Until 1973, homosexuality was considered a psychological disorder by the American Psychological Association. Which sociological perspective would be most concerned with why this was considered an illness, and what effect that diagnosis had on society

I suppose they considered homosexuality a psychological disorder/illness because it wasn't heard of before. Today, when a person comes out as a homosexual, there'll be joy and acceptance but back then, you wouldn't be considered 'normal'.  

they encountered severe weather for which they were poorly prepared.

explanation:

allergens: overstimulate the nerve system

neurotics: attack nerve cells

mutagens: damage or otherwise alter dna sequence

generators: cause defects during growth and development  

carcinogens: cause unchecked cell growth

i hope you get the idea according to me these are the effects that happened.