This high school unit on natural selection and evolution starts out with students exploring the case of a young girl with a life-threatening infection of pan-resistant bacteria. This case sparks questions that lead them to investigate the growing prevalence of such cases and the discrepancies between antibiotic use in their communities and CDC recommendations. As they develop a model to explain how bacteria populations change over time, they expand their investigations to look at whether similar population changes are occurring in a population of birds (Juncos).
What students figure out
By the end of the unit, students develop ideas on natural selection & evolution including:
- Natural selection occurs only if there is both (1) variation in the genetic information between organisms in a population and (2) variation in the expression of that genetic information—that is, trait variation—that leads to differences in performance among individuals. The traits that positively affect survival are more likely to be reproduced, and thus are more common in the population. Natural selection leads to adaptation.
- Evolution is a consequence of the interaction of four factors: (1) the potential for a species to increase in number, (2) the genetic variation of individuals in a species due to mutation and sexual reproduction, (3) competition for an environment’s limited supply of the resources that individuals need in order to survive and reproduce, and (4) the ensuing proliferation of those organisms that are better able to survive and reproduce in that environment.
- Changes in the physical environment, whether naturally occurring or human induced, have contributed to the expansion of some species, the emergence of new distinct species, and the decline–and sometimes the extinction–of some species.
- Genetic information provides evidence of evolution; multiple lines of descent can be inferred by comparing the DNA sequences of different organisms.
- Vicki Brown, High School Biology Teacher, Denver Public Schools, Denver, CO.
- Jill F. Carter, Science and Environmental Education Consultant, Pekin, IL
- Jennifer Jacobs, Research Associate, University of Colorado Boulder, Boulder, CO
- Mike Kraft, High School Biology Teacher, Denver Public Schools, Denver, CO.
- Katy Fattaleh, K-8 Instructional Coach, South Park School, Deerfield, IL
- Mike Fumagalli, Assistant Dean of Students, Glenbard East High School, Glenbard, IL
- Kent Hups, High School Biology Teacher, Adams 12 Five Star School, Thornton, CO
- Kevin Lindauer, High School Biology Teacher, Denver Public Schools, Denver, CO.
- TJ McKenna, Science Specialist, Connecticut Science Center, Hartford, CT and University of Connecticut, Storrs, CT
- Tara McGill , Curriculum Development Specialist, Northwestern University School of Education and Social Policy, Evanston, IL
- Michael Novak, Senior Curriculum Developer, Northwestern University School of Education and Social Policy, Evanston, IL
- William Penuel, Professor of Learning Sciences, University of Colorado Boulder, Boulder, CO
- Brian Reiser, Professor of Learning Sciences, Northwestern University School of Education and Social Policy, Evanston, IL
- Kristin Rademaker, Life Science & Special Education Teacher, Harlem High School, Machesney Park, IL
- Tricia Shelton, High School Biology Teacher, Randall Cooper High School, Union, KY
- Stephanie Spiris, High School Biology Teacher, Denver Public Schools, Denver, CO.
- Katie Van Horne, Postdoctoral Researcher, University of Colorado Boulder, Boulder, CO
- Dan Voss, High School Chemistry Physics Teacher, Boone High School, Boone, IA
- Douglas Watkins, High School Science Curriculum Specialist, Denver Public Schools, Denver, CO.
- David Quigley, Graduate Researcher, University of Colorado Boulder, Boulder, CO
- Holly Devaul, Mgr. of Educational Programs at University Corporation for Atmospheric Research, Boulder, CO
- Tammy R Sumner, Professor of Cognitive and Computer Science, University of Colorado Boulder, Boulder, CO