Last night I had my first Biology 102 class meeting, kicked off with the usual speech about academic integrity, lab issues, etc. I swear, I could probably give the instructions myself at this point. After all the bureaucratic demands were met, however, the professor began a discussion of classification, reciting the famous “King Philip’s Chef Orders Fresh Green Spinach” for Kingdom-Phylum-Class-Order-Family-Genus-Species (with the alternative “Kinky People Come Over For Great Sex”) and mentioning Linnaeus as the “father” of our binomial nomenclature systems. This was all well and good, but then she attempted to make the differentiation between “classification” and “systematics.” She said that classification does not necessarily reflect evolution while systematics has evolution primarily in mind, but this struck me as rather odd. In classifying organisms, isn’t the evolutionary history at least somewhat inherent in the placement of a living thing at the various levels of classification? This isn’t to say that evolution is necessarily always assumed, but it seems to me that in figuring out how closely related one organism is to another (and lots more of varying degrees of similarity as we move up the “ladder” of classification) evolutionary relationships should become self-evident. Obviously Linnaeus didn’t have evolution in mind when he came up with his system, but that doesn’t change the fact that the way in which he organized life reflected its evolutionary history to greater or lesser extent.
After this the professor moved on to the concept of species, quoting Ernst Mayr for the definition. She did mention that for paleontologists, a definition based upon who breeds with whom does not work and makes it necessary to have “morphospecies”, but I think she really shortchanged the rest of the audience as to the controversy surrounding something as seemingly “obvious” as species. Sometimes species don’t “stay where they’re put” as far as reproduction goes, creating hybrids or variations not otherwise seen such as when a wolf and dog interbreed. This is the most widely cited example, but if we think beyond animals for a moment, plants can more readily hybridize and defining species by reproductive habit doesn’t suit botanists well at all. We can’t even say “Well, if there are less than 5 derived characters that are different, then it’s a different species” because such is an arbitrary judgment and what differentiates a species might be something as subtle as behavior, especially if a speciation event has occurred recently. What if two animals look almost exactly alike and can interbreed but do not because of geographic or behavioral reasons? Are they two different species? I’m sure a whole lecture series could be done on the topic, but that would take far too much time in a fast-paced biology course. Even so, sometimes “keeping-it-simple” can do a disservice to students, I think, and I would have taught the lecture differently.
Another thing that irks me is the nearly ubiquitous (at least during my own education) need to put ecology and evolution at the end of the course. These are two important concepts that could be better understood by keeping track of relationships throughout the course, but instead they are relegated to about 3 weeks worth of lectures at the end as their own separate topics. I think they really should be bookends, the basics introduced at the beginning and then used at the end to tie everything together, as how can you hope to understand biology if you can’t understand the ecology and evolution? I’m sure many in the class are going to move on to be doctors and aren’t as concerned with more “abstract” principles or relationships, but this is partially why there is such controversy involving evolution today; it is not taught correctly, even at the college level.