Studying Evolutionary Adaptation of SARS-CoV-2

Although the acute respiratory syndromes causing SARS-Coronaviruses are not new to humanity, the recent SARS-CoV-2 based epidemic has spread to almost every part of the world and claimed a large number of human lives without any discrimination of race, gender, and color. However, multiple issues related to its origin, its transfer time in humans, evolutionary patterns, and underlying forces that derived the SARS-CoV-2 outbreak and pandemic remain unclear. Knowing the pathogen is an essential step to devise appropriate strategies for controlling and treating associated infection. This chapter attempts to enhance knowledge regarding the history of SARSCoV- 2 origin, zoonotic transfer events, and related evolutionary adaptions. This manuscript also provides an overview of various factors that contributed to making this virus more compatible with infecting the human cell and evaluated the possibility of its engineered / laboratory-based emergence. Our in-depth literature analysis demonstrated that SARS-CoV-2 was possibly pre-adopted in different animal species. Molecular fingerprints and phylogenetic analysis have confirmed high similarity (96% and 84%, respectively) of SARS-CoV-2 with bats (RaTG13) and pangolins SARS-CoV-like coronavirus. The genomic similarities of SARS-CoV-2 are due to the spike glycoprotein and RBD domain and poly cleavage site with bats and pangolin coronaviruses. It conclusively suggests that it is not a man-made bioweapon but rather emerged naturally through the recombination process. Thus generated information may help develop effective treatment strategies for SARS-CoV-2 and avoid the high risk of its re-emergence in the future.

Keywords: Coronaviruses, Evolutionary Adaptation, Phylogenetic Analysis, Recombination, SARS-CoV-2, SARS-CoV-like Coronavirus, Zoonotic Transfer.