Jerry

CHAPTER 1 Outline: An Introduction to Life on Earth

1.1 How Do Scientists Study Life?

A. Life Can Be Studied at Different Levels (Figures 1-1 and 1-2)

1. Living things are composed of atoms

a. Atoms—smallest particles of elements

B. Scientific Principles Underlie All Scientific Inquiry

1. Natural causality is the principle that all events can be traced to natural causes

2. Natural laws apply to every time and place

3. Scientific inquiry is based on the assumption that people perceive natural events in similar

ways (Figure 1-3)

C. The Scientific Method Is the Basis for Scientific Inquiry

1. The scientific method includes a number of steps (Figure 1-4)

a. Observation—observe a phenomenon

b. Question—form a question about the phenomenon

c. Hypothesis—supposition based on previous observations that is offered as an

explanation

d. Prediction—typically expressed in “if…then…” language

e. Experiment—designed to test hypotheses

f. Conclusion—can be drawn on the basis of results of experiments?

2. Variables are factors that may affect the outcome of an experiment

3. Controls are control variables so that they remain constant?

D. Communication Is Crucial to Science

E. Science Is a Human Endeavor (Figure 1-5)

F. Scientific Theories Have Been Thoroughly Tested

1. Scientific theory is an explanation of natural phenomena developed through extensive and

reproducible observations

2. Science is based on reasoning

a. Inductive reasoning—process of creating a generalization as a result of making many

observations that support it and none that contradict it

b. Deductive reasoning—generating a hypothesis based on well-accepted scientific theory

3. Scientific theories are formulated in ways that can be potentially disproved

1.2 Evolution: The Unifying Theory of Biology

A. Three Natural Processes Underlie Evolution (Figures 1-6 and 1-7)

1. Genetic variability among organisms is inherited

a. Genetic variation—differences in DNA

b. Inheritance of...