1. Organism classification and the scientific method 9/1

2. From the last class-Themes in biology 1.Life is organized in a hierarchy from DNA molecules to the biosphere 2.Living organisms interact with their environments, exchanging matter and energy 3.Cells are the structural and functional units of life 4.All life has common features

3. Three Domains of Life Prokaryotes Single-celled (mostly) No organelles No membrane-bound nucleus Eukaryotes Single or multi-cellular Membrane-bound nucleus Organelles

4. Bacteria (multiple kingdoms) Small in size!

5. Bacteria (multiple kingdoms) The most diverse protists!

6. Extreme environments! Archaea (multiple kingdoms) Colony of archaea composed of many cells 100 o C and pH of 0

7. Archaea (multiple kingdoms) And not-so-extreme environments…

8. Protists (multiple kingdoms) Two major groups we will look at in this course Algae Protozoans

9. Plants, Fungi and Animals can be distinguished by how they get their nutrients

10. Kingdom Plantae Diverse, successful, produce their own food and have cell walls made of cellulose

11. Molds, yeasts and mushrooms Decomposers that recycle nutrients

12. Kingdom Animalia Ingest other organisms for food 900,000+ species of insects may account for ~80% of all animal diversity

14. 1.6 Evolution explains the unity and diversity of life

17. Evolution is a theory. So what does this mean? Theory-an idea that has been rigorously tested, supported and generally accepted to be true. Theories are supported by hypothesis-driven research and results. Copyright © 2009 Pearson Education, Inc.

18. In 1859, Charles Darwin published On the Origin of Species by Means of Natural Selection The book accomplished two things 1. Presented evidence to support the idea of evolution 2. Proposed a mechanism for evolution called natural selection Copyright © 2009 Pearson Education, Inc.

19. Darwin proposed natural selection by connecting two observations 1. Individuals within a population inherit different characteristics and vary from other individuals 2. Populations tend to produce more offspring than can survive to reproduce themselves Copyright © 2009 Pearson Education, Inc.

20. Natural selection is an editing mechanism Heritable variations in populations respond to environmental factors  this favors some individuals over others Over (evolutionary) time this results in evolution of new species adapted to particular environments Evolution is biology’s core theme and explains unity and diversity of life Copyright © 2009 Pearson Education, Inc.

21. Individual variation Observations Overproduction of offspring Natural selection: unequal reproductive success Inferences Evolution of adaptations in a population

22. Common Evolutionary Misconceptions 1. Evolution occurs in a population, not in an individual Mutations happen in an individual 2. Organisms do not choose to adapt Changes occur at random

23. 1 2 Populations develop diverse characteristics as a result of their response to the environment, mutations and exchange with other populations

24. Population with varied inherited traits 1 Elimination of individuals with certain traits 2 Reproduction of survivors 3

25. Evolution can not occur if: 1. There are no differences between individuals of a population. 2.Mortality is not selective. 3.There are no differences in reproduction within a population.

26. Pangolin Killer whale Two examples of adaptive evolution, from a common ancestor

27. Pangolin

28. Killer whale

29. THE PROCESS OF SCIENCE Copyright © 2009 Pearson Education, Inc. 1.7 Scientists use two main approaches to learn about nature

30. Two approaches are used to understand natural causes for natural phenomena 1. Discovery science—uses verifiable observations and measurements to describe science 2. Hypothesis-based science—uses the data from discovery science to explain ideas This requires proposing and testing of hypotheses Inquiry is the heart of science Copyright © 2009 Pearson Education, Inc.

31. Examples of Discovery Science The Human Genome Project Exploration to discover new species

32. Discovery Science: A lost cause? Absolutely not!

33. Here, we make a distinction between theory and hypothesis A hypothesis is a proposed explanation for a set of observations A theory is supported by a large and usually growing body of evidence and is accepted by most scientists Copyright © 2009 Pearson Education, Inc.

34. Lab experiments- The most controlled. Researchers can control most if not all variables. Field experiment- One variable is changed, but the natural environment determines the outcome. Natural experiment- Evolution is a natural experiment. We have very little control over the outcome…or do we? Copyright © 2009 Pearson Education, Inc. There’s ‘more than one way to skin a cat’

35. 1.8 With hypothesis-based science, we pose and test hypotheses We solve everyday problems by using hypotheses An example would be the reasoning we use to answer the question, “Why doesn’t the flashlight work?” Using deductive reasoning we realize that the problem is either the (1) bulb or (2) batteries. The hypothesis must be testable (i.e. Can we design an experiment to directly support our hypothesis?) The hypothesis must be falsifiable (i.e. If it truly is false, can we test it in a way that demonstrates this?) Copyright © 2009 Pearson Education, Inc.

36. Hypothesis #1: Dead batteries Observations Question Hypothesis #2: Burned-out bulb

37. Hypothesis #1: Dead batteries Observations Question Hypothesis #2: Burned-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction

38. Hypothesis #1: Dead batteries Observations Question Hypothesis #2: Burned-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test falsifies hypothesisTest does not falsify hypothesis

39. Hypothesis #1: Dead batteries Observations Question Hypothesis #2: Burned-out bulb

40. Hypothesis #1: Dead batteries Hypothesis #2: Burned-out bulb Prediction: Replacing batteries will fix problem Prediction: Replacing bulb will fix problem Test prediction Test falsifies hypothesis Test does not falsify hypothesis Important! Each hypothesis involved only one factor, or variable. Why wouldn’t we test both hypotheses together by changing the batteries AND light bulb at the same time?

41. 1.8 Case Study Another hypothesis: Mimicry helps protect nonpoisonous king snakes from predators where poisonous coral snakes also live The hypothesis predicts that predators learn to avoid the warning coloration of coral snakes Mimicry – a resemblance of one organism to another, usually in an attempt to evade predators. Copyright © 2009 Pearson Education, Inc.

42. 1.8 With hypothesis-based science, we pose and test hypotheses Experimentation supports the prediction of the mimicry hypothesis—nonpoisonous snakes that mimic coloration of coral snakes are attacked less frequently –The experiment has a control group using brown artificial snakes for comparison –The experimental group is artificial snakes with the red, black, and yellow ring pattern of king snakes Copyright © 2009 Pearson Education, Inc.

43. Eastern Coral Snake (poisonous)

44. Scarlet king snake (non-poisonous)

45. Red on yellow, kill a fellow Red on black, friend of Jack.

46. Coral snake range-blue Eastern king snake range-red

47. Coral snake range-blue Eastern king snake range-red Predators here do not interact with coral snakes (poisonous) Predators here see both snakes

48. 1.8 With hypothesis-based science, we pose and test hypotheses Non-poisonous snakes that mimic coloration of coral snakes are attacked less frequently Control group- brown snake (non-threatening) Experimental group- artificial snakes with the red, black, and yellow ring pattern of king snakes Copyright © 2009 Pearson Education, Inc.

49. Scientific testing can include assumptions: What might some assumptions of this study be? 1.Predators cannot tell a scarlet from a king snake 2.Predators would be interested in the brown snake

52. Artificial king snakes Artificial brown snakes 100 Coral snakes absent Coral snakes present Percent of total attacks on artificial snakes 83% 20 40 84% 16% 0 17% 60 80 Y-axis (dependent variable) (i.e. The data depends on what the experimental variables are) X-axis (independent variable) (i.e. What the researcher chooses to test; the experimental variables)

53. Artificial king snakes Artificial brown snakes 100 Coral snakes absent Coral snakes present Percent of total attacks on artificial snakes 83% 20 40 84% 16% 0 17% 60 80

55. BIOLOGY AND EVERYDAY LIFE Copyright © 2009 Pearson Education, Inc. 1.9 Biology, technology, and society are connected in important ways

56. Many of today’s global issues relate to biology (science) Many of these issues resulted from applications of technology Science and technology are interdependent, but their goals differ Science wants to understand natural phenomena Technology applies science for a specific purpose Copyright © 2009 Pearson Education, Inc.

57. 1.10 EVOLUTION CONNECTION: Evolution is connected to our everyday lives How is evolution connected to our everyday lives? It explains how all living species descended from ancestral species –Differences between DNA of individuals, species, and populations reflect evolutionary change The environment matters because it is a selective force that drives evolution An understanding of evolution helps us fight disease and develop conservation efforts Copyright © 2009 Pearson Education, Inc.

58. You should now be able to 1.Describe life’s hierarchy of organization 2.Describe living organisms’ interactions with their environments 3.Describe the structural and functional aspects of cells 4.Explain how the theory of evolution accounts for the unity and diversity of life 5.Distinguish between discovery science and hypothesis-based science 6.Describe ways in which biology, technology, and society are connected Copyright © 2009 Pearson Education, Inc.

60. has changed through the process of Biology is the study of (a) mechanism is (b) accounts for depends on DNA (genetic code) accounts for (d) codes for is evidence of seen in variations in seen in common properties of living organisms cells as basic units of life diversity of life (e) seen in leads to (c)

61. In this experiment, mice learn to run through a maze. Based on the graph, what is the hypothesis the researchers were testing?

62. Concept Check Darwin proposed the theory of natural selection. For the most part, natural selection acts as a filtering agent at the ___________level of life’s hierarchy. – Community – Population – Individual – Organ

63. Answer Darwin proposed the theory of natural selection. For the most part, natural selection acts as a filtering agent at the ___________level of life’s hierarchy. 2)Population

64. Concept Check Not all scientific discoveries are reached through the “scientific method.” Which of the following would best be described as discovery science? – Looking for a live specimen of an organism found in the fossil record. – Describing a new bird species from the Philippines. – A project to find preserved specimens of the probably extinct Rocky Mountain locust frozen in glaciers. – All of the above.

65. Answer Not all scientific discoveries are reached through the “scientific method.” Which of the following would best be described as discovery science? 4)All of the above.

66. Interpreting Data These two snakes look remarkably similar to each other. The coral snake (right) is very poisonous to vertebrates. Hypotheses: H 1 : The coral snake’s bright color pattern serves to warn off potential predators. H 2 : The the king snake suffers less predation because it mimics or looks like the coral snake. H 3 : The protection that king snakes receive by mimicking coral snake will depend on the presence of coral snakes.

67. Interpreting Data A team of scientists designed an investigation that used artificial snakes to test the previous hypotheses. Which of the previous hypotheses are supported by the results displayed at the right? 1)H 1 : The coral snake’s bright color pattern serves to warn off potential predators. 2)H 2 : The the king snake suffers less predation because it mimics or looks like the coral snake. 3)H 3 : The protection that king snakes receive by mimicking coral snake will depend on the presence of coral snakes. 4)Both 2 and 3

68. Answer A team of scientists designed an investigation that used artificial snakes to test the previous hypotheses. Which of the previous hypotheses are supported by the results displayed at the right? 4)Both 2 and 3

69. Interpreting Data Biologists placed artificial snake mimics in two different localities to test the hypothesis that looking like a poisonous snake only works where the poisonous snake is found: 1. Outside of the coral snake range—only king snakes present. 2. Inside the coral snake range— both coral and king snakes are present.

70. Interpreting Data The data graphed at the right __________ the hypothesis that the effectiveness of mimic coloration depends upon the presence of the poisonous model is: – supports – does not support – is irrelevant to

71. Answer The data graphed at the right __________ the hypothesis that the effectiveness of mimic coloration depends upon the presence of the poisonous model is: – supports

72. Interpreting Data Based on this data which of the following is a logical hypothesis or prediction? – King snakes outside of the range of coral snakes will more closely resemble coral snakes than populations of king snake living within the range of coral. – King snakes outside of the range of coral snakes will not resemble coral snakes as closely as populations of king snakes that live within the range coral snakes. – Neither prediction is valid.

73. Answer Based on this data which of the following is a logical hypothesis or prediction? 2)King snakes outside of the range of coral snakes will not resemble coral snakes as closely as populations of king snakes that live within the range coral snakes.

74. Biology and Society Even a cursory glance at the news media reveals that scientific progress is an essential part of modern society. Still, many people are very skeptical of science. Do you think that an informed citizen needs a firm foundation of understanding of science to effectively participate in a representative society? Disagree Agree Strongly A B C D E Strongly

75. Biology and Society Even a cursory glance at the news media reveals that scientific progress is an essential part of modern society. Still, many people are very skeptical of science. Do you think that scientists should take a more active role in helping society to understand and apply their findings? Disagree Agree Strongly A B C D E Strongly

76. Biology and Society Religion and science are often at odds. Some feel that religion and science are two powerful but separate ways of human understanding. Most importantly these people do not feel that science and religion are in conflict. Do you think that an individual can hold devout religious beliefs, while at the same time support scientific understanding? Disagree Agree Strongly A B C D E Strongly

77. Isn’t evolution just a theory? http://www.youtube.com/watch?v=85diEX bJBIk How does evolution really work? http://www.youtube.com/watch?v=Pf9P0lr pgLk