When I give seminars about my work and when I write grant proposals, I often talk about how tractable it is – the hosts are see-through, allowing you to see internal parasites! You can maintain individual genotypes in the lab for years! Population dynamics are fast, so you can watch evolution in a natural population over the course of a single season!
That’s all true, but it ignores something else: even tractable systems are hard. I think of this especially at this time of year because we’re in the midst of field season (our field season runs from July through November) and because there are new folks in the lab who need to be trained. I feel like I talk a lot about the cool things we can do with our system when I’m recruiting folks to the lab, so then I feel a little bad when they arrive, eager to get involved in our field survey, only to find out that they can’t help with counting samples.* In order to be able to count field samples, the person needs to be able to identify seven different species of host (and Daphnia are literally a textbook example of phenotypic plasticity), plus a whole suite of parasites (there are ~8-10 that we see routinely, plus various other ones that we see less commonly). That’s a lot to learn how to identify all at once. Actually, it’s too much to learn how to identify all at once, and, as a result, grad students (and technicians) usually spend a full year in the lab before they can count any of the field samples. And, as I’ve written about before, lab experiments often have lots of failures, sometimes for inexplicable reasons. And, when piloting new experiments, sometimes things that should be really straightforward don’t work, and it can take years to figure out why. (As one example, we’ve spent the past two years troubleshooting something that seemed like a slam-dunk experiment and still haven’t figured out the problem.**)
I am not claiming that my study system is especially hard. I think everyone’s systems have advantages and disadvantages, even if it’s easy to focus more on the advantages and disadvantages and end up with system envy when you see someone’s polished talk or publication. But I sometimes wonder if I’ve oversold the tractability of my system. In the end, I have to remind myself that, unfortunately, tractable is different than easy.
*I do say this during the recruitment process, too.
** But I have a new hypothesis for something that might be causing the problem! Hope springs eternal.