Origin and Evolution of SARS-CoV-2: An Enigma

SARS-CoV-2 has caught much attention due to its highly contagious nature which caused COVID-19 outbreak. Viruses have been known to evolve in response to natural selection and as a result of drug-based interventions mainly by incorporating mutations. The substantial effect of SARS-CoV-2 variants on its transmission and disease severity is prompting scientists to explore the evolutionary processes. This review summarizes different theories of SARS-CoV-2 evolution that have been put forward by different scientific schools of thought to describe the origin of SARS-CoV-2 and the possibility of bats for being its natural reservoirs. Furthermore, insights from the phylogenetic tree analysis depict divergence of VOCs of SARS-CoV-2 from the original strain in a short span of time. As evident from the genomic and phylogenetic studies, bats host a range of coronaviruses having ability for inter-species host switching, there is high probability for the potential spillovers that might lead to COVID-19-like pandemics in future