01 March 2013

Teaching phylogenetics part 2: asking questions.

I wrote a few days back about introducing phylogenetics to an intro bio class. I've been thinking a lot about the lab module I wrote. There were two sections to my lab: the first was a paperclip phylogeny exercise I modified from University of Virginia. In my version, students constructed their own data matrices for morphological paperclips. They then manipulated a random tree entered in Mesquite to look for more parsimonious trees. While they were switching branches around, one student asked, "Aren't there computer programs that do this for us?" I replied, "Yes, but you're not here to learn how to punch a button to make a tree. You're learning how changing a tree topology alters trait mapping and overall tree length." He was quiet for a moment and then said, "That's a good answer."

I believe in telling students what they are supposed to accomplish in lab. In this case, they were expected to learn something about 1) phylogenetic reconstruction methods, and 2) inferring patterns of trait evolution based on a phylogeny. This leads to the second part of my lab: I exposed my students to a new lab format that is simultaneously frustrating and rewarding: the minijournal. The basic premise is that the only materials students receive for the lab is a handout modeled after published scientific journal articles. Just like professional scientists, students must read the article, develop questions based on the "future research" section of the discussion, and conduct their own experiments using methods provided in the article. I learned about this format for inquiry-based laboratory exercises from colleagues at University of Missouri while in graduate school, and was happy to have a chance to expose ~450 students (divided into over 20 lab sections) to the exercise.

Overall, the response for the lab has been better than I expected. Students were thinking deeply about issues involved in phylogenetics, while at the same time, getting their feet wet with developing interesting questions about evolution. Hopefully I'll get permission from the department to post my modified lab exercises so other folks can test them out.


Jen said...

Awesome, Kate!

Jen said...
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