[vharuck]

Evolution is a random and long-term process. What you're thinking of is natural selection. Even that does not guarantee things will get better. For example, there was a worse second wave of Spanish Flu. Natural selection only implies there's less chance these terrible things will last. And, to adapt an economic adage, "The disease can remain deadly longer than you can remain alive."

[jacquesm]

Natural selection is the basic mechanism that enables evolution, the one is part of the other.