we can see evolution in human populations as well.
most obvious is the development of sickle cell and thalassemia in areas with malaria where these genetic disorders actually confer survival advantage. and therefore the population actually develop more folks with these conditions.
another is the “islander metabolism.” due to the feast and famine type of condition in small islands, as well as lack of significant farming which means in general less carbohydrate in traditional diet, islanders evolve by selecting for folks that can be the most efficient at storing energy from the least amount of nutrient. it is no wonder that once those of islander ancestry are exposed to plentiful carbohyrate, the entire society become morbidly obese.
