I guess I was thinking along the lines of sub populations that now breed that say 300 years ago would not have bred. For instance, there are people who(m?) smallpox is not fatal. By eradicating for the most part, smallpox, have we ended up with a weaker species in comparison to a species that is genetically resistant to small pox? I guess this goes with other diseases that have high fatality rates.
Just opinion seeking. The question popped into my mind reading about the "germ warfare" waged against the Plains Indians.
My question is whether surviving a small pox infection is the result of genetics.
Amazingly, the array of B- and T-cells that are produced in an individual's bursa, is a random lot, and changes over time.
I haven't seen a study, but I'd like to compare the detailed array of lymphocytes between identical twins. Also, are there cases where one of an infected pair of twins died, whereas the other survived. That's the kind of data I'd like.