"In comparison of SARS-CoV-2 WIV04 with Bat-SARSr-CoV RaTG13, the ratios of non-synonymous to synonymous substitution rates (dN/dS) was the lowest among all performed comparisons, reconfirming the evolution of SARS-CoV-2 under stringent selective pressure. Moreover, some sites of spike protein might be subjected to positive selection. Therefore, our results will help understanding the evolutionary mechanisms contribute to viral pathogenicity and its adaptation with hosts."

https://www.biorxiv.org/content/10.1101/2020.02.27.969006v1#disqus_thread

Thoughts?