Biophysics is an interdisciplinary science that uses the methods of physical science to study biological systems. Studies span all levels of biological organization from the molecular scale to whole organisms and ecosystems. By drawing knowledge and experimental techniques from a wide variety of disciplines, biophysicists are able to directly observe, model or manipulate structures and interactions throughout the enormous range of organizational scale presented by the life sciences.
Biocomplexity is the study of the emergence of self-organized, complex behaviors from the interaction of many simple agents. Such emergent complexity is a hallmark of life, from the organization of molecules into cellular machinery, through the organization of cells into tissues, to the organization of individuals into communities. Often, agents organize into much larger structures; those structures organize into much larger structures, etc. A classic example is the primary, secondary, tertiary, and quaternary folding of DNA into chromosomes. This system of organization allows a strand of DNA, several centimeters in length, to fold without tangling or losing function into a chromosome about one micron long. Biocomplexity is a methodology and philosophy as well as a field of study. It focuses on networks of interactions and the general rules governing such networks.