and...
​identifying viral mutations associated with specific strains of Covid-19 permits variants to be analyzed and allocated a VOI or VOC 

DNA Barcoding

taxonomy, systematics
​ and phylogeny

applications for DNA barcoding include:

"preserving natural resources, protecting endangered species, controlling agriculture pests, identifying disease vectors, monitoring water quality, authentication of natural health products and identification of medicinal plants". http://pnrsolution.org

and...
​https://www.courthousenews.com/dna-used-in-crackdown-on-seafood-fraud/
​
https://www.sciencedirect.com/science/article/abs/pii/S0956713520300591

Fraudulent labelling has become an area of concern
in the food industry.  ​A Canadian study showed that 20% of the imported seafood tested was mislabelled when it arrived in Canada. The mislabelling increased to 27% at wholesaler level, and 40% at retail level.
​

DNA barcoding is a method used to identify species based on variations in a section of DNA from a specific gene or genes.​

A phylogeny is the evolutionary relationships among a group of species 

while the study of the kinds and diversity of organisms is called systematics.
Phylogenetic systematics is the name given to an area of biology that reconstructs evolutionary history by examining the
relationships among organisms. 

the 3 domain system

   when studying evolutionary history and        assembling cladograms, several data set                                can be used:
*fossil records
*morphology (analogies and homologies)
*behavioral traits
*molecular evidence

and...
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC137877/

A gastroenterologist, Dr. Richard J. Schmidt, was convicted of second-degree murder of a 33-year-old nurse, allegedly telling her a deadly injection of HIV + blood was a vitamin B-12 shot. Schmidt drew the blood of an HIV-positive patient under his care and injected it into his ex-girlfriend to get even with her trying to break off their relationship.
"Phylogenetic analyses of HIV-1 sequences were admitted and used as evidence in this case, representing the first use of phylogenetic analyses in a criminal court case in the United States. Phylogenetic analyses of HIV-1 reverse transcriptase and env DNA sequences isolated from the victim, the patient, and a local population sample of HIV-1-positive individuals showed the victim's HIV-1 sequences to be most closely related to and nested within a lineage comprised of the patient's HIV-1 sequences." 

​https://www.wired.com/story/strands-of-evidence-genetic-testing-trial/​

using a cladogram

and...

taxonomists classify organisms by their shared evolutionary history, constructing a family tree called a
​phylogeny.

The term systematics is somewhat sometimes synonymous with the term taxonomy. Taxonomy identifies, classifies and names organisms while systematics references specifically the evolutionary history of organisms.

n 1977, Carl Woese proposed a new third domain of life known as the Archaea which led to a redo of the tree of life. We now organize life into three domains:
 Bacteria, Archaea and Eukarya.
Bacterial cells do not contain a nucleus.
Archaea cells also do not contain a nucleus but they have a different cell wall from bacteria. Eukarya cells do contain a nucleus.
The old system grouped organisms into one of 5 kingdoms. A domain is a taxonomic category above kingdom.

taxonomy classifies, describes and identifies by a detailed naming process   all organisms

cladograms are diagram that shows relationships between species. the end product resembles tree with branches that show common ancestry as a point of divergence between 
branches displaying a new phenotype unique to that branch.