The phylogenetic tree based on whole genomes showed that SARS-CoV-2 is most closely related to bat SARS-like coronavirus bat-SL-CoVZC21 (NCBI accession number MG772934) and bat-SL-CoVZC45 (NCBI accession number MG772933), which share ~89% sequence homology [[91], [92], [93]]. Their genomic organization is typical of a lineage B beta coronavirus. Further phylogenetic analysis has posited that SARS-CoV-2 is a product of recombination with previously identified bat coronaviruses, but a recent report has subsequently identified a bat CoVs sequence, RaTG13, with 92–96% sequence identity with the novel virus, demonstrating that RaTG13 is the closest relative of the SARS-CoV-2 and forms a distinct lineage from other SARS-CoVs. This rejects the hypothesis of emergence as a result of a recombination event [94,96]. Even though there are high similarities between SARS-CoV-2 S and RaTG13 S, there are two distinct differences: one is an “RRAR” furin recognition site formed by an insertion residues in the S1/S2 protease cleavage site in SARS-CoV-2, rather than the single Arginine in SARS-CoV [[97], [98], [99], [100], [101]]; the other difference is the presence of 29 variant residues between SARS-CoV-2 S and RaTG13 S, 17 of which mapped to the receptor binding domain (RBD) [97].