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[Explainer] How are species named?

  • The Linnaean or binomial system of nomenclature for naming organisms has been in use for over 200 years and is a cornerstone of taxonomy.
  • The conventions followed in naming species have recently come under scrutiny, especially in cases of eponyms or scientific names based on people’s names.
  • The Indian scientific community often uses a combination of eponymous names and local names when naming species.

The science of biology would be nothing without names.

One of the first steps in studies involving living organisms is taxonomy – the process of discovering an organism’s scientific name or naming it, if it is newly discovered. Without taxonomy, every subfield of biology would descend into chaos.

Although several systems of taxonomy have been created and modified, the one that persists today, over 200 years after it was first developed, is Linnaeus’ binomial system of nomenclature, developed by Carl Linnaeus, famous for his work in taxonomy or the science of identifying, naming and classifying organisms. This system standardises the naming of species to classify them according to their characteristics and relationships with each other and is the cornerstone of taxonomy.

What is the binomial system of nomenclature?

The binomial system of nomenclature is where names assigned to organisms use a combination of two Latin words – one denoting the genus and the other for the species, similar to the usage of a name and a surname to identify a person. In biological classification, genus refers to a group of organisms with similar characteristics which is composed of species, that refers to similar individuals that are capable of interbreeding and producing fertile offspring.

Taxonomy is critically important in helping [to] understand and conserve biodiversity. I like to think Linnaeus faced the first bioinformatics crisis: the problem of organising information about the increasing number of species that were being discovered in the eighteenth century, and he developed solutions using the best technologies available at the time,” noted Charles Godfray, a population biologist and the director of the Oxford Martin School.

The binomial system has been established so that organisms can be identified precisely and accurately for the sake of scientific communication and data sharing. This is important because the same organism can have several different names depending on its geographical location and the language spoken in that region. For example, the common house crow, ubiquitous in South and Southeast Asia, is called kowwa in Hindi, kaakaa in Tamil, gagak rumah in Malay, and kkamagwi in Korean. In the binomial system, this bird is known as Corvus splendens. When this name is used in scientific communication, scientists in India, Malaysia, Korea or anywhere in the world, know exactly which organism is being referred to.

According to the current system of taxonomy, each organism can be classified based on a system of grouping that identifies what domain, kingdom, phylum, class, order, family, genus, species and subspecies it belongs to.

The main taxonomic ranks: domain, kingdom, phylum, class, order, family, genus, and species. Image by Annina Breen via Wikimedia Commons (CC BY-SA 4.0 DEED).

Consider a domesticated dog, Canis lupus vulgaris. Vulgaris indicates that it is a subspecies of wolves (with the species name lupus), which belong to the genus Canis within the family, Canidae. The family Canidae, in turn belongs to the order Carnivora, which includes other families such as Felidae (cats) and Ursidae (bears). Order Carnivora belongs to the class Mammalia, which encompasses all warm-blooded, hairy or furry animals that give birth to live young. Class Mammalia belongs to phylum Chordata, which includes all animals with backbones, and all chordates belong to kingdom Animalia, which in turn, belong to the domain Eukaryota (organisms with cells having a clearly defined nucleus).

What are the limitations of the binomial nomenclature system?

Despite this careful ranking and hierarchy that groups organisms according to their common characteristics, the current taxonomic system often fails to capture the evolutionary relationships between different organisms as it is heavily focused on their physical characteristics.

For example, as per a modified form of the Linnaean binomial system, mammals are divided into 27–29 orders, each consisting of biological families. However, studies using DNA and genomic analyses indicate that despite huge variations in their physical characteristics, genetically, placental mammals may be divided into only four distinct orders.

In fact, now, microbial classification (for bacteria and viruses) almost always includes DNA analyses, and an alternate system of taxonomy, called the PhyloCode, has been proposed to replace the current system of taxonomy and nomenclature. The PhyloCode is a set of rules, principles, and recommendations for naming organisms based on their evolutionary history rather than the current system of taxonomy that is based on hierarchical grouping.

“While I appreciate the idea behind the PhyloCode, it is undeniable that the binomial system of nomenclature has certainly stood the test of time – more than two-and-a-half decades,” says Indian entomologist C.A. Viraktamath who is currently an emeritus professor at Gandhi Krishi Vigyan Kendra (GKVK) in Bengaluru. “As an old-school taxonomist, the binomial system of nomenclature is most comfortable and gives me the freedom to name species according to my preferences. For example, I have named a genus of leafhoppers Shivania after a member of my family, and one, Sohipona, after my dear friend and colleague, professor Amrit Singh Sohi,” he adds.

This convention of naming an organism after someone is known as eponymous naming. Usually, species names based on eponyms are derived from the names of their discoverers, in honour of scientists, or celebrities. The trend of eponymous naming is one that was originally started by Linnaeus himself and has been carried forward by generations of scientists.

Marengo sachintendulkar, a jumping spider native to India, dedicated to Indian cricketer Sachin Tendulkar. This convention of naming an organism after someone is known as eponymous naming. Image © dineshphotography7797 via iNaturalist (CC BY 4.0 DEED).
Marengo sachintendulkar, a jumping spider native to India, dedicated to Indian cricketer Sachin Tendulkar. This convention of naming an organism after someone is known as eponymous naming. Image © dineshphotography7797 via iNaturalist (CC BY 4.0 DEED).

Currently, the use of eponymous names is a contentious issue in the binomial nomenclature system. This is because many scientific eponyms are unfortunately associated with racism, imperialism, and slavery. For example, the wildflower genus Hibbertia, the coral Catalaphyllia jardinei, and a cave beetle, Anophthalmus hitlerii, are named after controversial figures.

In a call to change offensive eponymous names, several scientists have argued that species names associated with slavery, colonialism, imperialism, racism, and patriarchy must go, giving way to names that are descriptive and locally relevant. While one might argue that finding a name “offensive” is not a valid reason to change it, eponymous names can have an implication on the survival of a species. A case in point is the beetle, Anophthalmus hitlerii which was almost driven to extinction by Nazi memorabilia collectors.


Read more: Should species be named after people? It’s up for debate.


Should species be renamed?

Though the argument for changing species names has a strong ethical basis, there are many practical roadblocks.

First, it is difficult to change a taxonomic name. As per the principle of priority, the first formally published name of an organism is considered to be its valid or true name and any names given later are not to be recognised. Though this may seem rigid, some argue that it is essential for the stability of taxonomy. Secondly, changing the names perceived as “offensive” are often considered time consuming and expensive. Given that many species deemed important to agriculture and horticulture have already been described, changing the names of species that are commercially less relevant, is not considered worth the time and money investment, points out Viraktamath.

The ‘eyeless Hitler beetle’ Anophthalmus hitleri, 1937 at the Stuttgart State Museum of Natural History. The species was named after Adolf Hitler. After World War II, renaming the beetle was rejected by the ICZN, as the beetle’s name was originally published in full accordance with the rules set forth by the organisation. Image by NearEMPTness via Wikimedia Commons (CC BY-SA 4.0 DEED).

Another practical issue with renaming is that within a given area, many communities often have different names for an organism. This makes it difficult to choose one local name to represent the species. Many members of the International Commission on Zoological Nomenclature (ICZN) are opposed to the idea, primarily because replacing accepted scientific names because of perceived offensiveness is not, and should not be regulated by the rules that govern naming. They argue that the ICZN should refrain from making moral judgments as there are no defined criteria to ascertain how offensive a scientific name might be to a community or an individual, either now or in the future.

“We should not rename species based on what is perceived as appropriate, inappropriate, or offensive. What has been done, has been done, and changing taxonomic names could lead to a lot of confusion, which is exactly what scientists wanted to avoid when the binomial system was adopted,” says V. V. Ramamurthy, a coleopterist and former professor at the Indian Agricultural Research Institute (IARI). “Besides, who can judge the suitability of a name? Historically, some species were named after certain people because those people were thought to be honourable. As times change, so do our perceptions of what is acceptable or not and we cannot let that affect the stability of the scientific naming system,” he says.

What is the way forward?

A possible solution to the issue of scientific nomenclature is to have a blanket ban or strict supervision on using eponymous names. However, this solution is unfair to many researchers who raise funds for research and conservation by auctioning the naming rights of newly discovered species. Nonprofit organisations such as BIOPAT, The Rainforest Trust, and even the Scripps Institute, invite people and organisations to donate funds in return for choosing names for newly discovered species.

Another set of researchers suggests that eponymous names can be used to highlight local researchers, indigenous people, cultures, and places, as local knowledge is often indispensable in identifying and naming species, which needs to be acknowledged.

In addition, several reforms including decentralising international bodies that arbitrate biological nomenclature (such as the ICZN and the International Association for Plant Taxonomy or IAPT) and establishing rules and guidelines for an ethical approach to naming have been proposed. There is also a need for procedures to remove inappropriate names and flexibility in applying the principle of priority in taxonomy.

What is the scenario in India?

The Indian scientific community uses a combination of eponymous names and local names when naming species.

Many eponyms tend to be given in honour of scientists who have worked on the group of organisms that they are named after. For example, two species of crickets, Oecanthus rohiniae and Teleogryllus rohini, are named after Rohini Balakrishnan, who works extensively on crickets. A species of centipede Ethmostigmus praveeni, was named in honour of Praveen Karanth, who works on phylogenetics, phylogeography, and population genetics.

“As far as I can remember, most Indian scientists have named at least a few species after either themselves or someone they know,” says Viraktamath. He explains that the trend of eponymous names dated back to the early 1900s, when renowned entomologist Prof. Ramakrishna Ayyar named a species of thrips Veerabahuthrips, after an Indian deity with strong arms, Veerabahu. “It left a lasting impression on me and I was inspired to do something similar. So, you will see the deity Shiva immortalised in the genus name Shivapona. I am planning to name a species after the Hindu sage Dadhichi,” he adds.

The Tamil yeoman, or the Maravan (Cirrochroa thais) was chosen as Tamil Nadu’s state butterfly due to the cultural significance of its name, among other reasons. Image by Mike Prince via Flickr (CC BY 2.0 DEED).

Using local names for organisms, however, goes further back in the history of Indian taxonomy, with examples existing as early as in the 1800s. Ferdinand Schmid, a businessman, naturalist and explorer, who worked extensively on caddisflies often used Sanskrit words to name Indian species.

Naming organisms after a geographical location or habitat like the Kumbara night frog (Nyctibatrachus kumbara) or using behaviour-specific names like in the case of Sphaerotheca varshaabhu, a frog species that comes out of deep burrows only when it rains (varshaabhu in Sanskrit means “the one who comes out of the earth during rains”) are also catching on. Organisms are also named after tribes from localities where the species has been discovered like in the case of the diatom Stauroneis lepchae which is named after the Lepcha tribe in Sikkim, in recognition of a local field assistant from the tribe.

Why are regional names important?

Research on “branding” species names shows that familiar and appealing names gain maximum conservation attention. It is no surprise then that regional names for species help the locals forge deeper connections with them. For instance, naming the endangered purple or pignose frog (Nasikabatrachus sahyadrensis) as “Mahabali” frog (after the much-loved mythological king in Kerala, Mahabali, who is believed to have been banished to the underworld and emerges once a year to meet his people) has helped in getting locals excited about its sightings and conservation. Similarly, the Tamil yeoman, or the Maravan (Cirrochroa thais) was chosen as Tamil Nadu’s state butterfly due to the cultural significance of its name, among other reasons.

Ramamurthy says that as per the rules of taxonomy, a species’ name should convey information about the species which makes naming species after the location where it was found a good choice. Equally agreeable is a name that reflects a distinct characteristic of the species. “However, if neither is available, most taxonomists use eponymous names. Although there are no hard and fast rules about how to choose names, scientists must implicitly understand that these names should not ruffle feathers,” he says. Viratkamath concurs. “I have named a genus of leafhoppers that are predominantly light coloured as Sweta, which means ‘white’ in Sanskrit and another dark-coloured one Macropsis krishna as krishna in Sanskrit denotes ‘dark-skinned’,” he explains.

Although a rose by any other name may smell just as sweet, a frog or butterfly named appropriately is likely to attract better conservation efforts than one that is not.

 

Banner image: Kumbara night frog or Nyctibatrachus kumbara. The specific epithet “kumbara” comes from the Kannada language and refers to a community known for pottery. This name is a reference to the frog’s method of parental care where the eggs are packed with mud for protection. Image © 2014 Dr. Gururaja K.V. Acharya via CalPhotos (CC BY-NC-SA 3.0 DEED).

 

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