Is Adaptive Landscape in Biology a Metaphor or a Quantitative Concept? or Both?

Some biologists accept Wright's adaptive landscape idea, believing it is one of most profound concepts in evolutionary dynamics. Some wouldn't, believing that " the idea that there is such a quantity remains one of the most widely held popular misconceptions about evolution. " The two groups usually have very limited communication with each other. The paper of Poelwijk, Kiviet, Weinreich, and Tans (Nature, 445: 383-386(2007)) is an example. Sometimes such isolation can be good, because it protects budding ideas in a harsh environment. Thanks to the theoretical and experimental progress during past few years, time may have arrived to consider both sides seriously. Present letter is an attempt to bridge this gap, by pointing out two misrepresentations and one resulting error in Poelwijk et al.