- Viruses were here before people.
- There are some theories about where viruses originated.
- The new system reflects the degree of evolutionary changes of different viruses and is more detailed.
Coronavirus is still a main topic on the news and social media around the world. Currently there are over 3.1 million of the infected and over 217,000 deaths around the globe. As a result of the latest COVID-19 pandemic scientists decided to use new virus classifications. The new system will have better spread and will essentially allow them to track the mutations of the viruses. This will allow more precise research.
The work is published on behalf of the International Committee on Taxonomy of Viruses (ICTV) Executive Committee and titled “The new scope of virus taxonomy: partitioning the virosphere into 15 hierarchical ranks.”
The ICTV authorizes and organizes the taxonomic classification of and the nomenclatures for viruses. The ICTV has developed a universal taxonomic scheme for viruses, and thus has the means to appropriately describe, name, and classify every virus that affects living organisms. The members of the ICTV are considered expert virologists. The ICTV was formed from and is governed by the Virology Division of the International Union of Microbiological Societies.
Viruses are always around us and were on planet Earth before people. Also, they can transfer DNA from one species to another. Only at the end of the 19th century did the term “viruses” appear. Biology, or rather one of its sections – Microbiology, began to study new microorganisms that, as it turned out, have long been adjacent to humans and contribute to the deterioration of their health.
In order to fight viruses more effectively, a new science has emerged – Virology. The term “virus” is derived from the Latin word Venenum (poison). It perfectly conveys the parasitic essence of microorganisms, because they do not have a cellular structure and can not exist outside of another cell. Viruses can only reproduce and develop by entering the host cell. Scientists attribute the emergence of viruses to the most ancient times on the planet. Although it is impossible to say exactly how they appeared and what form they had at that time.
Thus far there are two theories about how viruses originated:
1) They were part of DNA and eventually separated.
2) They were embedded in the genome initially and under certain circumstances and began to multiply.
Prior to the current virus classification system, the classifications were:
- Consist of double-stranded DNA.
- Contain single-stranded DNA
- Viruses that copy their RNA.
- Contain single-stranded RNA
- Transform RNA into DNA
- Transform double-stranded DNA through RNA.
The accumulated statistics show that the genetic diversity of viruses is very high. It is comparable to, or even surpasses, the diversity of cellular life forms.
Therefore, after several years of intensive discussions, ICTV introduced a new classification of viruses. Ten new ranks have been added to the previous five. Now the complete ranking system looks like this: species, genus, subgenus, subfamily, family, suborder, order, subclass, class, subtype, type, sub-Kingdom, Kingdom, subdomain, and domain.
It is easy to see that eight out of ten new ranks are more general than the order. They were introduced to cover the most evolutionarily distant branches.
Obviously the new scheme closely resembles the classification of cellular life forms.
Here is the full chart: “Classification of EBOV and SARS-CoV in the 15-rank taxonomic hierarchy.”
The new system reflects the degree of evolutionary changes of different viruses and is more detailed.