Evolution can be a subject that causes stress for some teachers because they worry about how students (or their parents) may feel about the subject. I’ve even heard from some teachers that choose to skip the chapter rather than cause controversy, and sadly, some administrators of schools are not supportive. Many years ago, an administrator came to me asking about putting “disclaimers” in the biology textbooks that said something like “evolution is just a theory…blah blah blah.” I said I’d be willing to consider it if they were going to treat other theories the same way, that means disclaimers would need to go into chemistry books, physics books and earth science books. I also asked for him to write a disclaimer about the germ theory – because really we can’t know ~for sure~ how pathogens cause illness in the body. He didn’t bring it up again, and has long since retired, but I do know that teachers are currently working in environments that do not support the teaching of evolution. The National Center for Science Education has a stockpile of resources to help teachers who may be feel pressured about the topic.
How I cover the topic depends on the class and the age group. I tend to be more open to discussion and exploration of the topic with older students, whereas 9th graders usually stick to the chapter and the facts.
All of the resources I have used, both past and present can be found at the Evolution and Taxonomy page.
This is the basic timeline I use for the unit on Evolution.
1. Discuss the history of evolutionary thought, including Darwin’s voyage of the Beagle and the observations he made at the Galapagos Islands. With older students, I include a more in depth look at other scientists, like Alfred Wallace and Lamark.
Video: Darwin’s Dangerous Idea – pbs theatrical program about Darwin’s life and research
Examining the Fossil Record – students cut out paper fossils and arrange them on a geologic timeline
2. Examine the processes of evolution – students get a detailed look at how natural selection works and perform simulations to gain a better understanding of the process. I have several activities that I use for different classes and ability levels.
Video: Your Inner Fish – this program explores the relationship between fish and land vertebrates, focusing on homologous structures of the forelimbs and how fossils are studied
Virtual Lab – Bunnies and Selection – phet simulation uses wolf and bunny populations to demonstrate how coloration can provide an advantage. (9th)
3. Compare Specific Types of Evolution – not all changes in species are a result of natural selection. Here students learn about other mechanisms, such as sexual selection, gene flow, genetic drift. Students also learn specific ways in which new species arise.
Sex and the Single Guppy – guppy numbers are examined in ponds with varying numbers of predators, illustrates sexual selection (9th)
HHMI Stickleback Evolution Virtual Lab – this lab has printable worksheets and takes a in depth look at different morphologies in stickleback populations. I love this lab for AP biology because it utilizes real-world observations and data collecting to show how one species could diverge into two species. (AP Bio)
Case Study – A Tale of Three Lice – this case study explores the evolutionary history of lice, focusing on the difference and similarities of head lice, body lice, and pubic lice. The case asks students to map the evolutionary history of these organisms. (AP Bio)
I have accumulated so many different activities that relate to evolution, there is no way that I could do them all in a biology class. I often mix them up from year to year, just to keep things interesting and I am always on the lookout for new resources. Students sometimes have the mistaken idea that evolution is something that occurred in the past, so including modern research shows them that we are still studying it, and still learning things about relationships between organisms and how new species arise.