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Biology and the Scientific Method . Chapter One. What is science?. Goal of Science. to investigate and understand nature and to use those explanations to make useful predictions What are some examples of science? What advances have occurred because of science?. Limitations of Science.
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Biology and the Scientific Method Chapter One
Goal of Science • to investigate and understand nature and to use those explanations to make useful predictions • What are some examples of science? • What advances have occurred because of science?
Limitations of Science • Science cannot explain everything!! • Science does not attempt to explain religion or philosophy. • Science deals with logic, not values.
The Scientific Method An organized approach to solving problems using science. Steps will vary from one book to another.
Step One • IDENTIFY THE PROBLEM
Step Two • Form a hypothesis. • Hypothesis • an explanation to a set of observations or a possible answer to a scientific question • An observation is information that is gathered using one of the five senses. • Qualitative • Quantitative • a hypothesis is only useful in science if it can be tested • Decide what result you would expect if your hypothesis is true
Step Three • Setup a controlled experiment. • A controlled experiment only has one manipulated variable and is set-up with a control. • Variables are things in an experiment that can change. • Manipulated or independent variable • Responding or dependent variable • A control is an identical experiment where the manipulated or independent variable is unchanged or removed.
Step Four • Record and analyze the data. • Data • info gathered during observations and experiments
Step Five • Draw a conclusion. • Did your data support or refute (disprove) your hypothesis • Note that we do not say that the data proved the hypothesis. • If your hypothesis is supported then you would go on to perform further studies and eventually publish your results. • If your hypothesis is disproved then you would make additional observations and form a new hypothesis.
Theories • A well-tested hypothesis that unifies a broad range of observations. • Not an absolute truth, but generally accepted by scientists as a likely truth. • Examples: Big Bang or Evolution
How many experiments would it take to disprove a theory? How many would it take to prove a theory?
“No number of experiments can prove me right, but a single experiment can prove me wrong” ~Einstein
When Experiments are Not Possible… • Sometimes setting up a controlled experiment is not practical or possible, in that case we must rely on alternate methods such as a field study.
Redi’s Experiment • In the 1600’s, Francesco Redi set out to disprove the theory of Spontaneous Generation. • Spontaneous Generation was the belief that living organisms arose from nonliving matter. Life from nonlife!!
After Redi • Scientists tried to repeat Redi’s experiments and reached the conclusion that life was actually coming from the air. They called it the life force. However, Louis Pasteur went on the disprove spontaneous generation once and for all.