RESUMO
The emerging new COVID 2019 pandemic, which started in 2019 in China (Wuhan) and is caused by SARS-CoV-2, raises critical concerns due to high morbidity and mortality. As many patients are infected and the numbers still increase, this may suggest that there are different variants of the virus and some of them are more pathogenic. Besides, the virus is suspected to have various evolutionary pathways since SARS-CoV-2 belongs to the RNA viruses' family, which is characterized by a high mutation rate. Additionally, it is crucial to understand the life cycle of the virus to be able to urge antiviral studies. Genotyping studies about viruses are also important in order to understand the transmission and evolution of the virus. The genome of SARS-CoV-2 has a furin-like cleavage site in its S protein that may affect its pathogenicity. It was found that insertions and deletions in S protein have an impact on the transmission and fusion of the virus. The single nucleotide polymorphisms (SNP) genotypes are used to track the relationship of virus isolates. Se-quence alignment revealed the presence of hundreds of inter-host mutations during person-to-per-son transmission. Furthermore, genetic recombination provided a second mechanism for virus evo-lution. In this review, we highlight the life cycle of the virus and methods of virus evolution caused by mutations or recombination of viral genomes.Copyright © 2021 Bentham Science Publishers.