Figure 1.

Timelines of the emergence of animal CoVs with significant impact on farm animals, pets, and humans. Arrow directions stand for the gene source or gene exchange direction. Animals locating vertically at individual CoV are viral hosts. CoVs in the same colour (red, green, purple) indicate that they have close relationship either gene exchange or sharing common ancestors. Blue line stands for the possible transmission route of SARS‐CoV‐2 between hosts. Thick lines strand for relative strength of infectivity [Colour figure can be viewed at wileyonlinelibrary.com]