In the era of post-genomics,  it is no longer possible to explain life as
one-gene-one-function mapping relations. Instead, it is necessary to
understand the physiological functions of the living organism from the
dynamic interactions of biological networks.Furthermore, life is a
stochastic process rather than deterministic one. The living organism can
function very well in a large range of parameters. It depends on network
topology more than network details. Qualitative dynamic models are
powerful tools to understand functions of life from the network point of view. It further offers an analysis tool to derive principles of controlling biological networks.