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In this activity, students build a phylogenetic tree of plants. From the dated tree, students infer when elaiosomes (a plant structure) arose and use this information to examine hypotheses about possible reasons for the evolution of elaiosomes.
DNA to Darwin
Be sure to test the free software used in this lab before attempting it with students. Some users have reported trouble, while others have had none.
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Biological evolution accounts for diversity over long periods of time.
- There is a fit between organisms and their environments, though not always a perfect fit.
- An organism's features reflect its evolutionary history.
- There is a fit between the form of a trait and its function, though not always a perfect fit.
- Similarities among existing organisms (including morphological, developmental, and molecular similarities) reflect common ancestry and provide evidence for evolution.
- Not all similar traits are homologous; some are the result of convergent evolution.
- A hallmark of science is exposing ideas to testing.
- Scientists can test ideas about events and processes long past, very distant, and not directly observable.
- Scientists may explore many different hypotheses to explain their observations.
- Scientists use multiple lines of evidence (including morphological, developmental, and molecular evidence) to infer the relatedness of taxa.
- Evolutionary trees (i.e., phylogenies or cladograms) portray hypotheses about evolutionary relationships.