Abstract:
The concepts of adaptive / fitness
landscapes and adaptive peaks are a central part of much of
contemporary evolutionary biology; the concepts are introduced in
introductory texts, developed in more detail in graduate-level
treatments, and are used extensively in papers published in the major
journals in the field. The appeal of visualizing the process of
evolution in terms of movement on such landscapes is very strong; as
one becomes familiar with the metaphor, one often develops the feeling
that it is possible to gain deep insights into evolution by thinking
about the movement of populations on landscapes consisting of adaptive
valleys and peaks.
But,
since Wright first introduced the metaphor in 1932, the metaphor has
been the subject of persistent confusion, from equivocation over just
what the features of the landscape are meant to represent to how we
ought to expect the landscapes to look. Recent advances -
conceptual, empirical, and computational - have pointed towards the
inadequacy and indeed incoherence of the landscapes as usually
pictured. I argue that attempts to reform the metaphor are
misguided; it is time to give up the metaphor of the landscape entirely
and rely instead on the results of formal modeling, however difficult
such results are to understand in 'intuitive' terms.