What are the characteristics of the Hardy-Weinberg law?

The Hardy-Weinberg law is key to understand how evolution
works on populations. British scientist G.H. Hardy and German doctor Wilhelm Weinberg
independently proposed this theory in 1908. The Hardy-Weinberg law states that genes
remain mathematically constant in a randomly mating, closed population from one
generation to the next, unless certain disturbances occur. These disturbances include
non-random mating, selection, mutations, gene flow (immigration or emigration), genetic
drift, and bottlenecks (a population falling below a minimum size threshold). Any
population experiencing one or more of these pressures will show a change in the
frequency of one or more alleles. Over time these changes will cause the population to
evolve.

The Hardy-Weinberg law also includes mathematical
formulas to help predict the allele frequencies from one generation to the next. If you
need to learn or practice the calculations, check out the second link
below.