What is Science?

1. What is Science? • The Nature of Science and Scientific Inquiry

2. The Nature of Science • Science is based on observations and inferences about the natural world (empirical evidence). • Science is a creative human endeavor that is socially embedded. • Scientific knowledge is always tentative (subject to change with new knowledge. • Laws and theories are the products of science.

3. Hypotheses • An hypothesis is a statement that predicts the outcome of an experiment. • An hypothesis may be stated as a null hypothesis; that is, the hypothesis may predict no change. • Hypotheses are tested by scientific inquiry. • Tested hypotheses help build scientific knowledge.

4. Scientific Laws • A scientific law is a description of a natural phenomenon. • Laws are based on empirical evidence. • Examples: • Mendel’s laws of inheritance. • The Hardy-Weinberg Law of population genetics. • Laws may change with new knowledge.

5. Scientific Theories • A scientific theory is an explanation of a natural phenomenon. • Theories are based on empirical evidence. • Examples: • The theory of natural selection. • Cell theory. • Theories may change with new knowledge

6. Scientific Inquiry • Scientific inquiry is the process that results in building scientific knowledge. • There are three main types of inquiry (scientific studies): • Descriptive • Correlational • Experimental

7. Descriptive Studies • Descriptive studies describe the object of study in detail. • Characteristic of young sciences. • Some sciences, such as Astronomy and Taxonomy, rely almost entirely on descriptive studies.

8. Correlational Studies • Correlational studies describe two events that occur at the same time, and look for a relationship between the two. • Many health studies are correlational: they use large databases of health information, and try to answer questions when an experiment would be unethical. • However, a correlation does not prove a cause.

9. Experimental Studies • Experimental studies involve setting up control and experimental groups in order to the effects of one variable on another. • Experiments can be used to determine cause. • Experiments are used to test hypotheses (not to “prove” them).

10. Who is a scientist?

11. Who is a scientist? Ecologists

12. Who is a scientist? Microbiologists

13. Who is a scientist? Taxonomists

14. Who is a scientist? Geneticists

15. Who is a scientist? Botanists

16. Who is a scientist? Molecular Biologists

17. Who is a scientist? Zoologists

18. Science: A Human Endeavor