Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. BIOLOGY A GUIDE TO THE NATURAL WORLD FOURTH EDITION DAVID KROGH Science as a way of learning: A Guide to the Natural World

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.1 How Does Science Impact the Everyday World?

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. 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. More organisms are being genetically modified and cloned. Global warming affects many aspects of our lives

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. What Do Americans Know About Science? Figure 1.3 Early humans did not coexist with dinosaurs. Antibiotics kill bacteria but not viruses. The father’s gene determines the sex of a child. The Earth goes around the sun. The oxygen we breathe comes from plants. 48% 51% 65% 75% 79% 87% Percent of Americans who understand that: Continents are moving on the Earth’s surface.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.2 What is Science?

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Science as a Body of Knowledge Figure 1.4 Observation Question Hypothesis Experiment Conclusion

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Science as Process An example of hypothesis testing is Louis Pasteur’s experiment regarding the spontaneous generation of life

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. When you start with a sterile flask of sterile meat broth... Observation Question: What is the source of the living material? Pasteur’s experiments: Conclusion: No growth appears in the broth unless dust is admitted from outside. Reject “spontaneous generation” hypothesis. Hypothesis:... a growth of new living material generally appears in the broth. The living material is derived from nonliving material (spontaneous generation). sterile flask Particle trap sterile broth dust trapped in neck of flask remove trap no growth growth tip flask to mix trapped dust into broth Hypothesis 1Hypothesis 2 The living material is derived from living material outside of the flask. growth of new material in broth sterile flask sterile broth Scientific method at work: Pasteur tests “spontaneous generation” Science as Process Figure 1.5

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Science as Process In science, every assertion regarding the natural world is subject to challenge and revision.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1. A hypothesis is an idea that is widely accepted as a description of objective reality by a majority of scientists. 2. A hypothesis must stand alone, and not be based on prior knowledge. 3. A hypothesis must be testable through experimentation, observation, or mathematical demonstration. 4. A hypothesis is the same as an observation. For any scientific question there is only one hypothesis tested. Which of the following statements best describes the nature of a scientific hypothesis? Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.varied the bacteria he employed with each experiment 2.varied the temperature to which he initially heated the flasks 3.observed the bacteria as they were growing in the flasks 4.held all conditions constant in each test except one 5.was willing to vary to the extent necessary from the standard hypotheses of his day Pasteur's experiments on spontaneous generation made correct use of a variable in that Past Pasteur's experiments on spontaneous generation made correct use of a variable in that Pasteur eur Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.3 The Nature of Biology

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. The Nature of Biology Biology is the study of life.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things Life is defined by a group of eight characteristics possessed by living things.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 1. Assimilate energy.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 2. Respond to their environment.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 3. Maintain a relatively constant internal environment.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 4. Reproduce.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 5. Possess an inherited information base, encoded in DNA, that allows them to function.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 6. Are composed of one or more cells.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 7. Are evolved from other living things.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Characteristics of Living Things 8. Are highly organized compared to inanimate objects.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.All living things possess an inherited information base, encoded in DNA, that allows them to function. 2.All living things can respond to their environment. 3.All living things can take in and use energy. 4.All living things evolved from other living things. 5.All living things are composed of two or more cells. Biolo Biologists generally define life in terms of a group of characteristics possessed by living things. Which of the following is not a characteristic of living things? gists generally define life in terms of a group of characteristics possessed by livings. Which of the following is not a characteristic of living things? Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Biologists generally define life in terms of a group of characteristics possessed by living things. Which of the following is not a characteristic of living things?

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Life is Hierarchical Figure 1.6 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)

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.4 Special Qualities of Biology

Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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).

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 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.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Biology’s Chief Unifying Principle Evolution provides the means for making sense of the forms and processes seen in living things on Earth today.

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Biology’s Chief Unifying Principle Figure 1.7

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Biology’s Chief Unifying Principle Many stinging insects with black and yellow stripes look alike because of the general protection this provides from predators

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. Biology’s Chief Unifying Principle Figure 1.8

Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings. 1.It is not a falsifiable hypothesis. 2.Humans have evolved from ancestors we share with present-day monkeys. 3.It has occurred in the past, even though it no longer operates today. 4.The enormously diverse forms of life on Earth have all been shaped by it. 5.Almost all biologists believe in it. Evolution is a central, unifying theme in biology because Copyright © 2009 Pearson Education, Inc., publishing as Benjamin Cummings. Evolution is a central, unifying theme in biology because