  Recent studies show that newly sampled monkeypox virus (MPXV) genomes exhibit
mutations consistent with Apolipoprotein B mRNA Editing Catalytic
Polypeptide-like3 (APOBEC3)-mediated editing, compared to MPXV genomes
collected earlier. It is unclear whether these single nucleotide polymorphisms
(SNPs) result from APOBEC3-induced editing or are a consequence of genetic
drift within one or more MPXV animal reservoirs. We develop a simple method
based on a generalization of the General-Time-Reversible (GTR) model to show
that the observed SNPs are likely the result of APOBEC3-induced editing. The
statistical features allow us to extract lineage information and estimate
evolutionary events.
