Why do we dissect?
Half way between where I sit and the advance guard of Winter Storm Nemo, sits a bucket that contains a lot of formalin and two large freshwater mussels. Also on that table is two bivalve pairs, cleaned out yesterday after we hacked up the mussels inside them.
It was a messy, disorganized process that hit a snag very early on when I handed the kids (aged on a continuous spectrum between 5 and 10) their mussels and told them to prise them open. In the 10 years since I last carried out a mussel vivisection during my undergraduate degree, muggins here forgot about the ridiculously strong adductor muscles that keep the shell firmly closed even in death. What resulted was five straight minutes of me hacking between the shells with a scalpel while fending off such “helpful” instructions as “SMASH IT WITH A HAMMER!”
(Meanwhile, one of our high school interns sliced the second open with no problems.)
At no point did it look like this. Image Credit: University of Wisconsin
Teaching with an age group as diverse as this one isn’t easy. Especially when there are scalpels involved: when the enthusiastic explorers are hacking flesh apart, I find my attention ripped away by younger children who, at the end of a long school day and nearing the end of an even longer school week, are losing their grip on their ‘indoor voice’ button. At the end of the class, one mussel was ripped asunder, and the other neglected and under appreciated.
It certainly wasn’t a textbook example of how a dissection class should go. And even though I’m still improving as a teacher, there are ways in which this class if never going to look like the focused, guided classes I remember from high school and college. And if it ever does, I’ll be doing my kids a disservice.
So why am I ripping animals apart with the help of children as young as five? What could they be getting out of it?
Well, I don’t expect the elementary schoolers to be able to label a detailed diagram of muscle internal anatomy. I don’t really expect them to be able to explain what we found (and didn’t find) when we pulled apart a Grantia specimen a few weeks ago, either. As much as I’m a - excuse me - sponge for facts sometimes, facts are not the point here. There are other things I’m hoping to impart to my students as we pick apart everything from a porifera to a frog.
- Getting your ‘ews’ out
Dissection is on the face of it, a pretty gross act. Formalin smells. Gut contents can feature heavily when, for example, you’re cutting up an earthworm. We have, learned from the people around us, picked up this idea that anatomy is icky and that animal bodies - and by extension our own - are therefore taboo, disgusting things. We moved past the ‘ew’ phase pretty quickly in our worm lessons, and there’s a culture of respect coming out. - Activation of Interest
“Ugh, we going to cut something up?” in the first week from one of the boys, became “please can we dissect next week too?” within the course of an hour. Because, honestly? Getting your hands on a real, once living animal and being able to see a part of it you never have (and, let’s be honest, the ‘ew’ factor) is fun. It’s not something you do often (at least, not until you realize that every meal time is actually a dissection class, and your friends vow never to eat chicken in front of you again) and it’s exciting. Igniting a kid’s interest in science is rarely more complicated than showing them a new way to explore.
- Experience gives Meaning
It’s nice to know things. But knowledge means absolutely nothing until you’ve seen, heard, felt, experienced something. I’m looking out of the storefront right now at a New York street being covered in snow. I know that snow is cold, but I understand how cold it is and even what cold means because I have stood outside in snow and been cold and wet and felt the bite. It’s all very well telling kids that bivalves have gills that serve the same function as a fish’s gills until they’ve seen, touched felt, accessed those gills themselves. No one wants to hear me lecture. Not when the alternative is experience. - Repetition and Familiarity
There’s a reason we started with sponges: they are relatively simple, there’s not too much to see (although, as with everything, what there is depends on the experience of your eye and the knowledge of what to look for.) While I tend to avoid discussion of ‘primitive’ and ‘advanced’ in zoology, getting used to guts and hearts and muscles will come in handy when faced with the detailed interior of a frog. - Conceptual Framework
One word I have no intention of bringing up in class is “homology” - although I expect that one or two of the 9/10 year olds will eventually ask a question that will force it out of me. We’re creating a biodiversity catalog, we’re not discussing evolutionary relationships. (We only have an hour a week. We only have time for taxonomy and anatomy.) I’m not going to discuss how bilateral and radial symmetry may have evolved. But we have seen some animals that are symmetrical in a mirror and some that are rotational. We’ve seen that the digestive system has some important similarities among phyla. When it comes to vertebrates, the heart, lungs, skeleton, stomach will be right there. I don’t care whether or not someone will be able to say exactly what a mollusc has in common with a frog, but once you look inside, the similarities are there. And when they are ready to start thinking about the interrelationships between animals, ourselves included, they will always have the memory of exactly how alike we all are underneath.
This post can also be found at Thagomizer.net. Feel free to join in the conversation wherever you feel most comfortable.