researchers describe how they went on to compare the structure of the pandemic coronavirus with related strains found in bats and pangolins. They found that both animal strains could bind to the same human ACE-2 receptor, supporting previous work that suggests the human coronavirus came from bats either directly, or via pangolins that themselves became infected by bats. Before infecting humans, the animal strains picked up key mutations that allowed the virus to spread more easily in humans.
