a, Based on nucleotide sequences of the S gene. b, Based on nucleotide sequences of the RdRp gene. The phylogenetic trees were constructed by RAxML with the substitution model GTRGAMMAI and 1,000 bootstrap replicates. Numbers (>70) above or below branches are percentage bootstrap values for the associated nodes. The scale bar represents the number of substitutions per site. Red circles indicate the pangolin coronavirus sequences generated in this study, and blue triangles indicate SARS-CoV-2 sequences from humans.