Clicker Question Which is an example of deductive reasoning?

2. Clicker QuestionWhich is an example of deductivereasoning? • The population of the USA is over 300 million. • I measured the body temperature of hundreds of Mexican free-tailed bats and concluded that they do not hibernate. • Webster’s dictionary says that birds are warm blooded, have feathers and wings. Archaeopteryx is a fossil vertebrate and has wings & feathers. Based on the definition, I would guess that it probably was warm blooded. • The first time I saw a kangaroo I saw that it had a pouch, from that time on I looked for pouches in all of them.

3. Clicker QuestionWhich is an example of inductivereasoning? • Planets have an elliptical orbit; they are round in shape and are large. Pluto has these characteristics and so it is a planet. • I dissected two squid and noticed there were 3 chambers in the heart. I think that it is likely that all squid have 3 chambered heats. • Hybrid cars get more miles/gallon than conventional cars. I just bought a Prius hybrid. I expect to get great gas mileage.

4. And now the lecture.Why did Darwin change his mind about the world & its organisms?

5. Remember the Hypothetico-Deductive Method QUESTIONS • HOW DO WE ACCOUNT FOR THE • ORIGIN? • DIVERSITY? • ADAPTATION • SCALA NATURAE? of organisms

6. HYPOTHESES: DEVINE CREATIONEVOLUTION 1.Sudden creation from nothing 1. No information on the Origin 2. Young Earth (~ 6,000 years) 2. Old Earth (millions of years) 3. Fixity of species 3. Species change over time 4. Separate ancestry for 4. Common ancestry for humans & apes humans & apes 5. The “Deluge” explains the 5. The “Deluge” doesn’t explain the presence & distribution of presence & distribution of fossils fossils

7. Shift towards evolution….because • Religious dogmatism began to weaken • Protestant Reformation occurred Pentecostal Church Methodists Unitarians Episcopalians Baptists Presbyterians Anglicans 1517 Lutherans Mennonites Catholic Church

8. EVOLUTIONOF CHRISTIANITY

9. Shift towards evolution….because • Shift from religious to secular reasoning Science began to explain things that used to be inexplicable

10. SCIENTIFIC ADVANCES • Telescope:Earth is NOT the center of the Universe • Microscope: Microbes exist & cause disease

11. SCIENTFIC ADVANCES • Fossils • Show change over time • Show extinction—are there fewer species now then at the time of creation? • Voyages of Discovery • Many species found that were not mentioned in the Bible e.g. kangaroos, giant moa birds

12. SCIENTFIC ADVANCES • Geology • Evidence of an old Earth • Biology Lamarck & Darwin argued for evolution & came up with mechanisms which were • testable, • not supernatural, • could be modified • Led to predictions

13. DARWIN’S HYPOTHESIS of Evolution By Natural Selection • Individuals vary • Populations tend to over-breed • Struggle for existence • Survival of the fittest • Variations are inherited • New species develop So organisms on earth change through time

14. DARWIN’S EVIDENCE I

15. DARWIN’S THREE CLUES #1) Populations close together are similar. Populations far apart are different. Suggests that a species can vary with the environment and that species are not fixed.

16. DARWIN’S THREE CLUES #2 Fossil and living armadillos exist together Suggests that the ancestral fossil species gave rise to the modern species

17. DARWIN’S THREE CLUES #3 Galapagos Islands: ~14 volcanic islands with very similar species that are related to the ones on the mainland. . Suggests that species probably immigrated from the mainland and then specialized for the different islands’ environments

18. So if Evolution did occur how did it happen? Let’s use the Hypothetico-Deductive method: We have the Question. We have the Hypothesis. What are the predictions and what kind of evidence could Darwin bring to bear on the problem?

19. Deduction (Prediction) 1: • If the hypothesis of evolution by natural selection is correct thenvariations should exist among domestic organisms Data

20. And everyone knew that this great variation was due to artificial selection And that it was fast and powerful. No one thought that a new breed of cattle was due to God the Creator. Breeders could not cause variation but they could take advantage of it when it occurred, said Darwin.

21. Could something similar be going on in wild populations? • Ifthe hypothesis of evolution by natural selection is correct then variations should exist among wild populations Data

22. DATA Human Variation Evaluation?

23. What should we conclude? • The data prove the hypothesis • The data disprove the hypothesis • The data support the hypothesis • The data do not support the hypothesis • As Francis Bacon said, we should not make conclusions, just collect data.

24. Deduction (Prediction) 2 • Ifthe hypothesis of evolution by natural selection is correct then more offspring are born than will survive to reproduce Test: Compare number born & their survival

25. Data e.g. An orchid can produce a million seeds

26. Data e.g. A salmon might produce 28 million eggs/season

27. Data e.g. An oyster can produce 100 million eggs/spawning

28. Data A puffball fungus can produce billions of spores Evaluation: Many are born & few survive SPORES

29. In spite of the enormous potential to overbreed, populations tend to stay the same size

30. Deduction (Prediction) 3 • Ifthe hypothesis of evolution by natural selection is correct then differences should exist among offspring that survive & breed & those that don’t. Test: Look for differences Not all organisms are created equal

31. Data Difficult to obtain—natural selection is slow Darwin argued that Natural Selection must occur

32. When you heard Darwin speak last Friday, what was the most compelling argument Darwin offered for NaturalSelection being the causative agent for evolution? Clicker Question • He argued mutation could not do it alone • He used the analogy of artificial selection • He used the fossil record as evidence • He used pesticide resistance in insects as evidence of natural selection • He argued that Thomas Malthus said that over-population could cause evolution

33. Selection In the farm yard, the farmer decides who survives and lives to breed. Those individuals with the preferred traits are the ones chosen to breed and pass their traits on to the next generation--- ARTIFICIAL SELECTION. Nature could do the same thing. Organisms that have better variations would have an advantage and survive--- NATURAL SELECTION

34. Data Evaluation: Natural selection is probable (Darwin) Natural selection in certain (Today) Data support the hypothesis

35. Deduction (Prediction) 4 • Ifthe hypothesis of evolution by natural selection is correct, then variations important to survival must be inherited. Test: No good test available (Darwin’s time) Inheritance not understood, but we can look at the artificial selection on the farm.

36. Data Chickens produce Chickens NOT

37. Data Cows produce cows NOT

38. Evaluation Traits are usually passed on. Data support the hypothesis…….But…….. But any conclusion is not strong because we don’t understand heredity And…… Artificial Selection had not produced one new species !

39. And….There is the FleemingJenkin’s argument Good traits will be swamped out by breeding!

40. I am puzzled Don’t worry Mendel will save you

41. Deduction (Prediction) 5 • Ifthe hypothesis of evolution by natural selection is correct then the Earth must be old so that evolution had time to occur. Test: Look at the geological record

42. The world is too young. There is not enough time for evolution to have occurred. “It matters not what you would prefer but what is true.” It is a matter of evidence

43. DATA Depth of the canyons suggests age

45. Data Thickness ofthe rock strata suggests age

46. Evaluation Earth’s age is unknown (Darwin) Earth appears to be old (Geology) Consilience occurs !

47. So far all predictions are correct: • Organisms do vary • Populations do tend to over breed • There must be a struggle for existence because there are not enough resources to sustain an exponential population growth. • This must lead to a survival of the fittest—i.e. natural selection must occur. • We don’t know how these successful variations can be inherited but traits are passed in some way; they are inherited • There is strong evidence that the earth is millions of years old, enough time for evolution to occur

48. We need more evidence ! We’ll talk about it next time