An Introduction to the Science of Biology
What is Science
And
How are we to Use it Correctly?
An Introduction to the Science of
Biology
What is Science?
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Science is a tool we use to help
us understand the world around
us
Biology is one of the sciences
that deals with the study of
living things
Like any other tool science has
an “instruction book” that spells
out how to properly use science
We call this “instruction book”
the scientific method
Scientific Method
How can the scientific method help us
understand living things?
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Biology, like other sciences, often starts
with observations
These observations
questions
often
lead
to
Scientists pose a possible explanation to
answer their question.
The scientific method provides specific
steps to help scientists determine if their
proposed explanation has any merit in
answering their question about what they
have observed
Let’s study the steps involved in the
scientific method
Scientific Method
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Steps in the Scientific
Method (Overview)
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Observations
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Development of Questions
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Hypothesis
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Controlled Experiment
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Analysis of Data
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Conclusions
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Sharing Results
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Reformulation of Hypothesis, if
needed
Scientific Method
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Scientific Method
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Observations and the
development of
questions
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Noticing something
about our natural world
Having the curiosity to
ask questions
Questions lead to an
hypothesis
Scientific Method
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Scientific Method
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Hypothesis
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An educated guess about
how some observable
condition in the natural world
occurs
Based, in part, on what was
observed
What else could play a role in
an observer developing an
hypothesis?
An hypothesis is tested by
experimentation
Scientific Method
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Scientific Method
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Controlled Experiment
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“Controlled” because a control-a
part of the experiment that does
not change-is used
Remove all the variables except
the one variable you want to
test
Variables are those things in a
scientific experiment that can
change
“Double blind” studies help to
reduce the experimenter's bias
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Placebos
Scientific Method
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Scientific Method
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Analyze the Data
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Statistics: method commonly
used to evaluate data
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Statistical Significance
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Standard error tells us how
uncertain a particular piece of
data is
Used to help determine how
probable the experimental
results were due to chance alone
Data is often depicted in graph
form (bar graphs, line graphs,
etc)
Scientific Method
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Scientific Method
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Conclusions
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Interpretations of the
data, and only the
data, gathered during
the experiment
Conclusions either
support the hypothesis
or they do not!
Scientific Method
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Scientific Method
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Share Results
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To reduce chance and
bias the experiment
MUST be repeated by
others to see if the
conclusions of these
others are the same as
the original
experimenter or not
Scientific Method
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Scientific Method
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Share Results
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If the conclusions do
not support the original
hypothesis then the
hypothesis needs to
be reformulated and
retested
Scientific Method
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Scientific Method
–
Share Results
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If the conclusions do
support the original
hypothesis after many
experiments
conducted by
different scientists
then a theory generally
develops
Scientific Method
A scientific theory
represents an hypothesis,
or a group of related
hypotheses, which has
been supported through
repeated experimental tests
and which helps explains
something about our
natural world.
Scientific Method
Science NEVER proves ANYTHING about our
natural world!
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The scientific method relies on deductive
reasoning
Scientific hypotheses and theories therefore
have deductive consequences
SO...
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Hypotheses and theories must be “falsifiable”.
That is, hypotheses and theories must be
allowed to be shown false by a particular
observation or physical experiment.
If an hypothesis or theory is not falsifiable then
it is NOT considered scientific.
Themes & Concepts in Biology
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Characteristics of Life
Organization of Living Things
Characteristics of Life
So how do you define life?
Science recognizes that living things share key
characteristics and/or functions
Characteristics of Life
1. Living things are
organized
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Hierarchy of
organization for less to
more complex
Cell is the smallest
functional unit in living
things. (Or is it?)
Characteristics of Life
1. Living things are
organized
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Biological organization
extends beyond the
individual
Characteristics of Life
2. Living things acquire materials
& energy
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Animals acquire materials &
energy from the foods they eat
Plants usually acquire their
materials & energy from the soil
and from sunlight
These materials & energy are
used to carry on life's activities.
What are those activities?
Ultimate source of energy for all
life on this planet is the sun
Characteristics of Life
3. Living things demonstrate
homeostasis
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Homeostasis: the dynamic
maintenance of the internal
environment of an animal
Name some conditions that
your body maintains
Humans generally maintain
homeostasis via negative
feedback loops
Characteristics of Life
4. Living things respond
to stimuli
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Response may be
external or internal
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Allows for homeostasis
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Examples?
Bear?
Characteristics of Life
5. Living things reproduce
& develop
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Cells reproduce cells
Animals reproduce
animals
Plants reproduce plants
Development involves
growth & changes in form
directed by DNA
Characteristics of Life
6. Living things adapt
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Response to changing stimuli
for the purpose of
homeostasis
Example of the snow hare
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In warmer months coat is darker
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In colder months coat is lighter
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What is the hare adapting to?
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What other characteristic(s) of
living things would this
adaptation provide for?
Discussion Question of the Week
If science is a “tool” to help us understand the
world around us what other “tools” exist and
how to they work to also help us understand the
world around us?