Evolutionary origins of the SARS-CoV-2 sarbecovirus lineage responsible for the COVID-19 pandemic

Maciej F Boni; Philippe Lemey; Xiaowei Jiang; Tommy Tsan-Yuk Lam; Blair Perry; Todd Castoe; Andrew Rambaut; David L Robertson

Of importance for future emergence events is the appreciation that SARS-CoV-2 has emerged from the same horseshoe bat subgenus that harbours SARS-like coronaviruses. Another similarity between SARS-CoV and SARS-CoV-2 is their divergence time (40-70 years ago) from currently known extant bat-virus lineages ( Figure 5 ). This long divergence period indicates there are unsampled viruses circulating in horseshoe bats that have zoonotic potential . While there is clear involvement of other mammalian species -specifically pangolins for SARS-CoV-2 -as a plausible conduit for transmission to humans, there . CC-BY-NC 4.0 International license author/funder. It is made available under a The copyright holder for this preprint (which was not peer-reviewed) is the . https://doi.org/10.1101/2020.03.30.015008 doi: bioRxiv preprint 18 / 25 is no evidence pangolins are facilitating adaptation to humans. A hypothesis of snakes as intermediate hosts of SARS-CoV-2 was posited during the early epidemic phase (Ji et al., 2020) , but we found no evidence of this (Anderson, 2020; Robertson, 2020) ; see Supplementary Section 3.