Science as a way of learning: A Guide to the Natural World

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Science as a way of learningA Guide to the
Natural World
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1.1 How Does Science Impact theEveryday World?
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How Does Science Impact theEveryday 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.

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What Do Americans Know About Science?
Figure 1.1
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What Do Americans Know About Science?

• The average American has at best an uneven
  knowledge of science.

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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.

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What Do Americans Know About Science?
Percent of Americans who understand that
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Early humans did not coexist with dinosaurs.
Antibiotics kill bacteria but not viruses.
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The fathers gene determines the sex of a child.
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75
The Earth goes around the sun.
Continents are moving on the Earths surface.
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The oxygen we breathe comes from plants.
Figure 1.3
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1.2 What is Science?
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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.

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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.

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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.

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Science as a Body of Knowledge
Observation
Question
Hypothesis
Experiment
Conclusion
Figure 1.4
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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.

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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.

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Science as Process

• An example of hypothesis testing is Louis
  Pasteurs experiment regarding the spontaneous
  generation of life

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Science as Process
Scientific method at work Pasteur tests
spontaneous generation
Observation
growth of new material in broth
sterile flask
sterile broth
When you start with a sterile flask of sterile
meat broth. . .
. . . a growth of new living material generally
appears in the broth.
Question What is the source of the living
material?
Hypothesis
Hypothesis 1
Hypothesis 2
The living material is derived from
nonliving material (spontaneous generation).
The living material is derived from living
material outside of the flask.
Pasteurs experiments
remove trap
dust trapped in neck of flask
sterile flask
growth
Particle trap
no growth
sterile broth
growth
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.
Figure 1.5
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Science as Process

• In science, every assertion regarding the natural
  world is subject to challenge and revision.

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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.

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When is a Theory Proven?
PLAY
Animation 1.1 Scientific Method
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1.3 The Nature of Biology
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The Nature of Biology

• Biology is the study of life.

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Characteristics of Living Things

• Life is defined by a group of eight
  characteristics possessed by living things.

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Characteristics of Living Things

• 1. Assimilate energy.

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Characteristics of Living Things

• 2. Respond to their environment.

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Characteristics of Living Things

• 3. Maintain a relatively constant internal
  environment.

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Characteristics of Living Things

• 4. Reproduce.

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Characteristics of Living Things

• 5. Possess an inherited information base, encoded
  in DNA, that allows them to function.

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Characteristics of Living Things

• 6. Are composed of one or more cells.

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Characteristics of Living Things

• 7. Are evolved from other living things.

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Characteristics of Living Things

• 8. Are highly organized compared to inanimate
  objects.

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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.

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Life is Hierarchical
atom(hydrogen
Molecule(water)
organelle(nucleus)
cell(neuron)
tissue(nervous tissue)
organ(brain)
organ system(nervous system)
organism(sea lion)
population(colony)
community(giant kelpforest)
ecosystem(southern Californiacoast)
biosphere(Earth)
Figure 1.6
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1.4 Special Qualities of Biology
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Special Qualities of Biology

• Until the early nineteenth century, biology was
  largely a descriptive science that mainly
  catalogued and described the Earths living
  things.

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Special Qualities of Biology

• Biologys subject matterthe living worldis
  notable for its complexity and diversity compared
  to other aspects of the natural world (such as
  stars and atoms).

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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.

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Biologys Chief Unifying Principle

• Biologys 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.

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Biologys Chief Unifying Principle

• Evolution provides the means for making sense of
  the forms and processes seen in living things on
  Earth today.

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Biologys Chief Unifying Principle
Figure 1.7
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Biologys Chief Unifying Principle

• Many stinging insects with black and yellow
  stripes look alike because of the general
  protection this provides from predators

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Biologys Chief Unifying Principle
Figure 1.8