Evolutionary adaptability of biological macromolecules.

The degree of gradualism with which tertiary structure and function of protein changes with stepwise changes in primary structure (assumed to be influenced by redundancy of weak bonding) is both a precondition for and consequence of evolution. The resulting selection for degree of gradualism has implications for a number of structural and functional properties of modern proteins as well as for the significance of neutral (so-called non-Darwinian) phenomena in relation to selection.