The discovery of the platypus had the scientific world in an uproar with its mammal-like and bird-like features. How was one to classify the platypus? This case study uses this issue to model the scientific process, with scientists arguing, debating, collecting more evidence, and revising their opinions as new data become available.
Herreid, Clyde Freeman
1 to 2 hours, ideally split over multiple class periods
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Present-day species evolved from earlier species; the relatedness of organisms is the result of common ancestry. (LS4.A)
- An organism’s features reflect its evolutionary history.
- Similarities among existing organisms provide evidence for evolution. (LS4.A)
- Anatomical similarities of living things reflect common ancestry. (LS4.A)
- Evolution does not consist of progress in any particular direction.
- A hallmark of science is exposing ideas to testing. (P3, P4, P6, P7)
- Scientific knowledge is open to question and revision as we come up with new ideas and discover new evidence. (P4, P6, NOS3)
- Our knowledge of the evolution of living things is always being refined as we gather more evidence.
- Our understanding of life through time is based upon multiple lines of evidence.
- Classification is based on evolutionary relationships.
- Scientists may explore many different hypotheses to explain their observations. (P7)