>>12368362Of course not, it's basic logic. Nobody said that viruses can't be practically invisible for months or years and eventually be deadly over time or only be deadly in a certain percentage of the population or both though. Obviously a virus that just killed everyone from the get-go wouldn't spread. Viral traits that make them virulent and able to better infect hosts also tend to make them more deadly/harmful. Evolution of viruses is a balancing act and many end up at different places. The flu is pretty harmless but it's so virulent and quick to mutate that it continues on for centuries. HIV is almost always deadly which would greatly decrease its "viral fitness" if it weren't for the fact that it remains latent in the body for decades before it becomes deadly, giving it time to spread. Natural selection/evolution is more of a statement of logic derived from observations than some nebulous scientific concept, and is directly applicable to your image.
