Since the dawn of western science, scientists have taken organisms, organs, tissues, cells, and macromolecules apart, and have isolated their components to understand their properties and how they function in living systems. This approach often referred to as reductionism, reducing the whole to simpler, more understandable components. As the mainstay of modern science, this approach has given us unprecedented insight into the nature of living systems. Accumulation of facts about these parts of living systems, e.g., individual genes, is occurring at an astounding rate. Increasingly, however, scientists are recognizing the need to put the pieces back together to understand how they work as a system.
Biological systems are among the most complex known.
Take the human brain for example. The article goes on to look at the brain from different perspectives. Besides being structurally complex in its circuitry, the issue of functional complexity was also raised. Many neurons fire at a predictable rate at steady-state conditions. Consider the constant and automatic adjustment of blood pressure during changes in posture, exercise, etc.