1. Essentials of the Living World
Second Edition
George B. Johnson
Jonathan B. Losos
Chapter 1
The Science of Biology
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

2. 1.1 The Diversity of Life Biology is the study of living things
Living things are diverse
There are enough similarities among some living things that they can be grouped into the same kingdom
Members of different kingdoms are usually very different from each other
Point out the text is appropriately titled, The Living World

3. The Six Kingdoms of Life Figure 1.1

4. 1.2 Properties of Life
What qualifies something as “living” versus “non-living?”
Consider these points
complexity
movement
response to stimulation
A life-defining property must be exclusive to living things
Prompt students to decide what properties the living things in the kingdoms have? Are those properties exclusive to living things? What properties are?

5. 1.2 Basic Properties of Life
1. Cellular organization
all living things are comprised of at least one cell
2. Metabolism
all living things process energy which is used to power other processes
3. Homeostasis
all living things maintain stable internal environments to optimize conditions for metabolism and other processes
All organisms share 5 properties that are unique to life.

6. 1.2 Basic Properties of Life
4. Growth and reproduction
all organisms have the capacity for growth and reproduction
5. Heredity
all organisms pass genetic information across generations from parents to offspring

7. 1.3 The Organization of Life
Living things function and interact with each other on many levels
The organization of life is a hierarchy of levels of increasing complexity
cellular
organismal
populational
The following slide sequence shows the hierarchy of transitions from one level of complexity to the next—emphasize the interconnectedness.

8. Fig. 1.4 Cellular Level

9. Fig. 1.4 Organismal Level

10. Fig. 1.4 Population Level

11. 1.3 The Organization of Life
At higher levels of the living hierarchy, new properties become apparent that were absent at the lower levels
These emergent properties result from the interaction of diverse but simpler components
Many higher order processes that are hallmarks of life are emergent properties
metabolism
consciousness

12. 1.4 Biological Themes
The study of life is organized around general themes
5 biological themes emerge repeatedly at any hierarchical level of biological study
refer to Table 1.1

13. 1.4 Biological Themes 1. Evolution
evolution is genetic change in a species over time
the mechanism for evolution is natural selection
the diversity of life is explained by evolutionary processes

14. 1.4 Biological Themes 2. The Flow of Energy
all living things require energy
energy from the sun flows through the living world
organisms acquire energy differently
how much energy is available determines how many and what kinds of organisms can live together in an ecosystem

15. 1.4 Biological Themes 3. Cooperation
as energy and other resources are limiting, many organisms have evolved cooperation as a means of survival
symbiosis describes when two species live in direct contact

16. 1.4 Biological Themes 4. Structure Determines Function
evolution favors structures that function in an adaptive manner
many structures are specialized for a particular function
the convergence of structure and function occurs at levels of the organizational hierarchy

17. 1.4 Biological Themes 5. Homeostasis
homeostasis is a physiological condition of “steady-state”
the internal environment of organisms is remarkably stable
organisms act to control their internal environments so that the complex processes of metabolism function efficiently

18. 1.5 How Scientists Think
Science is a process of investigation, using observation, experimentation, and reasoning
There are different philosophical approaches to reasoning
May mention that a Ph.D. is actually a doctorate of philosophy.

19. 1.5 How Scientists Think
Deductive reasoning uses general principles to explain specific observations
This form of reasoning is common to many disciplines, including
mathematical proofs
politics
computing

20. 1.5 How Scientists Think
Inductive reasoning is the way of discovering general principles from examination of specific observations
Scientists employ inductive reasoning by forming and testing possible explanations for specific observations
These possible explanations are called hypotheses

21. Figure 1.5 Deductive and inductive reasoning
Compare and contrast the two forms of reasoning and emphasize which one is more scientific.

22. 1.6 Science in Action: A Case Study
Scientist Joseph Farman observed in 1985 that ozone levels in Anarctica are alarmingly low
Pollution by chloroflourocarbons (CFCs) was later found to be the culprit
CFCs were common components of many synthetic products, such as
coolants used in air conditioners
propellants in aerosols
foaming agents in Styrofoam

23. Figure 1.6 How CFCs attack and destroy ozone

24. 1.6 Science in Action: A Case Study
Ozone depletion is a serious matter
ozone acts as a sunscreen against ultraviolet rays from the sun
a 1% drop in ozone leads to a 6% increase in skin cancer
A world-wide reduction in CFC production has helped alleviate ozone depletion

25. 1.7 Stages of a Scientific Investigation
Biology is a dynamic science with new ideas appearing and replacing old ones
Scientists systematically conduct experiments to evaluate hypotheses about observed phenomena

26. 1.7 Stages of a Scientific Investigation
The scientific process has six stages
1. Observation
science begins with careful observation of natural phenomena
2. Hypothesis
scientists make an educated guess that might be true
often scientists formulate multiple ideas about a phenomenon; these are called alternative hypotheses

27. 1.7 Stages of a Scientific Investigation
3. Predictions
if a hypothesis is correct, then specific consequences can be expected
4. Testing
scientists conduct experiments to attempt to verify predictions made by hypotheses

28. 1.7 Stages of a Scientific Investigation
5. Controls
experiments usually employ a parallel design
scientists use a control to assess the influence of potential factors, called variables
conditions stay the same in the control in comparison to the variable condition
6. Conclusion
a hypothesis that has been tested and not rejected is tentatively accepted
Most experiments lead to future experiments!

29. Fig.1.7 The scientific process

30. 1.7 Stages of a Scientific Investigation
Scientific research involves analyzing data before reaching any conclusion
Scientists must present their results carefully so that others can interpret them

31. 1.8 Theory and Certainty
The term “theory” means different things to different audiences
to scientists,
a theory represents certainty and is a unifying explanation for a broad range of observations
to the general public,
a theory implies a lack of knowledge or guess

32. 1.8 Theory and Certainty
Scientists’ acceptance of theory is provisional
the possibility always remains that future evidence will cause a theory to be revised
The process of science is not just trial-and-error but involves judgement and intuition

33. 1.8 Theory and Certainty science has limitations
it is limited to organisms and processes that can be observed and measured
supernatural and religious phenomena are beyond the scope of science
there are also practical limits
science cannot be relied upon to solve all problems

34. 1.9 Four Theories Unify Biology as a Science
1. The Cell Theory
2. The Gene Theory
3. The Theory of Heredity
4. The Theory of Evolution

35. The Cell Theory all organisms are composed of at least one cell
the cell is the most basic unit of life
all cells come from pre-existing cells

36. The Gene Theory
genetic information is encoded in molecules of deoxyribonucleic acid (DNA)
genes encode specific proteins or RNA or act to regulate other genes
the proteins and RNA encoded by an organism’s genes determine what it will be like in terms of form and function

37. Figure 1.12 The gene theory

38. The Theory of Heredity
genes are passed down generations as discrete units
Mendel’s theory of heredity gave rise to the field of genetics
chromosomal theory of inheritance located Mendelian genes on chromosomes

39. The Theory of Evolution
Charles Darwin’s theory of evolution explains the unity and diversity of life as “descent with modification”
All living organisms are related to one another in a common tree of descent

40. Fig The tree of life

41. Classifying Life’s Diversity
Scientists group organisms, based on similarities, into six kingdoms
Each of the six kingdoms are assigned, on the basis of cell structure into one of three domains

42. Figure 1.16 The three domains of life

43. Inquiry & Analysis What is the dependent variable?
Is the size of the ozone hole increasing?
Why are the rates of increase different between and ?
Insert figure of History of the Ozone Hole: Peak Size