2. Chapter 1 What is Biology? 1.1 Science and the Natural World

3.  Objectives  Identify the goal of science.  Describe how scientists study the natural world.  Explain how and why scientists do experiments.  Describe types of scientific investigations.  Explain what a scientific theory is.

4. Vocabulary  Dependent variable  Evidence  Experiment  Hypothesis  Independent variable  Model  Observation  Prediction  Science  Scientific investigation  Scientific law  Scientific method  Scientific theory

5. Graduation Standards 9.1.1.1.2 Understand that scientists conduct investigations for a variety of reasons. 9.1.1.1.4 Explain how societal and scientific ethics impact research practices. 9.1.1.1.6 Understand how changes in scientific knowledge generally occur in incremental steps that include and build on earlier knowledge.

6. What is science?  Science can be defined as a systematic approach to studying the physical and natural world.  Science is always changing.  Anyone can “do” science. All you need are the basic understanding and skill set, and a curious mind. Click here for audio

7. Goal of Science  We study things in a scientific way so that we can better understand them.  We need to keep in mind:  Scientific studies of nature are systematic  Scientific conclusions are able to be revised  “Good” science can stand the test of time  Science cannot answer all questions Click here for audio

8. Understanding Nature  Natural Laws are based on repeating events that occur in the world around us.  A natural law could be stated “What goes up must come down”.  Natural Laws can be explained as Scientific Laws: descriptions of natural occurring events and the conditions that they happen under.  The scientific law of gravity describes why that natural law is mostly true. Click here for audio

9. The Changing Nature of Science  Don’t think of science like an encyclopedia full of information.  Think of it as a process, or a way of thinking and acting in order to gain new knowledge.  When we gain new information it often builds on previous information.  Separate explanations can actually be intertwined with one another.

10.  Like genetics and evolution.  We often use principles of genetic and inheritance to understand how evolution occurs. Click here for audio

11.  Sometimes scientific theories are changed, as new tools are developed, new information is found and new discoveries are made.  Even though some scientific ideas might not be 100% correct doesn’t mean that they don’t have value.  That’s the best thing about science. It’s always changing, and improving.

12. Staying Power  Many scientific ideas have been around for decades or centuries.  As long as a valid scientific idea can withstand repeated testing it will remain unchanged. Only when it can be proven with evidence will it be changed.

13. Unanswered Questions  The nature of science is that questions are answered when data or evidence can support it and a logical solution can be presented.  Evidence and logic are based on observations.  Questions that can be answered with evidence, logic, and experimentation can be answered scientifically.

14.  Questions that can only be answered by opinions, belief, or cannot be supported with facts or evidence are not able to be answered scientifically. Click here for audio

15. Scientific Method  Remember that the definition of Science is that it is a systematic approach to studying the physical and natural world.  A scientific method is any method that is repeatedly used to come up with an answer to a scientific question.  There is no ONE SINGLE scientific method. Click here for audio

17. General steps of a scientific method  Often the first step in a scientific method is observing some sort of an event.  And having some sort of question about the physical or natural event that you would like answered.  The next step is what differentiates a scientist from a casual observer.  The scientist wants to investigate the question and begins that investigative process by forming a hypothesis. Click here for audio

18. What makes a hypothesis?  A hypothesis is a plausible answer to the question asked that is based on some sort of logic or pre-existing knowledge.  It is basically a prediction of what will happen in a controlled set of conditions.  It’s really not correct to call a hypothesis an “educated guess”, because it’s not a guess…it’s an answer that has a high likelihood of being true. Click here for audio

19. The next big step  After a hypothesis is proposed then a true scientist must design an investigation that will provide evidence of to supported or refute the hypothesis.  Investigations involve the collection and analysis of data.  Based on the data collected a conclusion is made. Click here for audio

20.  Many conclusions do not completely answer the question or do not answer the question at all.  That does not mean that the process was a failure! It simply means that one possibility has been ruled out. Click here for audio

21. Experiments  An experiment is a special kind of scientific investigation that involves careful planning and is performed under controlled conditions.  Scientific experiments must meet certain criteria in order to be considered valid.  We call these “Controlled Experiments” Click here for audio

22. A Controlled Experiment  Experimenting tests how one variable is affected by another.  The affected variable is called the dependent variable, because what happens to it depends on something else.  The variable that affects the dependent variable is called the independent variable because it does not depend on any other factor. Click here for audio

23.  In a controlled experiment it is typical to only test one dependent variable at a time.  Testing more than one variable can produce uncertain results and can decrease the reliability of the experiment.  Another factor that exists in the experiment is the control setup.

24. Control Setup  When performing a controlled experiment the scientist may choose to leave one part of the experiment alone and not make any changes to the dependent variable.  This is done as a standard for comparison. Click here for audio

25. Other Types of Investigations  Natural Studies: experiments performed in a natural setting vs. a laboratory setting.  Modeling: Making and manipulating a model of a part of the real world.  Other Types of Investigations defined Other Types of Investigations defined Click here for audio

26. Scientific Theories  Theory in the scientific sense is a broad explanation for a natural event that has been widely accepted as true because it has be repeatedly tested and is supported by a great deal of evidence.  A scientific theory is more like a fact than it is like a guess because of the evidence that supports it. Click here for audio