GENETICS AND AMERICAN SCIENCE

Humans engaged in the practical studies of heredity from ancient times. These practical studies were essential in arenas such as agricultural plant and animal breeding. Genetics as a scientific discipline began in the seventeenth century, and the most significant of the early breakthroughs in the field was the determination of the basic mechanisms of inheritance by Gregor Mendel in 1868. Important work in cytogenetic followed in the later eighteenth century and the unification of natural selection and Mendelian principles followed in the early twentieth century. By the mid twentieth century, the material of heredity was discovered in the form of deoxyribonucleic acid (DNA). This article outlines the contributions of American scientists to the growth of genetics in the twentieth century. It concludes with discussions of modern issues related to new technologies that are heralding unparalleled opportunities for greater control of biological systems.