Transcript CHAPTER ONE The Science of Biology Created by Lynn Collins (April, 2013) 1-1 What is Science? SC.912.N.2.1 Key Questions What are the goals of science? What procedures.

CHAPTER ONE
The Science of Biology
Created by Lynn Collins (April,
2013)
1-1 What is Science?
SC.912.N.2.1
Key Questions
What are the goals of science?
What procedures are at the core of scientific
methodology?
VOCABULARY
Science
Observation
Inference
Controlled experiment
Independent variable
Dependent variable
Control group
Hypothesis
Data
What Science Is and Is Not
Science as a Way of Knowing
Science is an organized way of gathering
and analyzing evidence about the natural
world. It is a process, not a “thing.”
1. Science deals only with the natural
world.
Whale Researchers
2. Scientific endeavors never concern, in any
way, supernatural phenomena of any kind.
• Scientists collect and organize information
in an orderly way, looking for patterns and
connections among events.
• 3. Scientists propose explanations that
are based on evidence, not belief.
Then they test those explanations with more
evidence!
The Goals of Science
•From a scientific perspective all objects in the
universe, and all interactions among those objects, are
governed by universal natural laws…no matter whether
the events are large or small.
• KEY: One goal of science is to provide
natural explanations for events in the
natural world.
• Science aims to use those explanations to
understand patterns in nature and to make
useful predictions about natural events.
For example…Hurricane Sandy
Science helps us…cure diseases
Science helps us…place satellites
in orbit
Science helps us…send
instantaneous electronic
communications
Despite all we know, much of science
remains a mystery???????????????
Learning science means more than just
understanding what we know. It also
means understanding what we don’t know.
Science rarely proves anything in absolute
terms.
Build Vocabulary
WORD ORIGINS: The word science
derives from the Latin word scienitia,
which means “knowledge.” Science
represents knowledge that has been
gathered over time.
Scientific Methodology: The Heart
of Science
• What procedures are at the core of
scientific methodology?
• You might think that the procedures are a
mystery. Not so! You use scientific
thinking all the time…
Suppose your family’s car won’t
start. What do you do?
There isn’t a single cut-and-dried
“scientific method”
There is however, a general style of investigation
that we call scientific methodology.
Scientific methodology involves:
• observing and asking questions,
• making inferences and forming hypotheses,
• conducting controlled experiments,
• collecting and analyzing data,
• drawing conclusions.
Salt Marsh Experiment
Observing and Asking Questions
Observation – the act of noticing and
describing events or processes in a
careful, orderly way.
Arthur Schopenhauer
“A good scientist can
think something that
nobody has thought
yet, while looking at
something that everybody sees.”
Inferring and Forming a Hypothesis
An inference is a logical interpretation
based on what scientists already know.
Inference combined with a creative
imagination, can lead to a hypothesis.
Hypothesis is a scientific explanation for a
set of observations that can be tested in
ways that support or reject it.
DO NOT SAY THAT AN HYPOTHESIS IS
AN EDUCATED GUESS!!!!!
Designing Controlled Experiments
Testing a scientific hypothesis often involves
designing an experiment that keeps tract of
various factors that can change, or variables.
(examples: temperature, light, time, availability
of nutrients)
Whenever possible a hypothesis should be tested
by an experiment where only one variable is
changed. All other variable should be kept
unchanged or controlled. This type of
experiment is called a controlled experiment.
Controlling variables
• Independent Variable (also called the
Manipulated variable) –the variable that
you, the experimenter, changes in order to
do your experiment.
• (In our example, the nitrogen fertilizer was
the independent variable)
• Dependent Variable (also called the
Responding variable) – the variable
changes when the independent variable
changes – it depends on the outcome of
the independent variable.
• (In the example – growth of the marsh
grass)
Control and Experimental Groups
Typically an experiment is divided into control and
experimental groups.
A control group is exposed to the same
conditions as the experimental group except for
one independent variable.
Scientists try to replicate their experiments, so they
set up several sets of control and experimental
groups.
Collecting and Analyzing Data
Scientists make detailed records of
experimental observations, gathering
information called data.
Quantitative data – numbers obtained by
counting
Qualitative data – characteristics that
usually cannot be counted
Research Tools
Scientists choose appropriate tools for
collecting and analyzing data. Tools may
be as simple as a meter stick or as
complicated as machines that can
measure the nitrogen content in plants and
soil.
Today, computers play a huge role in
collecting, organizing, analyzing data.
Sources of Error
Researchers must be careful to avoid errors
in data collection and analysis.
Drawing Conclusions
When Experiments Are Not
Possible
Natural animal behavior may require field
observations that disturb the animals as little as
possible. Whey researchers analyze data from
these observations, they may devise hypotheses
that can be tested in different ways.
Sometimes ethics prevents certain types of
experiments – especially on human subjects.