What is a Scientific Explanation?. The Sciences. BiologyChemistryPhysicsEarth and Space Science. What is a Scientific Explanation?. In common usage, an explanation is a statement made to clarify something and make it understandable. In science, explanation" means something more concrete. Scienti
1. Charles Darwin & Natural Selection: Scientific Ways of Knowing Dr. Paul Narguizian
Associate Professor of Biological Sciences
California State University, Los Angeles
Email: [email protected]
Web Page: http://www.calstatela.edu/faculty/pnargui/
2. What is a Scientific Explanation?
3. The Sciences Biology
Earth and Space Science
4. What is a Scientific Explanation? In common usage, an explanation is a statement made to clarify something and make it understandable. In science, “explanation” means something more concrete. Scientific explanations consist of three specific parts: claims, evidence, and reasoning.
5. What is a Scientific Explanation? A claim is an assertion or conclusion that answers the original question.
Evidence is scientific data that supports the student’s/scientist’s claim. It must be appropriate and sufficient. It can come from an investigation or other source, such as observations, reading material, or archived data.
6. What is a Scientific Explanation? Reasoning is the justification that links the claim and evidence. It shows why the data counts as evidence to support the claim, using appropriate scientific principles.
7. Scientific Hypothesis, Law, and Theory What is a Hypothesis?
What is a Law?
What is a Theory?
8. Scientific Fact Fact: In science, an observation that has been repeatedly confirmed (NRC, 1998).
9. Scientific Hypothesis Hypothesis: A testable statement about the natural world that can be used to build more complex inferences and explanations (NRC, 1998).
A hypothesis in the classroom setting usually involves a prediction followed by an explanation.
10. Scientific Law vs. Theory In the language of science, laws and theories are related but distinct kinds of scientific knowledge.
11. Scientific Law Law: A descriptive generalization about how some aspect of the natural world behaves under stated circumstances (NRC, 1998). Laws include predictions made about natural phenomena.
12. Scientific Theory Theory: A well-substantiated explanation/mechanism of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses (NRC, 1998). Theories explain how the law works (McComas, 2003). Scientific theories are explanations that are based on lines of evidence, enable valid predictions, and have been scientifically tested in many ways.
13. Scientific Law vs. Theory Sonleitner, (1989) makes the point that theory and law, are qualitatively different in what they are and what they do. He states that laws are generalizations about phenomena while theories are explanations of phenomena.
Theory and law are not distinguished by their degree of verification.
14. Laws and Theories The Law of Biological Evolution
The Theory of Natural Selection
15. Biological Evolution Defined Biological Evolution is defined as the change in allele frequencies (where alleles are versions of the same gene that differ in their base sequence) within populations (Freeman and Herron, 2004).
16. Biological Evolution Defined Biological Evolution the changes in the genetic composition of a population with the passage of each generation (Volpe & Rosenbaum, 2000).
17. Natural Selection Defined Natural Selection is defined as the process in nature that causes evolution through differential reproductive success among members of a population; that success depends on genetically based and heritable variation in characteristics that confer relative advantage or disadvantage to the bearer (Price, 1996).
18. Natural Selection Defined Natural Selection is defined as those individuals in a population that (genetically) are better able to survive and reproduce in a particular environment leave more offspring, which in turn carry a higher frequency of genes promoting adaptation to that environment (Scott, 2005).
19. Laws and Theories The Law of Biological Evolution
The Theory of Natural Selection
20. Evolution vs. Intelligent Design
22. Physics and the Looming Crisis of String Theory…I Mean String Hypothesis???
23. The Origin of Life vs. The Origin of Species and Other Misconceptions
24. Mechanisms of Biological Evolution The main – but certainly not the only – mechanism of biological evolution is natural selection (Scott, 2005).
Mutation and Genetic Variation
Mendelian Population Genetics
Selection and mutation
Mendelian Population Genetics
Migration, Drift, Non-random Mating/Inbreeding
Evolution at Multiple Loci
Linkage, sex, and quantitative genetics
25. Laws and Theories Laws consist primarily as statements or generalizations made about natural phenomena.
Theories, however, consist of the explanation/ mechanism for how the law works (McComas, 2003). Scientific theories are explanations that are based on lines of evidence, enable valid predictions, and have been scientifically tested in many ways.
Examples? Cell Theory?
26. James Watson’s Definition… “Let us not beat around the bush – the common assumption that evolution through natural selection is a ‘theory’ in the same way as string theory is a theory, is wrong. Evolution is a Law … that is well substantiated as any other natural law, whether the Law of Gravity, the Laws of Motion or Avogadro’s Law. Evolution is a fact, disputed only by those who choose to ignore the evidence, put their common sense on hold, and believe instead that unchanging knowledge and wisdom can be reached only by revelation.
James D. Watson (2005). Darwin the Indelible Stamp:
The Evolution Of An Idea.
28. Evolution Websites Evolution and the Nature of Science
The main objective of ENSI is to improve the teaching of evolution in High School Biology courses by encouraging teachers to teach evolutionary thinking in the context of a more complete understanding of modern scientific thinking.
29. Evolution Websites University of California Museum of Paleontology at UC Berkeley and the National Center for Science Education:
This is a good website for topics that explore evolution content and the NOS.
30. Evolution Websites University of California Museum of Paleontology at UC Berkeley and the National Center for Science Education:
This is a good website for topics that explore lassroom activities, teaching tools, a K-16 conceptual framework, tips, and strategies for integrating the process of science into your teaching, and more.
31. A Responsibility These and numerous other questions regarding scientific ways of knowing can serve as an ideal tool for students and teachers of science alike within courses such as biology, chemistry, physics, and the earth sciences to unite the sciences and reveal the fact that all of the aforementioned sciences use a similar methodology.
32. References Allen, G. and J. Baker. 2001. Biology: Scientific Process and Social Issues. Bethesda, Md.: Fitzgerald Science Press, Inc.
Bybee, R. W. (Ed.) 2004. Evolution in Perspective: The Science Teacher’s Compendium. Arlington, VA: NSTA Press.
Campbell, N.A., Reece, J.B., and Mitchell, L.G. 1999. Biology (5th ed.). Menlo Park, CA: Benjamin Cummings.
Darwin, C. 1964. On the Origin of Species (Facsimile 1st ed.). Cambridge, MA: Harvard University Press.
Freeman, S. & Herron, J.C. 2004. Evolutionary analysis (3rd. Ed). Upper Saddle River, NJ: Pearson/Prentice Hall.
Gould, J.A. 1992. Classical Philosophical Questions. 9th ed. Upper Saddle River, N.J.: Prentice Hall.
Miller, K.R. 2006. Presentation. NSTA Conference. Anaheim, CA.
Miller, K. R. 1999. Finding Darwin’s God. New York, NY: Harper Collins.
Narguizian, P. 2004. Understanding the nature of science through evolution. The Science Teacher 71(9): 40-45.
National Academy of Sciences. (2004). Evolution in Hawaii: A Supplement to Teaching About Evolution and the Nature of Science, by Steve Olson. Washington, DC: The National Academies Press.
National Research Council. 1996. National Science Education Standards. Washington, DC: National Academy Press.
Pennock, R.T. (2005). On teaching evolution and the nature of science. In J. Cracraft & R.W. Bybee (Eds.), Evolutionary science and society: Educating a new generation (pp.7-12). Washington, DC: AIBS/BSCS.
Peterson, G. R. 2002. The intelligent design movement: Science or ideology? Zygon 37(1): 7-23.
Price, P.W. (1996). Biological evolution. New York: Saunders College Publishing.
Scott, E.C. (2005). Evolution vs. creationism. Berkeley, CA: University of California Press.
University of California Museum of Paleontology at UC Berkeley and the National Center for Science Education: evolution.berkeley.edu/evosite/evohome.html
Volpe, E.P. & Rosenbaum, P.A. (2000). Understanding evolution. New York: McGraw Hill.