Early in the twentieth century it was shown that Mendel's laws apply to plants and animals and that genes reside on chromosomes. In the 1950s the double-helix model of DNA inaugurated the molecular biology era, which culminated at the end of the century with the publication of the human genome sequence. Although the early response to discoveries in genetics was slow in Mexico, the Green Revolution and other agricultural applications of genetic knowledge contributed greatly to economic welfare, and by the end of the millennium Mexican genetics had reached world-class status at several universities and research institutions.