Tonic water and other tropical posts mixed the powder with soda and sugar, and tonic water was created. The first commercial tonic water was produced in 1858. The mixed drink gin and tonic also originated in British colonial India, when the British mixed their medicinal quinine tonic with gin. Since 2010, at least four tonic syrups have been available in the US. Consumers add carbonated water to the syrup to make tonic water, allowing drinkers to adjust the flavor intensity. Medicinal tonic water originally contained only carbonated water and a large amount of quinine. However, most tonic water today contains less quinine
Human genetic resistance to malaria foothold among African populations until larger sedentary communities emerged in association with the evolution of domestic agriculture in Africa (the agricultural revolution). Several inherited variants in red blood cells have become common in parts of the world where malaria is frequent as a result of selection exerted by this parasite. This selection was historically important as the first documented example of disease as an agent of natural selection in humans. It was also the first example of genetically controlled innate immunity that operates early in the course of infections, preceding adaptive immunity which exerts effects after several days. In malaria,