Early in the days of natural history, man tried to explain the human body as a machine. This worked for certain aspects such as the bones and muscles, which operated much like levels and pumps, but other physiological processes such as digestion proved much move complicated. Growth and reproduction were impossible to describe by the mechanists. Advances in chemistry gave us a clearer idea about digestion and some other processes, but the basics of growth and reproduction were not truly understood until the discovery of DNA in 1869.
With more and more information on cellular components and the “mechanics” of molecular processes, there seems to be a return to mechanical thinking. “Nanobots” are a hot new area of research. Tiny machines can swim through the body seeking out cancer cells, opening blood vessels, repairing cellular damage. Are nanobots the future? or are we sending a machine to do what a nucleic acid could do better?