Students compare different subspecies of a California salamander on a grid map of California to focus on patterns of their distribution, their likely evolutionary relationships, and probable sequence of formation from the ancestral salamander.
Two 50-minute periods
Correspondence to the Next Generation Science Standards is indicated in parentheses after each relevant concept. See our conceptual framework for details.
- Speciation is the splitting of one ancestral lineage into two or more descendent lineages.
- Speciation requires reproductive isolation.
- Occupying new environments can provide new selection pressures and new opportunities, leading to speciation. (LS4.C)
- A hallmark of science is exposing ideas to testing. (P3, P4, P6, P7)
- Scientists can test ideas about events and processes long past, very distant, and not directly observable.