First class, last class

First Class/Last Class

I typically have a rough time with last lectures. First lectures are easy—your head is clear, there is no personal history between you and the students to complicate communication, and you haven’t made any mistakes yet. Last lectures are tough. The stress of the end of the quarter fills your mind, and standing at the front of the chalkboard is like standing at the focus of a parabolic reflector of undergraduate anxiety. A class of undifferentiated freshmen has become a class of individuals: the ones that are smarter than you, the ones who planktonically drift towards failure, the angry whiners and grade-grubbers, the earnest strugglers who through might and main are dragging themselves from a C to an A-. Addressing a class is just public speaking; addressing these individuals who you know personally demands personal communication.

The hardest thing on the last lecture is the mistakes. I should say "mistake," because it's always the same one: I’ve somehow forgotten to tell them just how much they should love the subject for its poetry and emotion. So, I read Darwin’s tangled bank, or emphasize how a single mutation can change the history of life on earth, or how every atom in their bodies was formed in a star and recycled through thousands of lives…and I get choked up. Usually, I make it through, but it’s rough.

I was really worried that this time would worse—after all, not only the last lecture for this class, but my last lecture at Davis. I decided to try a slightly different tack. This was the first biology class for most of my students, and rather than make the envoi about me and my love, I made it a challenge for them: ten big problems that I thought could be solved during their science careers. This list is by no means comprehensive—in fact, it was designed as much to prompt review as anything else. I could add lots of other things, but it was fun to think about:

1. In the laboratory, make a self-replicating molecule or assemblage of molecules.

2. Make a simple cell from scratch (not Ventner’s reboot), or completely model one on a computer.

3. Effectively use biological systems to clean up the messes of the 20th century—from superfund sites to Hanford nuclear reservation. This will require an understanding of metabolism and genetics

4. Make a solar cell that simply comes close to the efficiency of rhodopsin or a chlorophyll-based photosystem.

5. Understand photosynthesis—from the initial excitement of an electron by light, to how to split water at room temperature, to consuming CO2 to make fuel.

6. Fix nitrogen efficiently. The Haber process, which produces ammonia from atmospheric nitrogen, and which modern agriculture depends upon, consumes somewhere between 2 and 5 percent of all natural gas production worldwide.

7. Understand the central dogma in Archaea. We just don’t understand how these cells work.

8. Understand how proteins fold, so that we can not only predict the structure that comes from a given sequence of amino acids, but design a sequence of amino acids that will give a specific structure.

9. Use viruses for therapy. This includes “gene therapy,” which has been the medicine of tomorrow for about three decades, as well as phage-based antibiotics.

10. Understand the role of Viruses, Archaea and microbial Eukaryotes in the environment. These have been called the “Dark Matter” of the biosphere, and we just don’t know what they do. It’s as if 70% of the economy was the black market.

(Bonus number 11—understand development. This is another thing we just don’t fully understand in biology, and it’s a neat problem.)

Well, I managed to get through it without choking, and to my surprise, I got a round of applause at the end. Kind of gratifying, but I’ll be happier, more like ecstatic, if one of my students goes on to actually solve one of those problems. I think they can.

Feel free to suggest further problems to be solved in the next 20 years.