 A policing mechanism “is any mechanism that inhibits the capacity of an object to undergo within-object selection” (Clarke 2013: 421), typically by decreasing the genetic variation between parts of an object. This decreases the chance that the object’s parts will undergo selection that disrupts the integration of those parts. There is a sense in which demarcating mechanisms operate in just the opposite way. Rather than working to constrain or limit selective processes amongst an individual’s parts, a demarcating mechanism “increases or maintains the capacity of an object to undergo between-object selection” (2013: 424), doing so by promoting the variation (between objects) that fuels selection.