Some radioactive iodide salts of sodium, including [ 125I ]NaI and [ 131I ]NaI, have radiopharmaceutical uses, such as in the treatment of thyroid cancer and hyperthyroidism or as radiolabeling tracers in imaging (see).
Genetic drift is defined as the changing of the number of available alleles in a population by chance events. Also called allelic drift, this phenomenon is usually due to a very small gene pool or population size.
Continental drift is the slow movement of the Earth's continents towards and away from each other. continental drift. the theory that the earth's continents move gradually over the surface of the planet on a substratum of magma. continental drift in American English. the theory that continents slowly shift their positions as a result of currents in the molten rocks of the earth's mantle, plate tectonics, etc.