At the turn of this century, cardinal changes took place in the perceptions of the structure and function of proteins, as well as in the organizational principles of membrane-less organelles. As a result, the model of the organization of living matter is changing to one described by highly dynamic biological soft matter positioned at the edge of chaos. Intrinsically disordered proteins (IDPs) and membrane-less organelles are key examples of this new outlook and may represent a critical foundation of life, defining its complexity and the evolution of living things. The perceptions of protein structures and functions are changing due to the abundance of IDPs and IDP regions. It is now recognized that many cellular processes occur within proteinaceous membrane-less organelles (PLMOs) rather than only in membrane-encapsulated chambers. IDPs and PLMOs can be considered as biological soft matter. By considering IDPs and PLMOs as edge of chaos systems, a better understanding of their mechanism can be gained. Success in studying these systems depends on interdisciplinary collaborations that bridge biological studies with physical approaches. [ABSTRACT FROM AUTHOR]