A complete description of the interplay of all processes that sustain the life of an organism or species and how these change in time and space—for instance on a daily basis, or with changing environmental conditions. Such a description integrates all aspects of an organism’s biology, from its genes and proteins, through cellular metabolism and biochemistry, to anatomy. Attempts are underway to fulfil this goal for humans and other species by linking databases and computer models that focus on particular systems or networks, such as genomics, proteomics, and signal pathways, to form a single framework. Data from allied fields, such as pharmacology and pathology, are also incorporated. One ambition is to construct a virtual physiological human, as a means of facilitating understanding, predicting responses to drugs, diagnosing disease, etc.