ABSTRACT
Biological beings are composed of the identical set of chemical elements as non-living matter and constrained in their functions to obey the same physical laws. Yet, clearly there is some “essence” that separates the biological—the plants and animals—from the inanimate. Despite enormous advances in understanding the biochemical basis of biological function, that “something” which defines “life” remains obscure. In addressing “purpose,” one can consider that the process of Darwinian natural selection has provided a goal-directedness for living matter—to preserve the species by optimizing physiological fitness, a property that is not shared by non-living matter. Moreover, such biological purpose operates in the context of complex systems, meaning that functions are a) self-organizing (i.e., require no supreme controller), b) hierarchical (composed of strata of subsystems), and c) characterized by displaying emergent qualities (the whole—the functional outcome—is greater than can be explained by an understanding of its separate parts). In this chapter the dynamics of the response of the cardiovascular system to exercise are presented as a model of these features.
