2. What is Evolution? A change in an organism over time Process in which modern organisms have descended from ancient organisms Populations evolve, NOT individuals

4. Who was Charles Darwin? A scientist that lived in the 1800’s He was a Naturalist He came up with the Idea of Evolution by Natural Selection

5. What did Darwin Accomplish? Sailed on the H.M.S Beagle –Collected fossils & made observations from around the world Wrote the book On The Origin of Species

6. What did Darwin find on the Galapagos Islands? The Animal Species on the Galapagos Islands live no where else in the world. Each island had different climates, species, and food sources. Darwin wondered if the species living on the different islands were once all part of the same species

7. Darwin’s Route:

9. How do Organisms Change Over Time? Through Natural Selection & Artificial Selection.

10. What is Artificial Selection? Selection done on purpose by humans for breeding useful traits into different organisms EX: Breeding Dogs for certain fur color Breeding faster Race Horses Creating bigger fruits & vegetables

12. What is Natural Selection? The Process in which individuals that are better suited to their environment survive and reproduce most successfully

16. How did Darwin’s Finches show Natural Selection? There was a different type of Finch on each island. Each type of Finch had a different beak.

17. Why were the beaks different? Each island had different types of food (seeds, flowers, etc.) The Finches on each island adapted to the food that was available to them Each Island’s Finches evolved over time to having different size and shape beaks that were best suited for the different island environments.

18. What did this all lead to? Finches with beak differences allowed them to….. –Successfully feed –Successfully compete –Successfully reproduce  This led to Natural Selection

20. What 4 Things Must be Present for Natural Selection to Occur? 1.Genetic Variation 2.Overproduction 3.Competition 4. Survival of the Fittest

21. What is Genetic Variation? Variations that come from DNA mutations and gene shuffling between homologous chromosomes that result from sexual reproduction.

22. What is Overproduction? Organisms reproducing more than the environment can handle. Some organisms survive while others do not. Overproduction leads to competition

23. What is Competition? The struggle for existence –Organisms compete for food, living space and mates. Male Frogs Competing for a Female Frog.

24. What is Survival of the Fittest? Individuals that are better suited to their environment are the ones that survive to reproduce.

25. What Evidence Supports Darwin’s Ideas? Fossil record Comparative anatomy Vestigial organs Comparative embryology Molecular biology

26. Discuss the Fossil Record Fossils are the preserved remains of ancient organisms The Fossil Record provides evidence about the history of life on Earth –Most fossils form in sedimentary rock

27. How are fossils dated? Relative dating is a method of determining fossils age by comparing its placement with other fossils in rock layers –Doesn’t show exact age of fossil

28. Relative Dating Fossils that are found in a lower layer are older than fossils that are found in a higher layer

29. What is Radioactive Dating? A technique to calculate the age of fossils based on the amount of remaining radioactive isotopes it contains Age of fossil is based on half- lives

30. What is a Half Life? The length of time required for half of the radioactive atoms in a sample to decay For Example: –Carbon-14 has a half life of 5,730 years –So if you start with 100 grams of Carbon-14, you will only have 50 grams left after 5,730 years!

31. What is Comparative Anatomy? Comparing the parts of organisms for similarities in structure and function to see if the organisms came from a common ancestor.

32. What are Homologous Structures? Structures of different animals that are made up of the same parts but have a different function

33. What do Homologous Structures prove? This gives evidence of common ancestry

34. What are Analogous Structures? Structures that are made differently, but have the same function EX: Wings of a bug, bird and bat

35. What is a Vestigial organ? Structures that were functional in your ancestors, but are no longer used in the body Structures that serve little or no function Structures may be reduced in size Shows Evidence of change over time

36. What are examples of Vestigial Organs? Pelvic Bone in Whales Wisdom Teeth in Humans Appendix in Humans

37. What is Comparative Embryology? Comparing the formation and development of embryos of different species.

38. Comparative Embryology

39. What does this show us? Early stages of development in many vertebrates are very similar –shows common ancestry –human embryos have gills and a tail They have the same: –Development order –Similar tissues and organ structure

40. Born with a Human Tail ! Very Rare – Less than 40 Cases Ever Recorded

42. What is Molecular Biology? The study of the Genes of organisms to see if they show important similarities at the DNA level DNA similarities can show evolutionary relationships The greater the similarities in DNA, the more related they are

45. Who are we related to? The genome of Chimps and Humans are 96% similar – which means chimpanzees have 96% of the same DNA as us! Despite the similarities, scientists still identified 40 million differences among the three billion DNA nucleotides, in each genome.

46. What are some other Theories of Evolution ? 1. Gradualism ( James Hutton ) 2.Uniformitarianism (Charles Lyell) 3. Acquired Characteristics (Lamarck)

47. What is Gradualism? James Hutton (1700’s) Said that Changes on Earth formed slowly but were continuous These changes take millions of years What did this tell Darwin? –If the Earth could change over time, then organisms could have changed over time

48. What is Uniformitarianism? Charles Lyell (1800’s) Geologic processes have not changed throughout Earth’s history – they’ve remained constant Ex: erosion, & volcanoes have occurred and still occur

49. Who was Lamarck? The first scientist to say that organisms changeover time Proposed how specific adaptations evolve in organisms

50. What are Lamarck’s Theories on Evolution? 1.) Use and Disuse Theory: you could alter the size or shape of body structures by using them in new ways –If you don’t use it, you lose it! EX: Wings of birds such as Ostriches & Penguins who don’t have wings to fly anymore!

51. Lamarck’s Theories Continued : 2.) Acquired Characteristics: his idea that an organism can pass on characteristics that it acquired during its lifetime to its offspring  EX: Neck of Giraffe

52. Lamark’s theory of Acquired Characteristics

53. Lamarck’s theories are INCORRECT

54. What are Patterns that are seen in Evolution?

55. 1.) Extinction - Is the total disappearance of a species Usually happens because of competition for resources and habitat 99% of all species that have ever lived are extinct

56. 2.) Coevolution - when 2 species evolve in response to changes in each other & they depend on each other for survival For Example: Bumble bees pollinating flowers & the Acacia Ant living on the Acacia Tree

57. 3.) Adaptive Radiation When one common ancestor develops into many species each adapts to a different environment For Example: Darwin’s Finches & the California Salamanders (Click for video)

58. 4.) Convergent Evolution When distant related species evolve similar features For Example: Swimming appendages: dolphins, sharks & reptiles

59. What are 3 Ways Natural Selection can Affect Phenotype Distribution?

60. Directional Selection Organisms at one extreme or the other survive better than the others. An Example: In this habitat, the Birds with Large beaks are able to survive better than the birds with Small or Medium Beaks Directional Selection Food becomes scarce. Key More Live; they can get food More Die, they can’t get food Large

61. Stabilizing Selection Organisms in the middle of the curve have a higher survival rate For Example: More birds survive that are born with a medium birth weight than those born with a heavier or lighter weight birds Stabilizing Selection Key Percentage of Population Birth Weight Organisms at each end, or at the extremes, have a lower chance of survival Low mortality, high fitness High mortality, low fitness Stabilizing Selection

62. Disruptive Selection More organisms at the upper and lower ends of the curve survive better than those near the middle For Example: Birds with small and large beaks have a higher survival rate than birds with a medium beak Disruptive Selection Largest and smallest seeds become more common. Number of Birds in Population Beak Size Population splits into two subgroups specializing in different seeds. Beak Size Number of Birds in Population Key Low mortality, high fitness High mortality, low fitness