A short article designed to provide an introduction to natural and behavioral sciences whose connections merit explicit connection in the MSC scheme: Chemistry, Biology, Genetics, Medicine, Psychology, Sociology, and other social sciences as a group. In chemistry and biochemistry, it is clear that graph theory, differential geometry, and differential equations play a role. Medical technology uses techniques of information transfer and visualization. Biology (including taxonomy and archaeobiology) uses statistical inference and other tools.Economics and finance also make use of statistical tools, especially time-series analysis; some topics, such as voting theory, are more combinatorial. The more behavioural sciences (including Linguistics) use a medley of statistical techniques, including experimental design and other rather combinatorial topics. History; applications and related fields and subfields; textbooks, reference works, and tutorials; software and tables; other web sites with this focus.