One of the central tenets of evolutionary thinking in economics, strategy, and innovation is that economic systems are continually evolving, out of equilibrium, owing to endogenous factors, such as technology, which is also intrinsically evolutionary. This view contrasts with that of neoclassical economics, which assumes the existence of equilibrium. In this chapter, we review some recent debates that show how the neoclassical notion of equilibrium traces its historical roots to classical physics, such as the first law of thermodynamics in a closed system. In reality, as indicated by these debates, economic systems are open, continually exposed to a growing diversity of technologies and artefacts and are inherently evolving out of equilibrium. A concept that acquires particular importance is that of exaptation because it implies a multitude of functions and uses that are latent in technologies and artefacts and cannot be simply pre-stated, and this is a possible source of disequilibrium.