TIME-REVERSAL IN BIOLOGICAL-SYSTEMS

Fundamental physical laws provide us appropriate descriptions of the b asic behavior of nature. Science possesses a hierarchical structure wi th various levels of complexity and organization. This extends from th e physics of elementary particles and atomic constituents, to the chem istry of molecules, to the biology of the cell and multicellular level s, up to an individual and beyond. Molecular biology thus has its root s based upon fundamental physical descriptors of macromolecules and ch emical reactions. The purpose of this paper is to relate an operation in physics, time reversal symmetry, to the realm of biology. This is d one with regard to the process of carcinogenesis. Tumor development an d progression can be considered a microcosm of evolution, on the level of an individual organism, as well as from the aspect of evolutionary lineage. The driving forces of selection inherent in malignancy can b e considered to result in the emergence of a new biological species, w hich is characterized by reproductive immortality and a remarkable equ ivalence with our unicellular ancestors. Thus, by its very nature, car cinogenesis as a closed system conceptually represents a reversal of m otion with respect to order, stability and evolutionary standards of t ime.