Wednesday, August 17, 2011

Taxonomy: Art or Science?

When Googling "science definition," the first thing that came up was "The intellectual and practical activity encompassing the systematic study of the structure and behavior of the physical and natural world through observation and experiment." After a little more research, I was surprised to see that this seems to be one of the stricter definitions of science (others may be as broad as "the state of knowing" or some such...), but it is one with which I can get on board. I tend to think of science itself in a very strict sense, as the process of developing and testing hypotheses. However, my big caveat is that there are many activities that are involved in (and are absolutely essential to) the practice of science that are not science per se according to that definition. This does not diminish their value to science. Some of this has to do with the acquisition of background knowledge that informs the hypotheses to be tested, while some of it is associated with making the results of inquiry available and comprehensible to the scientific community and the public.

So then is taxonomy art or science? With taxonomy, there is not a "right" answer, although there are plenty of wrong answers if one wishes to have a system that is informed by the results of scientific inquiry. Taxonomic units are all in some sense arbitrary. Although a group of organisms may form a "clade," whether we recognize that clade with a certain name is somewhat arbitrary. I personally like to think of taxonomic units being defined by specific innovations (morphological, molecular, ecological, etc.) that have changed the evolutionary trajectory of a group, but that rule is certainly not universally applied, and there could certainly be many alternative taxonomies even if such standards were applied.

For me, the argument for taxonomy as an art does not actually diminish taxonomy in any way as part of what we must do in order to be effective and responsible scientists. In fact, having this perspective on taxonomy can help to enhance the understanding of the significance of taxonomy for science. As scientists, we must use what we discover through the scientific process to help facilitate communication about natural phenomena. Taxonomy is a tool that we use to communicate ideas about organisms, so taxonomy is an absolutely necessary part of the pursuit of scientific truth, even if it is not "science" itself.

One test for me of whether taxonomy is itself a science in the very strictest sense of the word is whether it is directly involved in the process of hypothesis testing. One can use principles of phylogenetics, ecology, or molecular biology to test hypotheses, but taxonomic principles would not be used. When we begin to dissect some of the scientific questions that are often deemed "taxonomic questions," it can be argued that they are not actually taxonomic in nature, and that the taxonomic repercussions would really only be a byproduct of obtaining results through scientific inquiry. For instance, a question like "Is this a good genus?" is really asking something like "Do the species form a distinct clade?", which is a question that is evolutionary in nature. Likewise, the question "Do these individuals make up one species?" is perhaps just a way of saying "How can we properly apply a biological, morphological, chemical, ecological, and/or phylogenetic species concept to this group of individuals?", a question that draws on different fields of biology.

I can see that many systematists would hesitate to state that taxonomy is an art, because of what it implies. If it is an art, then it opens the door for people to say that people who do taxonomy are not really scientists at all. But a consummate scientist is not just someone who constantly tests hypotheses one after another without consideration for anything else. To be a scientist, one must also lay the groundwork for scientific pursuits, and defining the terms used to communicate ideas about specific units of the tree of life (whether or not it is itself an artistic pursuit) is crucial to the advancement of science.

- Brendan


  1. I ran into this on Panda's Thumb, and posted this there:

    I think he’s too hard on systematics. First, taxonomy has two major components, of which he mentions only one: the attachment of names to groups. But there’s also (at least) alpha taxonomy, the delimitation and description of species. The former, being arbitrary (you can pick any clade to name, and assign any name to it subject to certain likewise arbitrary rules of nomenclature), isn’t science. But I don’t know of any systematist whose work consists mainly of doing that. Instead, they do phylogenetics, which sometimes requires new taxonomies. So nobody’s going to lose a career if that sort of taxonomy is recognized as non-science. And of course the point would still remain that naming is necessary for science even if naming isn’t science.

    Then again, in alpha taxonomy there’s a clear hypothesis to be tested: this entity here is a new species, separate from all previously described ones. To the extent that alpha taxonomists actually test that hypothesis, they’re doing science. Even if the test is “this looks too different from previous specimens for me to believe they’re from the same population”.

  2. Thanks for the comment! Really all of this comes down to the definition of terms, and I understand that different people define all of these terms (taxonomy, systematics, science, etc.) differently. Certainly the practice of alpha taxonomy, no matter how you define it, involves science. At the same time, there is the argument that the hypotheses being tested are not necessarily 'taxonomic' ones. A 'species' actually only has meaning from a scientific standpoint if it can be demonstrated to conform to a specific definition (or 'concept') using observational or experimental evidence. If alpha taxonomy is defined as "the discipline concerned with finding, describing and naming species" (as Wikipedia currently has it written), then the science itself would be outside of the discipline in the strictest sense, but you would be hard pressed to do any of the aforementioned activities of an alpha taxonomist without some sort of scientific backing. There are obviously other definitions of 'alpha taxonomy' that explicitly include 'science,' so I certainly do not disagree with what you have said; I just think that it's interesting to explore alternative viewpoints!

    For me, the biggest thing that I hope people understand is that the real science (we can think in terms of phylogenetic systematics here) and taxonomy (whether it is art or science itself) must go hand-in-hand. As scientists, we can all see the treachery of doing taxonomy without any scientific backing. But there is the other side of the coin where if we are only testing hypotheses and reporting observations, we can get to a point where our words no longer express the concepts that we wish to get across, which is why it is so crucial to keep good taxonomic practices alive!

    I'm glad this generated so much discussion over on Panda's Thumb!