How Are Species Named: A Background on Binomial Nomenclature
The Latin names for wildlife and plant species follow a specific and universally accepted structure that allows us to talk about the same organism across languages, countries, disciplines, and knowledge systems. It might seem cumbersome to memorize Latin names for species that might already enjoy pleasant sounding and culturally significant local names. However, the background of the Latin naming system, known as binomial nomenclature, is interesting and useful to understand. Many Latin names are also full of stories and hidden meanings. Digging into some of these names is sometimes like deciphering a glimpse into the minds and worlds of naturalists from centuries ago.
The interest in a standardized naming system goes back many hundreds of years as scientists began classifying organisms in nature. As specimens of plant and animal species began accumulating in museums, scientists were interested in understanding how different groups of species were related to one another.
While a thorough understanding of binomial nomenclature may not be necessary for everyday use, some general background of its structure will help us navigate conservation issues and better understand the global landscape of species conservation.
Organisms are organized according to a hierarchical structure that groups them into increasingly specific categories. The system uses a series of Latin names to organize all plant and wildlife species into a classification system known as taxonomy.
The Latin naming structure that we use today was systematized by a Swedish botanist named Carl Linnaeus. Linnaeus first published his system of taxonomy in his work Systema Naturae in 1735. Linnaeus himself named many of the species we know today and published them in the 1758 edition of Systema Naturae.
The system Linnaeus developed came to be known as Linnaean taxonomy. Taxonomy is principally a system of organization through which individual species can be grouped together based on shared characteristics and lineages. Taxonomy is often what we think about when we imagine the tree of life, showing how all species are related. Linnaeus also included a process for systematically naming these groups of species known today as binomial nomenclature (or “two-term naming system”).
Much has changed about taxonomy since Linnaeus’s time. As the age of scientific exploration expanded dramatically throughout the 19th century, scientists became focused on classifying and naming everything they found in nature. Naturalists such as Alexander von Humboldt traveled the world collecting specimens of plant, wildlife, and other natural objects that were organized into classification systems. Linnaeus’s work around a naming system became his most important and lasting contributions.
Structure of the System
In binomial nomenclature, we use the two most specific levels of the hierarchy to refer to a particular organism. In the full hierarchy for a given species, we usually list seven levels: kingdom, phylum, class, order, family, genus, species. With each level, the species included in the group will become increasingly narrower.
For instance, the order carnivora contains 291 species, including all dogs, bears, cats, and seals. The family level will then narrow down to include all dogs. By the time you get to the genus, this level includes all wolves and coyotes, but foxes have been eliminated. At the species level, we might be talking about either grey wolves or eastern coyotes, but not both.
There are some basic rules for writing a species’ Latin names. In binomial nomenclature, we use two terms: the genus and species. First, the genus is capitalized. Second, the species is lower case. Third, both are written in italics. For example, the grey wolf is written as Canis lupis.
Advantages of the System
The value of a universally accepted taxonomic system is that it is possible to distinguish between species that might have different local names. Further, it allows scientists to make decisions about when two groups of a plant or animal really do constitute different species, two populations of the same species, or whether one is in fact a subspecies of another.
Sometimes we refer to one species by different local names. The tree Acer saccharum is known as both sugar maple and hard maple. While people might call it different names, it is a single genetic species.
Consider the reverse, where the same common name can be used for two different species. In Ontario, when people talk about a juniper, they are usually referring to the shrub Juniperus virginiana. In Labrador, juniper refers to the tree Larix laricina, referred to as tamarack by Ontarians. This is all complicated by the fact that many Ontarians also call juniper (the Juniperus virginiana one) red cedar, even though it is not at all a cedar, which are in the genus Thuja. Following?
With a standardized and universally accepted naming system, it is possible to ensure we are speaking about the same species regardless of common names that differ across geographic and cultural contexts.
Renaming a Species
Another advantage of the closely intertwined systems of taxonomy and naming is that as new methods emerge that allow us to better understand species, we can reclassify and rename them accordingly. Species classifications used to be based almost purely on morphological descriptions – or descriptions of an organism’s appearance and physical traits. Individuals that looked different were classified as different species.
Genetic methods in particular have allowed scientists to develop more refined understandings of which groups of organisms truly represented different species. In some cases, two individuals that look similar are actually distinct species. On the other hand, groups of wildlife that look differently may in fact simply be two different populations of the same species.
With binomial nomenclature, if additional information is discovered about a species that changes our understanding of its biology or phylogeny (its evolutionary history), we can adjust its Latin names accordingly to place it in a more appropriate taxon.
Certainly, there are times when scientists disagree about how a species should be classified and named. For example, the most common and abundant Arctic seal, the ringed seal, has bounced back and forth between the genus Phoca and the genus Pusa since it was named in the 18th century. Much of the debate is rooted in detailed understandings of the ringed seal’s molecular structure and its relationship with other seals. Most scientists now accept the name Pusa hispida for the ringed seal.
The exciting part is that a structured system of taxonomy and naming allows the stories of different species to interact with one another as our knowledge deepens so that the debate about one depends on and dances along with the debates on another. The point, though, is that as the debates rage, we can all feel confident that we are debating the same animals.
Although a completely common scientific practice and even one that has general public awareness, the history of how species are named is a rich and fascinating story. It represents an exciting time in the history of scientific knowledge and conservation.
Western science is perhaps too often presented as a kind of sterile and unemotional pursuit obsessed with objectivity. However, early naturalists and explorers were anything but objective and unemotional about their work. Naturalists and scientists such as Humboldt, Charles Darwin, John Muir, Rachel Carson expressed deep admiration and love for the natural world. It was this kind of passion that inspired creativity and it was creativity that drove people to generate new ideas such as taxonomy.
Imagine during Linnaeus’s time when naturalists had begun to collect thousands upon thousands of plant and wildlife specimens that sat piled in museums and government buildings. At the time of Linnaeus, we did not even understand the concept of ecosystems, that different areas of the world could share similar characteristics based on physical features such as temperature and elevation. We certainly hadn’t heard Darwin describe evolution by natural selection, which came with his publication of On the Origin of Species in 1859.
So it is exciting to imagine Carl Linnaeus studying countless specimens collected from around the world and working to organize, classify, and name them. He created a system that we still use today and allows us to share a common scientific language. Our task is to remember that within the Latin names of all these species is a story of passion, excitement, and love for the natural world.