Students focus on the evolution of three species of lizards using real data sets – geographical and geological data, then morphology, and finally molecular data – to determine possible phylogenetic explanations.
Two full class periods
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. (LS4.A, LS4.D)
- Traits that confer an advantage may persist in the population and are called adaptations. (LS4.B, LS4.C)
- Speciation is the splitting of one ancestral lineage into two or more descendent lineages.
- Occupying new environments can provide new selection pressures and new opportunities, leading to speciation. (LS4.C)
- Scientists test their ideas using multiple lines of evidence. (P6, NOS2)
- 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.
- Scientists use the similarity of DNA nucleotide sequences to infer the relatedness of taxa. (LS4.A)
- Scientists use anatomical evidence to infer the relatedness of taxa. (LS4.A)
- Scientists use the geographic distribution of fossils and living things to learn about the history of life.
- Classification is based on evolutionary relationships.
- Evolutionary trees (i.e., phylogenies or cladograms) are built from multiple lines of evidence.
- Speciation is often the result of geographic isolation.
- Evolutionary trees (i.e., phylogenies or cladograms) portray hypotheses about evolutionary relationships.
- Scientists may explore many different hypotheses to explain their observations. (P7)