1. A Guide to the Natural World David Krogh © 2011 Pearson Education, Inc. Chapter 1 Lecture Outline Science as a Way of Learning: A Guide to the Natural World Biology Fifth Edition

2. © 2011 Pearson Education, Inc. 1.1 How Does Science Impact the Everyday World?

3. © 2011 Pearson Education, Inc. How Does Science Impact the Everyday World? Science plays an increasingly important role in the everyday lives of Americans. Until the mid-1990s, most Americans did not use e-mail, cell phones, or the Internet.

4. © 2011 Pearson Education, Inc. What Do Americans Know About Science? Figure 1.1

5. © 2011 Pearson Education, Inc. What Do Americans Know About Science? The average American has at best an uneven knowledge of science.

6. © 2011 Pearson Education, Inc. What Do Americans Know About Science? Almost 80 percent of adult Americans who were surveyed know that the continents are moving about the face of the Earth. Of those surveyed, 25 percent think the sun goes around the Earth.

7. © 2011 Pearson Education, Inc. 1.2 What Is Science?

8. © 2011 Pearson Education, Inc. What Is Science? Science is a body of knowledge; a collection of unified insights about nature, the evidence for which is an array of facts.

9. © 2011 Pearson Education, Inc. Science as a Body of Knowledge The unified insights of science are known as theories. A theory is a general set of principles, supported by evidence, that explains some aspect of nature.

10. © 2011 Pearson Education, Inc. Science as a Body of Knowledge Science can also be defined as a way of learning; a process of coming to understand the natural world through observation and the testing of hypotheses.

11. © 2011 Pearson Education, Inc. Science as a Body of Knowledge Figure 1.3

12. © 2011 Pearson Education, Inc. Science as a Body of Knowledge Science works through the scientific method, in which an observation leads to the formulation of a question about the natural world.

13. © 2011 Pearson Education, Inc. Science as a Body of Knowledge Science is a tentative, testable explanation that has not been proven true. The hypothesis may be tested through observation or through a series of experiments, as aided by statistical procedures.

14. © 2011 Pearson Education, Inc. Science as Process An example of hypothesis testing is Louis Pasteur’s experiment regarding the spontaneous generation of life

15. © 2011 Pearson Education, Inc. Figure 1.4 Scientific method at work: Pasteur tests “spontaneous generation” Observation: sterile flask sterile broth When you start with a sterile flask of sterile meat broth... Question: What is the source of the living material? Hypothesis: Hypothesis 1 The living material is derived from nonliving material (spontaneous generation). Pasteur's experiments: sterile flask particle trap dust trapped in neck of flask no growth sterile broth tip flask to mix trapped dust into broth Conclusion: No growth appears in the broth unless dust is admitted from outside. Reject “spontaneous generation” hypothesis. growth remove trap The living material is derived from living material outside the flask. Hypothesis 2 growth of new material in broth... a growth of new living material generally appears in the broth.

16. © 2011 Pearson Education, Inc. Science as Process In science, every assertion regarding the natural world is subject to challenge and revision.

17. © 2011 Pearson Education, Inc. When Is a Theory Proven? Scientific claims must be falsifiable, meaning open to negation through scientific inquiry Scientific inquiry is limited to investigating natural (as opposed to supernatural) explanations for natural phenomena.

18. © 2011 Pearson Education, Inc. When Is a Theory Proven? Animation 1.1 Scientific Method

19. © 2011 Pearson Education, Inc. 1.3 The Nature of Biology

20. © 2011 Pearson Education, Inc. The Nature of Biology Biology is the study of life.

21. © 2011 Pearson Education, Inc. Characteristics of Living Things Life is defined by a group of eight characteristics possessed by living things.

22. © 2011 Pearson Education, Inc. Characteristics of Living Things 1. Assimilate energy.

23. © 2011 Pearson Education, Inc. Characteristics of Living Things 2. Respond to their environment.

24. © 2011 Pearson Education, Inc. Characteristics of Living Things 3. Maintain a relatively constant internal environment.

25. © 2011 Pearson Education, Inc. Characteristics of Living Things 4. Reproduce.

26. © 2011 Pearson Education, Inc. Characteristics of Living Things 5. Possess an inherited information base, encoded in DNA, that allows them to function.

27. © 2011 Pearson Education, Inc. Characteristics of Living Things 6. Are composed of one or more cells.

28. © 2011 Pearson Education, Inc. Characteristics of Living Things 7. Are evolved from other living things.

29. © 2011 Pearson Education, Inc. Characteristics of Living Things 8. Are highly organized compared to inanimate objects.

30. © 2011 Pearson Education, Inc. Life Is Hierarchical Life is organized in a hierarchical manner, ranging in increasing complexity from atoms to molecules to organelles, cells, tissues, organs, organ systems, organisms, populations, communities, ecosystems, and the biosphere.

31. © 2011 Pearson Education, Inc. Life Is Hierarchical Figure 1.5 atom (hydrogen) molecule (water) organelle (nucleus) cell (neuron) tissue (nervous tissue) organ (brain) organ system (nervous system) organism (sea lion) population (colony) community (giant kelp forest) ecosystem (Southern California coast) biosphere (Earth)

32. © 2011 Pearson Education, Inc. 1.4 Special Qualities of Biology

33. © 2011 Pearson Education, Inc. Special Qualities of Biology Until the early nineteenth century, biology was largely a descriptive science that mainly catalogued and described the Earth’s living things.

34. © 2011 Pearson Education, Inc. Special Qualities of Biology Biology’s subject matter—the living world—is notable for its complexity and diversity compared to other aspects of the natural world (such as stars and atoms).

35. © 2011 Pearson Education, Inc. Special Qualities of Biology Biology does not deal in universal rules to the extent that a discipline such as physics does; instead, biological research may focus on particular species, processes, or portions of the living world.

36. © 2011 Pearson Education, Inc. Biology’s Chief Unifying Principle Biology’s chief unifying principle is evolution, which can be defined as the gradual modification of populations of living things over time. This modification sometimes results in the development of new species.

37. © 2011 Pearson Education, Inc. Biology’s Chief Unifying Principle Evolution provides the means for making sense of the forms and processes seen in living things on Earth today.

38. © 2011 Pearson Education, Inc. Biology’s Chief Unifying Principle Figure 1.6

39. © 2011 Pearson Education, Inc. Biology’s Chief Unifying Principle Many stinging insects with black and yellow stripes look alike because of the general protection this provides from predators.

40. © 2011 Pearson Education, Inc. Biology’s Chief Unifying Principle Figure 1.7