Aim: What makes a Scientific theory credible?

1. Table of Contents Aim: What makes a Scientific theory credible? HW: Preview 190-200 NB 74 Do Now: When someone tells you a story, how do you know whether to believe them or not?

2. Ideas About Evolution 1 Hypothesis of Acquired Characteristics • In 1809, Jean Baptiste de Lamarck suggested that characteristics, or traits, developed during a parent organism’s lifetime are inherited by its offspring. • His hypothesis is called the “inheritance of acquired characteristics”.

3. Ideas About Evolution 1 Hypothesis of Acquired Characteristics • According to this theory individual changes made, would be passed on. • Ex: exercise-muscular body • Exposure to sun- Darker color skin

4. Lamark’s Theory did not have evidence!

5. Charles Darwinhttp://www.pbslearningmedia.org/resource/tdc02.sci.life.evo.lp_darwin/charles-darwin/ Video: Who was Charles Darwin 1. What characteristics made Darwin especially well suited for science? 2. What did Darwin see and do on his five-year voyage aboard the Beagle? 3. Why was the publication of On the Origin of Species a courageous act?

6. Letters from DarwinQuestions to consider:What kinds of questions was Darwin trying to answer?What observations did he make?What follow-up questions would you ask on these topics?How did he use the evidence he collected to form hypotheses?How did he use this evidence and much more to create a theory about evolution?How was Darwin's scientific process similar to and different from that used by scientists today (e.g., Cameron Currie)?More to consider:Explain and discuss the reasons why Darwin was so persistent in his efforts to test plant seeds of various types for viability after soaking them in fresh and salt water for long periods of time?What evidence do these letters reveal about the way Darwin proposed and then tested hypotheses critical to his developing theory?There are many different definitions of "the scientific method" -- most of which are too cut-and-dried for general consumption to be of much real value. Consider the following statement about the scientific method, and discuss whether it seems to apply to Darwin's strategy as expressed in these letters: "The process of science making is narrative. It consists of spinning hypotheses about nature, testing them, correcting hypotheses, and getting one's head straight. En route to producing testable hypotheses, we play with ideas, try to create anomalies, try to find neat puzzle forms that we can apply ... . Our instruction in science from start to finish should be mindful of the lively process of science making, rather than being an account only of "finished science" as represented in a textbook." Bruner, Jerome. 1996. The Culture of Education, Cambridge, MA: Harvard University Press. p. 127.

7. Ideas About Evolution 1 Early Models of Evolution • Change in inherited characteristics over time is evolution.

8. Science Probe

9. What are different types of adaptations that help an animal survive? • HW: NB 74 (skim 190-197) • Do now: Think of an animal and what is special about it that helps it survive. • You may use books to help you

10. Adaptations • -A variations about an organism that helps it survive • 3 main types – body parts, body coverings and behavior • Species to survive: food/nutrients, reproduce, defense, shelter, water

11. Body Parts • How might these adaptations help? • webbed feet, -swim, walk on slippery lsurface • sharp claws,defense, climing, feeding, running • whiskers,-sensors “HEAR or SEE” • sharp teeth, defend and feed • large beaks, open food, store food, feed young • wings,- fly- defense, migrate, get food • hooves.- running – get food, defend, kicking

12. What behaviors might be considered an adaptation?

13. Body Coverings • Hair • Stripes/spots • Bright colored feathers • Scales/plated body

15. Ideas About Evolution 1 Aim : What evidence did Darwin have to support his theory? • HW: NB 75.

16. Ideas About Evolution 1 Darwin’s Observations • Darwin observed 13 species of finches on the Galápagos Islands. • He noticed that all 13 species were similar, except for differences in body size, beak shape, and eating habits. • He also noticed that all the Galápagos finch species were similar to one finch he had seen on the South American coast.

18. Ideas About Evolution 1 Darwin’s Observations • Darwin reasoned that the Galápagos finches must have had to compete for food. • Finches with beak shapes that allowed them to eat available food survived longer and produced more offspring than finches without those beak shapes. • After many generations, these groups of finches became separate species.

19. Hibernation • Migration • Raising young • Finding food • Communication • hide

20. Ideas About Evolution 1 Darwin’s Theory • Darwin’s ideas became known as the Theory of Evolution by Natural Selection. • Natural selection means that organisms with traits best suited to their environment are more likely to survive and reproduce. “survival of the fittest”

22. Industrial Revolution

23. Peppered Moth Simulation http://www.techapps.net/interactives/pepperMoths.swf

24. Adaptations for Hunters • Which color was easiest to find? • How would this effect the survival rate of this “species”. Why?

25. HW RD Notebook 76 What does variation and adaptations have to do with a species survival?

26. Ideas About Evolution 1 Variation and Adaptation • A variationis an inherited trait that makes an individual different from other members of its species. • Variations result from permanent changes, or mutations, in an organism’s genes.

27. Ideas About Evolution 1 Variation and Adaptation • If individuals with these variations continue to survive and reproduce over many generations, a new species can evolve.

28. Ideas About Evolution 1 Variation and Adaptation • An adaptation is any variation that makes an organism better suited to its environment. • Camouflage is an adaptation.

29. Ideas About Evolution 1 Changes in the Sources of Genes • Over time, the genetic makeup of a species might change its appearance. • Many kinds of environmental factors help bring about changes.

30. Ideas About Evolution 1 Geographic Isolation A small number of individuals are isolated from the rest of the population • Gene mutations can occur that add variations to populations. Over time, the two populations can become so different that they no longer can breed with each other.

31. Ideas About Evolution 1 Gradualism • The model that describes evolution as a slow, (100’s of millions of years) ongoing process by which one species changes to a new species is known as gradualism.

32. Ideas About Evolution 1 Punctuated Equilibrium • According to the punctuated equilibrium model, rapid evolution comes about when the mutation of a few genes results in the appearance of a new species over a relatively short period of time.

33. 1.On a piece of paper write the word “TRAIN”. 2.Add, subtract or change one letter to make a new word. 3.Repeat step 2 with the new word. 4. Repeat 3 more times Make a family tree- that shows how your first word changed over time. Try This

34. Clues About Evolution 2 Aim: What evidence is there to support the theory of evolution? • Do Now: What is a fossil?

35. Clues About Evolution 2 Types of Fossils • Most of the evidence for evolution comes from fossils. • A fossil is the remains, an imprint, or a trace of a prehistoric organism. • Most fossils are found in sedimentary rock.

36. Clues About Evolution 2 Types of Fossils • The fossil record provides evidence that living things have evolved.

37. Clues About Evolution • Generally; younger rock layers are deposited on top of older rock layers. 2 Relative Dating • Relative dating provides only an estimate of a fossil’s age.

38. Clues About Evolution 2 Fossils and Evolution • By looking at fossils, scientists conclude that many simpler forms of life existed earlier in Earth’s history, and more complex forms of life appeared later.

39. Fossil activity

40. How Scientists use fossils to develop theories? • What is a homologous structure? • -Similar structure in different species • What is a vestigial structure? Give an example. A structure that doesn’t seem to have a function anymore • Tonsils, appendix, wisdom teeth

41. The Evolution of Primates 3 What do all primates have in common? HW #65 TXT Read 206-209 NB p.80

43. The Evolution of Primates 3 Primates: Humans Monkey and Apes • Having an opposable thumb • allows you to cross your thumb • over your palm and touch your • fingers. • An opposable thumb allows tree-dwelling primates to hold on to branches. • This enables primates to : • Grasp, hold things

44. The Evolution of Primates 3 Other Trait Primates have in common • Binocular vision Let’s you see depth or distance with your eyes. • Flexible shoulders – give a greater range of motion

45. The Evolution of Primates 3 Hominids • About 4 million to 6 million years ago, humanlike primates appeared that were different from other primates. • These ancestors, called hominids, ate both meat and plants and walked upright on two legs. • Hominids shared some characteristics with gorillas, orangutans, and chimpanzees, but a larger brain separated them from the apes.

46. The Evolution of Primates 3 African Origins • In the early 1920s, a fossil skull was discovered in a quarry in South Africa. The skull had a small space for the brain, but it had a humanlike jaw and teeth. • The fossil, named Australopithecus, was one of the oldest hominids discovered.

47. The Evolution of Primates 3 African Origins • An almost-complete skeleton of Australopithecus was found in northern Africa in 1974. • This hominid fossil was called Lucy and had a small brain but is thought to have walked upright. • This fossil indicates that modern hominids might have evolved from similar ancestors.

48. The Evolution of Primates 3 Early Humans • In the 1960s in a region of Africa, a hominid fossil, which was more like present-day humans than Australopithecus, was discovered.

49. The Evolution of Primates 3 Early Humans • The hominid was named Homo habilis, meaning “hand man.” because simple stone tools were found near him. • Homo habilis is estimated to be 1.5 million to 2 million years old.

50. The Evolution of Primates 3 Early Humans • Based upon many fossil comparisons, scientists have suggested that Homo habilis gave rise to another species, Homo erectus, about 1.6 million years ago. • This hominid had a larger brain than Homo habilis. • Homo erectus traveled from Africa to Southeast Asia, China, and possibly Europe.