Every day, Covid mutates. Many times. Most of the mutations are harmless or ineffective. Some—as everyone knows by now—are not, and can evade immunity and change the virus to better infect humans. Right now, doctors in Canada are worried about emerging variants spiking infections this fall. But how worried should they be?Today we'll go inside the network of scientists that coordinate their efforts to better understand each emerging variant, how much of a threat it might pose, and what we need to watch out for. Before you read about a new rise in infections in the news, these are the folks sounding the alarms.GUEST: Dr. Sarah Otto, evolutionary biologist, professor at the UBC’s department of zoology, expert at the Coronavirus Variants Rapid Response Network.