This view has been unpopular in part because it has little direct application in nonfundamental sciences, such as biology. The causal claims biologists make usually don’t involve explicit reference to conserved quantities (even if they presuppose such notions fundamentally) (Glennan 2002; Craver 2007). Furthermore, biological mechanisms often involve causation by omission, prevention, and double prevention (that is, when a mechanism works by removing a cause, preventing a cause, or inhibiting an inhibitor) (Schaffer 2000, 2004). Such forms of causal disconnection are ubiquitous in the special sciences.