals with backbones The same groups of embryonic cells develop in the same order and pattern –Cause for homologous structures

67. Descent with modification Natural selection produces organisms that have different characteristics –Species today look different then their ancestors Common descent: All living organisms are related to one another –A single tree of life links all living organisms