Lesson 8

What Gives Us Evidence that Different Types of Organisms are Related?

Big Idea: A natural selection story about a trait change in a population of one species (adaptation) is essentially the same as a story about changes that result in a new species (speciation). Fossils formed thousands of years ago offer evidence of species that lived a long, long time ago.

Activity: Students discuss the similarities and differences between a story about adaptation – the evolution of a specialized trait (piloses) versus a story about speciation – the evolution of a new species (miroungas). Then they turn their attention to scientific evidence for changes that happened many hundreds of years ago. In this context they are introduced to fossils. After a short video on the process of fossilization, they use a set of picture cards of everyday plants and animals to speculate what fossils of those organisms might look like.

Materials to Have Ready

• Pictures of present day animals and plants- what parts might become fossils?

Video Overview (1:59)