Oct 28: What’s In a Name?

A portion of what we are interested in doing on this trip is no less than a cornerstone of the Biological Sciences. Everyone remembers, or at least should, from middle school Biology, the Linnaean Hierarchy. As formally defined, this hierarchy serves as the foundation for all of modern taxonomy (that is, naming names). And in case you don’t remember the hierarchy here is a quick reminder using sturgeon as a guide

Kingdom           Animalia
Phylum             Chordata
Class                  Actinopterygii
Order                Acipenseriformes
Family              Acipenseridae
Genus               Acipenser
Species             stellatus

Pretty great in its simplicity, really. And through worldwide usage it allows a common language for communicating a specific set of ideas. Specifically, when any one individual anywhere in the world is talking about Homo sapiens, everyone else in the world would know that they are talking about human beings.

So with this short recap in mind, we thought it would be fun to ask “What is in a name?” Specifically what is in a scientific name, like the ones outlined above for a given level of information (e.g. Homo sapiens or Acipenser stellatus)

Not surprisingly, there is actually quite a lot! And this importance of names is everywhere: On our first day in Moscow we were to meet at the Zoological Museum at 10 a.m. We were told to go to a green building on the corner of 2 streets. We thought that we were in the correct place, but we were, in fact, several blocks off. We knew the name of where we were supposed to be, but we are unable to read the street names. As such, we were late. Indeed, names have quite a lot of importance!

Two green buildings on the corner that both look remarkably like museums. Left, the Zoological Museum of Moscow University. Right, the first green building we went to, which we found was a movie theater... if only we could read Russian!

First, like all scientific endeavors, the name given to an animal (or any form of life) is a hypothesis. Meaning that it is a strict and explicit proposal that, as formalized, becomes available to others for further testing.

These formalizations occur through rigorous scientific inquiry. There is the scientist, working on a group of organisms (in our case sturgeon) that is his or her specialty. Their job is to painstakingly and meticulously document every detail that they can (e.g. external and internal morphology, skeletal anatomy, DNA sequence information) to provide data for comparison to other closely related species to determine if what they are seeing is unique or not. Names are given to species based on the fact that they are discernable from other species that they are closely related to. So, for example, if you have two fish in your hand, and you can tell them apart based on some characteristic(s) there is a chance that with a lot of work you can fit the animal into the hierarchy, provide a formal description and designate the new organism as a species.

Ok, so we know there is a hierarchy of information for every species known (Kingdom, Phylum, etc.) and that there are people working diligently to assign species and higher category names to groups that are their specialty. So why then a post about names?
Well, essentially, science is a human endeavor, and humans can and do make mistakes. The same then must obviously be true for taxonomy, species names and the hierarchy. In short, sometimes people get their (species) hypothesis wrong.

Pseudoscaphirhynchus kaufmanni ZMMU syntype

So, let’s think about sturgeon (the focus of this trip). Sturgeon are taxonomically assigned to four genera: Acipenser, Huso, Pseudoscaphirhynchus, and Scaphirhynchus. Let’s say for simplicity in this argument that these four units are easily diagnosable at a level that corresponds to the Genus. There are 25 species of sturgeon recognized today. They are assigned to the four genera listed above as follows: Acipenser (17), Huso (2), Pseudoscaphirhynchus (3), and Scaphirhynchus (3), with the number in brackets indicating the number of species assigned to each genus.

The number of species assigned to the genus Acipenser is a bit misleading. If we look back at the taxonomic history there are no less than 115 species names that have been given by people to individual animals they saw. These names also resulted in the designation of type material – the reference specimens for a species diagnosis – that was cataloged in a natural history collection and is stored for future reference by naturalists. Through hypothesis testing the number of valid names has been decreased to 17, which if you’re keeping score at home, means that a full 98 species that were once diagnosed are no longer (currently) valid.

So that is a part of what we are doing. Looking at these individual specimens (or collections of specimens) from a given point in time and space to help determine if what we are seeing should be regarded as a valid species, or if the specimens of Acipenser baeri from Lake Baikal we looked at on Wednesday, for instance, are different from specimens of Acipenser baeri from the Volga River we examined in St. Petersburg, and should be given different names, as some researchers have proposed in the past. This is part of the detective-work aspect of what we do as taxonomic and systematic scientists.

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