Could disease also play a part in evolution? A pandemic of some highly virulent form of the flu, lead to accelerated evolution? I'm thinking of a pandemic with a survival rate of ~1%?
There exist deleterious traits in the human population that were likely maintained because of heterozygote variations that conferred disease resistance. But what you're talking about
: a fast spreading superdisease that probably uses multiple vectors and kills off 99% of a population is science fiction. That it would be conductive to human genetic variation? The opposite would be true in a prehistoric era with low populations.