RT Journal Article SR Electronic T1 Rapid and parallel adaptive mutations in spike S1 drive clade success in SARS-CoV-2 JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.09.11.459844 DO 10.1101/2021.09.11.459844 A1 Kathryn E. Kistler A1 John Huddleston A1 Trevor Bedford YR 2021 UL http://biorxiv.org/content/early/2021/09/14/2021.09.11.459844.abstract AB Despite the appearance of variant SARS-CoV-2 viruses with altered receptorbinding or antigenic phenotypes, traditional methods for detecting adaptive evolution from sequence data do not pick up strong signals of positive selection. Here, we present a new method for identifying adaptive evolution on short evolutionary time scales with densely-sampled populations. We apply this method to SARS-CoV-2 to perform a comprehensive analysis of adaptively-evolving regions of the genome. We find that spike S1 is a focal point of adaptive evolution, but also identify positively-selected mutations in other genes that are sculpting the evolutionary trajectory of SARS-CoV-2. Protein-coding mutations in S1 are temporally-clustered and, in 2021, the ratio of nonsynonymous to synonymous divergence in S1 is more than 4 times greater than in the equivalent influenza HA1 subunit.Competing Interest StatementThe authors have declared no competing interest.