  Quantifying the adaptive landscape in a given dynamical processes has been
one of most important goals in theoretical biology. It can have immediate
implications for many dynamical properties, such as robustness and plasticity.
Based on recent work here I give a nontechnical brief review of this powerful
quantitative concept in biology. This concept was initially proposed by S
Wright 70 years ago, re-introduced by one of the founders of molecular biology
and by others in different biological contexts. It was apparently forgotten by
mainstream modern biologists for many years. Currently, this concept has found
its increasingly important role in the development of systems biology and the
modeling of bionetwork dynamics, from phage lambda genetic switch to endogenous
network of cancer genesis and progression. It is an ideal quantify to describe
the robustness and stability of bionetworks. I will first introduce five
landmark proposals in biology on this concept, to demonstrate the important
common thread in its theoretical biology development. Then I will discuss a few
recent results, focusing on the work showing the logical consistency of
adaptive landscape. From the perspective of a working scientist and of what
needed for a dynamical theory when confronting empirical data, the adaptive
landscape is useful both metaphorically and quantitatively and has captured an
essential aspect of biological dynamical processes. Still, many important open
problems remain to be solved. Having this important problem under control, we
may expect that we are on the right road to quantitatively formulate the
evolutionary dynamics discovered by Darwin and Wallace.
