The "thread of life", is deoxyribonucleic acid, otherwise known as DNA. It is the spiral shaped molecule found in the nucleus of cells. Scientists have known since 1952 that DNA is the basic substance of heredity. This was hypothesized, and later confirmed by James D. Watson and Francis Crick. They also know that it acts like a biological computer program over 3 billion bits long that "spells" out instructions for making the basic building blocks of life. DNA carries the bodies genetic code, controls the development of an embryo, is c ....