I'm almost halfway through teaching "molecular ecology" to 10 PhD and MS students and a handful of postdocs. Today we are grappling with the history, and more importantly the contemporary view, of phylogeography - a method to understand how time and space and the earth sciences interact with time and demography and evolution.

I feel almost guilty that, with high hopes as the course began, I have settled into a weekly pattern: Tuesdays we tend to open class with a little "molecular ecology moment of zen" to re-wrap everybody's minds around the topic at hand, usually a short exposition of a paper that has just been published (today it was this cool one on spider phylogeny), and then I lecture.

(Thursdays are for practical exercises and discussion of a paper or concept, led by a student and often heavily facilitated by me)

The lecture part though - I'm supposed to be embarrassed by this these days. We are told from all directions that our students need to be engaged frequently, that blocks of talking longer than 10 minutes are hard for them to stay focused on, that practical experience trumps even the best presentation of a topic. And I'm not skeptical of these claims. It makes sense, practice and the experience of turning data over with mind and hands is hard to replace. In my class, the students are required to do most of this outside of the classroom - analysis of data and computational work. This is in part because we don't have much time, and my experience (teaching for 2 weeks with Jim Hamrick in Costa Rica, as well as leading an evolution lab course for 5-6 years) is that when computational work is involved, a good 25% of the time an instructor spends teaching the method in the classroom is acting as IT, fixing permissions and login issues, reminding the students which button to push, and when.

That … is not my job. Part of the learning of analysis is figuring out how to make it happen on your own computer, with the quirks of your own data, with the ability to absorb the output of each step. So I avoid bringing this into the classroom, when I only have 75 minutes twice a week to work with the students. That I feel can be safely left to them to explore. So I also engage, I ask questions, we work through things on the board (my style with a wipe-erase board could be improved I"m sure).

But mostly, on Tuesdays, I lecture.

And I feel guilty about this, but maybe I shouldn't. A contributed op-ed to the New York Times last year valiantly defended the lecture, and claimed it as still relevant to the humanities. One of several points made that resonate with me is that I, having 20 years experience working in this facet of the sciences, have experience that not only can be shared but can be harnessed to distill what is most important for students to consider. Our class has a textbook (maybe that was a bad idea), and reading the relevant chapter yesterday made me frustrated for all that it didn't convey. Each week, my 75 minutes at the pulpit is my opportunity to shine a light on what I think is most important about our topic (remember, it is "molecular ecology" - the use of genetic or other biochemical markers to help illuminate ecological processes like demography, dispersal, isolation and interaction).

It's my chance to shape how these students will think about the field in the future. There isn't a set encyclopedic entry for the field that will guide them in that way (wow, does that entry merit some update/addition…). Perhaps that makes a course like this very different from introductory biology, where active learning is perhaps far more appropriate. When we go to graduate school, whether we realize it or not you are being inculcated in particular philosophies and approaches to science, with a goal of exploring what we don't yet know. When I chose between University of Connecticut, Duke, and George Washington University (probably my top 3 choices at the time, though really it was UConn and Duke far at the top), I didn't realize that one of those choices would have dramatically changed me as a scientist. One of those schools had a fundamental, philosophically different approach to molecular systematics than the other two (those I was going to work with at GWU were cladists who didn't like modern statistical/likelihood approaches to phylogeny; I learned from some of the greatest minds in the advancing field at Duke).

So, today I had a chance to dismiss the treatment their textbook gave to nested clade analysis (as an example). To push them to understand the contributions of coalescent theory, for all the complexity it appears to add it is truly an elegant mathematical approach to exploring the history of population genetic diversity. And I took that opportunity, and take it each week. I talk to them. I tell them what I think. I help them see my reasons.

I don't know if I'm a good lecturer. But I lecture. I'll admit it.