Physics.  More specifically, &#x27;conditions&#x27;.  More specifically, the environment in which the ingredients are produced determines how the ingredients assemble.  The analogy to the ingredients list is a decent one, but it is also a tad misleading.  You generally do require knowledge of the environment to figure out how the parts will assemble, but many of the parts <i>do</i> work in many different environments and can be considered whole and separable objects rather than ingredients.  But trying to separate evolution&#x2F;life from its environment is the first mistake a student makes when studying evolution.  As a grandparent stated, if the genes are the starting positions in Conway&#x27;s Game of Life, the laws of physics are the rules of the game, and the physical conditions (temperature, pH, gravity, time, etc.) are the topology and specifics of the board you&#x27;ll be playing on.  Then you just hit play and certain concepts self-assemble - the flier, the block, the boat, etc.  Some can then be used as objects in themselves, some can be used structurally, some can be used to build&#x2F;destroy structure - that is life.