Using Claim-Evidence-Reasoning with a computer-based natural selection simulation

I had a great success last Friday using Claim-Evidence-Reasoning to get my students to think about an on-line natural selection simulation (I use this one because it runs on the Chromebooks that I have easy access to at my school).

Here’s what I did (click here for a worksheet that will guide your students through the whole thing. It includes a list of the relevant AP Bio learning objectives).

  1. I started by having my students learn about the peppered moth by going through the excellent web-based tutorial about natural selection at This leads up to a simple simulation game. Two notes about this. 1) There’s an error in the text that describes Kettlewell’s experiments (I contacted the administrators of the website: they can’t fix it). 2) This runs in adobe flash: it will work fine on almost any computer, but not on an iPAD.
  2. That experience took about 45 minutes, and leads up to the main activity: the NetLogo simulation. Before that activity,
    1. I reviewed the difference between independent and dependent variables (most of my students had been taught this in previous courses at BHS)
    2. I modeled how to do CER. I’d been exposed to this several times, but this is the first time I’ve explicitly used it in my class. I used the following websites for reference:, and–HelpingStudentsWriteAboutClaimsandEvidence_12-12-2012.pdf
  3. I gave my students the rest of the period (about 45 minutes) to play with the simulation. Their predictions were their claims. The data that came out of the simulation became their evidence. Their explanation for why the simulation gave the results it did was their reasoning.
  4. I spent about another 20 minutes having students give mini-presentations of their C-E-R models to the class. I have a document camera, and one representative from each group of four came up to explain their results to the class.

It’s a pretty big commitment of time (about 2 and 1/2 class period). But evolutionary thinking seems to be one of the core skills that students should gain in an AP Biology class (it’s one of the 4 Big Ideas, right?), so I’m hoping that it’ll pay off throughout the year. Let me know what you think!