In this lab activity, students examine authentic morphological and phylogenetic data of three fish families and then pose and test alternative hypotheses about the fishes' classification.
Life Science, Nature and Process of Science
4 - 5 class periods
Though this is a multi-day lab, it is worth the investment in time as it engages students in the process of science while also reinforcing multiple evolutionary concepts.
Students should have a basic understanding of how to read and interpret phylogenetic trees.
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Science is both a body of knowledge and the process for building that knowledge. (NOS5)
- Science works only with testable ideas. (P2, P3, NOS2)
- Scientists strive to test their ideas with evidence from the natural world; a hallmark of science is exposing ideas to testing. (P3, P4, P6, P7, NOS2)
- Scientific knowledge is open to question and revision as new ideas surface and new evidence is discovered. (P4, P6, NOS3)
- Science is ongoing; answering one scientific question frequently leads to additional questions to be investigated. (P1)
- The process of science involves observation, exploration, testing, communication, and application.
- Scientists test their ideas (hypotheses and theories) by figuring out what expectations are generated by an idea and making observations to find out whether those expectations are borne out. (P4, P6)
- Scientists test their ideas using multiple lines of evidence. (P6, NOS2)
- Scientists often try to generate multiple explanations for what they observe. (P7)
- Scientists use multiple research methods (experiments, observational research, comparative research, and modeling) to collect data. (P2, P3, P4, NOS1)
- Scientists look for patterns in their observations and data. (P4, P5, NOS2)
- Different scientists may interpret the same data in different ways. (P7)
- Researchers share their findings with the scientific community through scientific publications. (P8)
- Hypotheses are proposed explanations for a narrow set of phenomena. (P6)
- Hypotheses are usually inspired and informed by previous research and/or observations. They are not guesses. (P6)
- Science depends on communication within the scientific community. (P7, P8)
- Scientists scrutinize each other's work through peer review and other processes. (P7, NOS5)
- Science relies on the accumulated knowledge of the scientific community to move forward. (NOS5)