Its an urban legend that modern humans are not evolving because, medicine. The bone record for the last 50,000 years shows more evolution than the previous 1M. Probably because civilization has selected for a smaller, lower-calorie, less-aggressive social individual who can thrive in a crowded village or town.<p>There are side effects in any rapidly-evolving creature. Sports and mutations survive because they are helpful. But they can be hurtful in other, non-fatal ways. I think modern illnesses (need glasses? have a food allergy?) are unfortunate side effects of a rapidly-changing genome.